Tex <- StackExchange top 100

Question

• How does one insert a "" (backslash) into the text of a LaTeX document?
• And how does one insert a “~” (tilde)? (If you insert \~, it will give you a tilde as an accent over the following letter.)

I believe \backslash may be used in math formulae, but not into text itself. Lamport’s, Kopka’s, and Mittelbach’s texts have said as much (but no more), and so left me hanging on how to get a backslash into regular text.

Answer accepted (score 789)

The Comprehensive LaTeX Symbol List is your friend. The correct link seems to keep changing, but if you have a complete TeX Live installation, the command texdoc symbols-a4 will display your local copy.

\textbackslash and \textasciitilde are found in several places in the document, but the LaTeX 2e ASCII Table (Table 529 as of this writing) and the following discussion are a convenient resource for all ASCII characters. In particular, the discussion notes that \~{} and \textasciitilde produce a raised tilde, whilst the math-mode $\sim$ and \texttildelow are options for a lower tilde; the latter is in the textcomp package, and looks best in fonts other than Computer Modern. If you are typesetting file names or urls, the document recommends the url package.

Remember to delimit TeX macros from surrounding text, e.g. bar\textasciitilde{}foo.

Answer 2 (score 273)

Canonical answer

There’s now an extensive discussion with a canonical answer on this website. Use the solution described there. The text below should be considered obsolete.

Old answer, preserved for posteriority

textcomp’s \texttildelow is actually quite a bad choice: it’s too low for most fonts.

A much better rendering can be achieved by the following, which tweaks the appearance of the (otherwise too wide) $\sim$:

{\raise.17ex\hbox{$\scriptstyle\sim$}}

This was taken from the Arbitrary LateX reference … the page also provides a good comparison sheet:

When used in \texttt, I would add a \mathtt around the tilde, to make it fit the font better:

{\raise.17ex\hbox{$\scriptstyle\mathtt{\sim}$}}

The difference is small but noticeable.

Answer 3 (score 71)

You can also use the “plain TeX” method of indexing the actual ascii character in the current font:

\char`\\
\char`\~

I often use the former for writing macros that need the backslash in the typewriter font; \textbackslash will sometimes still use the roman font depending on the font setup. Of course, if you’re using these a lot you should define your own macro for them:

\newcommand\SLASH{\char`\\}

Question

I want to place 2 images side by side in LaTeX. I have 2 .png files and I don’t understand how to do it in LaTeX. I have tried many ways but could not get a good result.

Answer 2 (score 408)

For two independent side-by-side figures, you can use two minipages inside a figure enviroment; for two subfigures, I would recommend the subcaption package with its subfigure environment; here’s an example showing both approaches:

\documentclass{article}
\\usepackage[demo]{graphicx}
\\usepackage{caption}
\\usepackage{subcaption}

\begin{document}

\begin{figure}
\centering
\begin{subfigure}{.5\textwidth}
  \centering
  \includegraphics[width=.4\linewidth]{image1}
  \caption{A subfigure}
  \label{fig:sub1}
\end{subfigure}%
\begin{subfigure}{.5\textwidth}
  \centering
  \includegraphics[width=.4\linewidth]{image1}
  \caption{A subfigure}
  \label{fig:sub2}
\end{subfigure}
\caption{A figure with two subfigures}
\label{fig:test}
\end{figure}

\begin{figure}
\centering
\begin{minipage}{.5\textwidth}
  \centering
  \includegraphics[width=.4\linewidth]{image1}
  \captionof{figure}{A figure}
  \label{fig:test1}
\end{minipage}%
\begin{minipage}{.5\textwidth}
  \centering
  \includegraphics[width=.4\linewidth]{image1}
  \captionof{figure}{Another figure}
  \label{fig:test2}
\end{minipage}
\end{figure}

\end{document}

The demo option for graphicx was used only to make my example compilable for everyone; you shouldn’t use that option in your actual code.

The % (between \end{subfigure} and \begin{subfigure} or minipage) is really important; not suppressing it will cause a spurious blank space to be added, the total length will surpass and the figures will end up not side-by-side.

Answer 3 (score 89)

\\usepackage{subfig}

The PDF documentation with lots of examples can be found here: subfig.pdf

Note that you’ll see a lot of references to “subfigure” on the net, but that’s outdated now.

Here is a small example taken from the documentation

\documentclass[10pt,a4paper]{article}
\\usepackage[demo]{graphicx}
\\usepackage{subfig}
\begin{document}
\begin{figure}%
    \centering
    \subfloat[label 1]{{\includegraphics[width=5cm]{img1} }}%
    \qquad
    \subfloat[label 2]{{\includegraphics[width=5cm]{img2} }}%
    \caption{2 Figures side by side}%
    \label{fig:example}%
\end{figure}
\end{document}

Output:

Question

I have a problem when a lot of figures are in question. Some figures tend to “fly around”, that is, be a paragraph below, although I placed them before that paragraph. I use code:

\begin{figure}[ht]
\begin{center}
\advance\leftskip-3cm
\advance\rightskip-3cm
\includegraphics[keepaspectratio=true,scale=0.6]{slike/visina8}
\caption{}
\label{visina8}
\end{center}\end{figure}

to place my figures. How can I tell latex I REALLY want the figure in that specific place, no matter how much whitespace will be left?

Answer accepted (score 548)

The short answer: use the “float” package and then the [H] option for your figure.

\\usepackage{float}

...

\begin{figure}[H]
\centering
\includegraphics{slike/visina8}
\caption{Write some caption here}\label{visina8}
\end{figure}

The longer answer: The default behaviour of figures is to float, so that LaTeX can find the best way to arrange them in your document and make it look better. If you have a look, this is how books are often typeset. So, usually the best thing to do is just to let LaTeX do its work and don’t try to force the placement of figures at specific locations. This also means that you should avoid using phrases such as “in the following figure:”, which requires the figure to be set a specific location, and use “in Figure~\ref{..}“ instead, taking advantage of LaTeX’s cross-references.

If for some reason you really want some particular figure to be placed “HERE”, and not where LaTeX wants to put it, then use the [H] option of the “float” package which basically turns the floating figure into a regular non-float.

Also note that, if you don’t want to add a caption to your figure, then you don’t need to use the figure environment at all! You can use the \includegraphics command anywhere in your document to insert an image.

Answer 2 (score 196)

do not use a floating environment if you do not want it float.

\\usepackage{caption}
...
\noindent%
\begin{minipage}{\linewidth}% to keep image and caption on one page
\makebox[\linewidth]{%        to center the image
  \includegraphics[keepaspectratio=true,scale=0.6]{slike/visina8}}
\captionof{figure}{...}\label{visina8}%      only if needed  
\end{minipage}

or

\begin{center}
  \includegraphics[...]{slike/visina8}}
\captionof{figure}{...}\label{visina8}%      only if needed  
\end{center}

Answer 3 (score 7)

One solution not mentioned by any of the other answers that just sorted me out is to use \clearpage

No special packages are needed.

\clearpage forces all figures above it in the .tex file to be printed before continuing with the text. This can leave large white spaces.

For me this was the best solution because I did not have to change any of the formatting and it just made sure that all figures were printed before the next bit of text. My issue was a part of the document with lots of figures and not much text.

Question

I’m looking to cite a number of web pages using bibtex and I was wondering if there was a specific template of the form @<template name here> for doing that. If you could use the following website as an example that would be great

http://web.archive.org/web/20080207010024/http://www.808multimedia.com/winnt/kernel.htm

Answer accepted (score 497)

A simple way of doing it in BibTeX is with a @misc entry:

@misc{WinNT,
  title = {{MS Windows NT} Kernel Description},
  howpublished = {\\url{http://web.archive.org/web/20080207010024/http://www.808multimedia.com/winnt/kernel.htm}},
  note = {Accessed: 2010-09-30}
}

You should also perhaps include an author if you know it. And remember to load a package such as hyperref or url.

If you are using BibLaTeX there is an @online entry type:

@online{WinNT,
  author = {MultiMedia LLC},
  title = {{MS Windows NT} Kernel Description},
  year = 1999,
  url = {http://web.archive.org/web/20080207010024/http://www.808multimedia.com/winnt/kernel.htm},
  urldate = {2010-09-30}
}

Answer 2 (score 63)

I always use the defaults suggested by Wikipedia (see “BibTeX entry” at the bottom), available if you click on “cite this page”.

Answer 3 (score 18)

The JabRef reference manager suggests to use the “electronic” type. So I do it like this:

@electronic{Rub1,
 author = {Rubino, Daniel},
 editor = {{Windows Phone Central}},
 title = {IE9 for Windows Phone 7: Adobe Flash, demos and development},
 url = {http://www.wpcentral.com/ie9-windows-phone-7-adobe-flash-demos-and-development-videos},
 urldate = {14.01.2013},
 originalyear = {18.02.2011}
}

In the BibTeX export of Citavi there is als the type “www”. Depending on your editor you have to define the styles “electronic” and “www”, so “misc” seems to be probably the safest.

But then you should use \bibliographystyle{alphadin} and do it like this:

@misc{Rub1,
 author = {Rubino, Daniel},
 editor = {{Windows Phone Central}},
 title = {IE9 for Windows Phone 7: Adobe Flash, demos and development},
 url = {http://www.wpcentral.com/ie9-windows-phone-7-adobe-flash-demos-and-development-videos},
 lastchecked = {14.01.2013},
 originalyear = {18.02.2011}
}

Question

I know that \: in LaTeX produces a space when rendered.

Are there any alternatives, because my LaTeX renderer doesn’t support \: (it renders it as text), and there is no help / FAQ that I can find.

Answer accepted (score 909)

There are a number of horizontal spacing macros for LaTeX:

1. \, inserts a \thinspace (equivalent to .16667em) in text mode, or \thinmuskip (equivalent to 3mu) in math mode;
2. \! inserts a negative \thinmuskip in math mode;
3. \> inserts \medmuskip (equivalent to 4.0mu plus 2.0mu minus 4.0mu) in math mode;
4. \; inserts \thickmuskip (equivalent to 5.0mu plus 5.0mu) in math mode;
5. \: is equivalent to \> (see above);
6. \enspace inserts a space of .5em in text or math mode;
7. \quad inserts a space of 1em in text or math mode;
8. \qquad inserts a space of 2em in text or math mode;
9. \kern <len> inserts a skip of <len> (may be negative) in text or math mode (a plain TeX skip);
10. \hskip <len> (similar to \kern);
11. \hspace{<len>} inserts a space of length <len> (may be negative) in math or text mode (a LaTeX \hskip);
12. \hphantom{<stuff>} inserts space of length equivalent to <stuff> in math or text mode. Should be \protected when used in fragile commands (like \caption and sectional headings);
13. \ inserts what is called a “control space” (in text or math mode);
14. ` inserts an inter-word space in text mode (and is gobbled in math mode). Similarly forand.</li> <li>~&nbsp;inserts an "unbreakable" space (similar to an HTML ) (in text or math mode);</li> <li>inserts a so-called "rubber length" or stretch between elements (in text or math mode). Note that you may need to provide a type of anchor to fill from/to; see <a href="https://tex.stackexchange.com/q/45948/5764">What is the difference betweenand`?;

Your usage should work in math mode, so try $\:$.

\documentclass{article}
\setlength{\parindent}{0pt}% Just for this example
\begin{document}

There are a number of horizontal spacing macros for LaTeX:

\begin{tabular}{lp{5cm}}
  \verb|a\,b|                    & a\,b \\
  \verb|$a\,b$|                  & $a\,b$ \\
  \verb|a\thinspace b|           & a\thinspace b \\
  \verb|$a\thinspace b$|         & $a\thinspace b$ \\
  \verb|$a\!b$|                  & $a\!b$ \\
  \verb|$a\mkern-\thinmuskip b$| & $a\mkern-\thinmuskip b$ \\
  \verb|$a\>b$|                  & $a\>b$ \\
  \verb|$a\mkern\medmuskip b$|   & $a\mkern\medmuskip b$ \\
  \verb|$a\;b$|                  & $a\;b$ \\
  \verb|$a\mkern\thickmuskip b$| & $a\mkern\thickmuskip b$ \\
  \verb|$a\:b$|                  & $a\:b$ \\
  \verb|$a\mkern\medmuskip b$|   & $a\mkern\medmuskip b$ \\
  \verb|a\enspace b|             & a\enspace b \\
  \verb|$a\enspace b$|           & $a\enspace b$ \\
  \verb|a\quad b|                & a\quad b \\
  \verb|$a\quad b$|              & $a\quad b$ \\
  \verb|a\qquad b|               & a\qquad b \\
  \verb|$a\qquad b$|             & $a\qquad b$ \\
  \verb|a\hskip 1em b|           & a\hskip 1em b \\
  \verb|$a\hskip 1em b$|         & $a\hskip 1em b$ \\
  \verb|a\kern 1pc b|            & a\kern 1pc b \\
  \verb|$a\kern 1pc b$|          & $a\kern 1pc b$ \\
  \verb|a\hspace{35pt}b|         & a\hspace{35pt}b \\
  \verb|$a\hspace{35pt}b$|       & $a\hspace{35pt}b$ \\
  \verb|axyzb|                   & axyzb \\
  \verb|a\hphantom{xyz}b|        & a\hphantom{xyz}b \\
  \verb|$axyzb$|                 & $axyzb$ \\
  \verb|$a\hphantom{xyz}b$|      & $a\hphantom{xyz}b$ \\
  \verb|a{ }b|                   & a{ }b \\
  \verb|$a{ }b$|                 & $a{ }b$ \\
  \verb|a\space b|               & a\space b \\
  \verb|$a\space b$|             & $a\space b$ \\
  \verb|a\ b|                    & a\ b \\
  \verb|$a\ b$|                  & $a\ b$ \\
  \verb|a~b|                     & a~b \\
  \verb|$a~b$|                   & $a~b$ \\
  \verb|a\hfill b|               & a\hfill b \\
  \verb|$a\hfill b$|             & $a\hfill b$
\end{tabular}

\end{document}

Question

To make Latin-letter variables bold I can use e.g. \mathbf{a}, but while putting Greek letters or symbols such as \nabla inside \mathbf doesn’t cause any errors or warnings, it also doesn’t do anything else.

What is the best way to make bold math symbols, in particular Greek letters and \nabla?

Answer accepted (score 368)

The AMS Short Math Guide recommends the \boldsymbol and \pmb commands (and suggests that you use the bm package for the former to get a more powerful version than provided by amsmath).

Answer 2 (score 188)

In my experience, there is no single best way. Therefore Table 528 on page 225 of the Comprehensive LaTeX Symbol List comes in really handy. (Visited March 8, 2019 )

Answer 3 (score 54)

With unicode-math you can use \symbf{<characters>} which works for both Greek and Latin letters. (In versions of unicode-math older than 0.8 the \symXXX macros didn’t exist, but you could \mathbf{<characters>} directly.)

Compile with xelatex or lualatex.

\documentclass{article}
\\usepackage{unicode-math}
\setmathfont{xits-math.otf}
\begin{document}
\( AaBb∇αβγ \) \par
\( \symbf{AaBb∇αβγ} \) \par
\( \symrm{AaBb∇αβγ} \)
\end{document}

Question

What is the “best LaTeX practices” for writing absolute value symbols? Are there any packages which provide good methods?

Some options include |x| and \mid x \mid, but I’m not sure which is best…

Answer accepted (score 179)

I have been using the code below using \DeclarePairedDelimiter from the mathtools package.

Since I don’t think I have a case where I don’t want this to scale based on the parameter, I make use of Swap definition of starred and non-starred command so that the normal use will automatically scale, and the starred version won’t:

If you want it the other way around comment out the code between \makeatother...\makeatletter.

\documentclass{article}
\\usepackage{mathtools}

\DeclarePairedDelimiter\abs{\lvert}{\rvert}%
\DeclarePairedDelimiter\norm{\lVert}{\rVert}%

% Swap the definition of \abs* and \norm*, so that \abs
% and \norm resizes the size of the brackets, and the 
% starred version does not.
\makeatletter
\let\oldabs\abs
\def\abs{\@ifstar{\oldabs}{\oldabs*}}
%
\let\oldnorm\norm
\def\norm{\@ifstar{\oldnorm}{\oldnorm*}}
\makeatother

\newcommand*{\Value}{\frac{1}{2}x^2}%
\begin{document}
    \[\abs{\Value}  \quad \norm{\Value}  \qquad\text{non-starred}  \]
    \[\abs*{\Value} \quad \norm*{\Value} \qquad\text{starred}\qquad\]
\end{document}

Answer 2 (score 78)

Note if you just use | you get mathord spacing, which is different from the spacing you’d get from paired mathopen/mathclose delimiters or from \left/\right even if \left/\right doesn’t stretch the symbol. Personally I prefer the left/right spacing from mathinner here (even if @egreg says I’m generally wrong:-)

\documentclass{amsart}

\begin{document}

$  \log|x||y|b $

$  \log\left|x\right|\left|y\right|b $

$  \log\mathopen|x\mathclose|\mathopen|y\mathclose|b $

\end{document}

Answer 3 (score 67)

One can also use commath package.

\documentclass{article}

\\usepackage{commath}

\begin{document}
\[ \norm{a \vec{u}} = \abs{a} \, \norm{\vec{v}} \]
\end{document}

Question

I am new to Latex, and I have been trying to get the matrix of following form

    [x11 x12 x13 . . . . x1n
     x21 x22 x23 . . . . x2n
     .
     .
     .
     .
     xd1 xd2 xd3 . . . . xdn]

Where the letters accompanying the elements are subscripts ‘11 12 13’ etc. I tried it in the following fashion

    $$
    \begin{bmatrix} 
    x_{11}&x_{12}&x_{13}&.&.&.&.&x_{1n}

And so on in similar fashion. I get errors when I use the above method and I know its amateurish. Can you please tell me how to get it done the right way? I even tried including ’' for the periods. Thanks in advance.

Answer accepted (score 168)

You must read at least lshort (page 68) or amsldoc.pdf Section 4.

\documentclass{article}
\\usepackage{amsmath}
\begin{document}
\[
\begin{bmatrix}
    x_{11}       & x_{12} & x_{13} & \dots & x_{1n} \\
    x_{21}       & x_{22} & x_{23} & \dots & x_{2n} \\
    \hdotsfor{5} \\
    x_{d1}       & x_{d2} & x_{d3} & \dots & x_{dn}
\end{bmatrix}
=
\begin{bmatrix}
    x_{11} & x_{12} & x_{13} & \dots  & x_{1n} \\
    x_{21} & x_{22} & x_{23} & \dots  & x_{2n} \\
    \vdots & \vdots & \vdots & \ddots & \vdots \\
    x_{d1} & x_{d2} & x_{d3} & \dots  & x_{dn}
\end{bmatrix}
\]
\end{document}

Question

I need some help with creating an appendix for my thesis. I have about 10 figures which need to be in the appendix. I have a good appendix with the following code:

\appendix 
\addcontentsline{toc}{chapter}{APPENDICES}

\chapter{XXXX}

I have a main thesis.tex file where I call this appendix.tex file after the last chapter. Problems are:

1. The appendix starts without any notice that it is the appendix except for the chapter number being A, but I want to have either a separate page which says “Appendix” prior to the start of the appendix or on top of the first appendix page to explicitly say “Appendix”.
2. Now I use the \chapter{} command to have the title of the appendix but I think I will have only one chapter in the appendix. Is there some command which can make the title insited of chapter?

Answer 2 (score 198)

The appendix package could be used here; the toc and page package options and the appendices environment will do what you need:

\documentclass{book}
\\usepackage[toc,page]{appendix}

\begin{document}
\tableofcontents

\chapter{Regular Chapter}
\begin{appendices}
\chapter{Some Appendix}
The contents...
\end{appendices}

\end{document}

Answer 3 (score 64)

A different solution that I use is below.

\appendix
\section{\\Title of Appendix A}
% the \\ insures the section title is centered below the phrase: AppendixA

Text of Appendix A is Here

\section{\\Title of Appendix B}
% the \\ insures the section title is centered below the phrase: Appendix B

Text of Appendix B is Here

Question

Is either of these considered better/more readable/more “proper”/more conventional than the other for making text bold? If so, what is the reason?

I like my text \textbf{bold}

versus:

I like my text {\bf bold}

Answer accepted (score 353)

Marc van Dongen gave a great answer. I’ll throw in another reason:

\it and \bf do not play well together. That is, they do not nest as one would intuitively expect:

Whereas \textit and \textbf do play well together:

This is nice. However, you may notice that it still fails to handle nested style adjustments to small caps, since the Computer Modern fonts do not contain slanted or bold small caps:

If this is a problem for you, then use the slantsc package in combination with the lmodern package. slantsc provides, among other things, \rmfamily (roman), \ttfamily (typewriter/​teletype), \sffamily (sans-serif), \bfseries (boldface), \itshape (italics), \slshape (slant/​oblique), and \scshape (small caps). With these, small caps can obtained in slanted form:

As a bonus, slantsc fixes \textsl to behave properly with \textsc, so you can continue using those if you like.

Alas, I haven’t yet found a package which fixes the behavior of nested instances of \textit. In typesetting, when you nest italics, you’re supposed to come back out of italics to roman. For example, the word “Titanic” below is in nested italics (which should ideally render as roman, not italics):

Tanaka, Shelly. On Board the Titanic: What It Was Like When the Great Liner Sank. New York, NY: Hyperion/​Madison Press, 1998.

As a workaround, one can usually write \textrm to temporarily return to non-italics in those cases, but of course this is only valid if you know the exact number of nested italic levels, which may not always be the case, especially inside a macro.

Update:

As others have pointed out, \textit and \textsl do automatic italic correction, whereas \it, \itshape, \sl, and \slshape do not. Thus, you can write \textit{stuff}, but you must write {\it stuff\/} or {\itshape stuff\/} to get the same effect.

Answer 2 (score 110)

In general the command (\textbf/\textit) approach is more useful if the text is followed by more text on the same line and isn’t followed by a small punctuation symbol. If the text is in a paragraph on its own or is followed by a small punctuation symbol, it doesn’t matter really. In that case the declarations (\bf/\bfseries and \it/\itshape) are equivalent to the commands. As pointed out be others, the declarations \bf and \it are deprecated and should be avoided.

To see why the commands should be preferred, notice that \textit inserts an italic correction at the end, which adds a small horizontal compensation if the text ends in letters with long ascenders that would otherwise run into the next character. The declarations (\it and \itshape) don’t insert an italic correction.

The fourth, fifth, and sixth row in the following shows why the commands may differ from the declarations. In the fourth row you get a proper italic correction, in the fifth and the sixth you don’t and this results in the ff ligature running in to the h.

\documentclass{article}

\\usepackage{booktabs}

\begin{document}
  \Huge
  \begin{tabular}{lll}
    \toprule
    \verb|\textbf{fluff} hair|    & \textbf{fluff} hair
  \\\verb|{\bf fluff} hair|       & {\bf fluff} hair
  \\\verb|{\bfseries fluff} hair| & {\bfseries fluff} hair
  \\\midrule
    \verb|\textit{fluff} hair|    & \textit{fluff} hair
  \\\verb|{\itshape fluff} hair|  & {\itshape fluff} hair
  \\\verb|{\it fluff} hair|       & {\it fluff} hair
  \\\bottomrule
  \end{tabular}
\end{document}

Answer 3 (score 51)

First of all you should not use the obsolete \bf or \it macros from LaTeX2.0. They do not use the new font selection scheme (NFSS) of LaTeX2e. So \bf will do bold and bold only, but will not mix with an italic setting, which makes bold-italic impossible. Use the new \bfseries macro instead.

There is not much practical difference between \textbf{<content>} and {\bfseries <content>}. I would say most people use (for short texts) the first usage because it follows the common \somemacro{<content>} LaTeX style. The latter should be used if you want to make the rest of an environment/group bold, of course.

You should note that \textbf uses \bfseries internal, so the latter is a more fundamental macro. The definition of \textbf is:

\ifmmode
  \nfss@text {\bfseries #1}%
\else
  \hmode@bgroup
  \text@command {#1}%
  \bfseries \check@icl #1\check@icr
  \expandafter
  \egroup
\fi

So \textbf switches to text mode inside math mode, while \bfseries apparently doesn’t. It also adds checks for italic correction before and after the content, which is a great feature of LaTeX2e.

One benefit of \bfseries is that it doesn’t read the content as an argument, which would interfere with catcode changes required by verbatim content and other special code.

In summary I recommend \textbf for smaller texts, mainly because of the italic correction, and in math mode. \bfseries is IMHO more intended for environments and larger texts. One notable exception is if you have bold and italic (etc.) combinations, then you could write \textit{\bfseries <content>}, to avoid two sets of braces, but this is more a fashion choice. You should not use \bf in modern LaTeX documents.

Question

I am having the following equation:

\begin{equation}
  Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)} \right| + \left( \mathbf{o}_t - \hat{\mu}_m^{(s)} \right) ^T C_m^{(s)-1} \left(\mathbf{o}_t - \hat{\mu}_m^{(s)}\right) \right)
\end{equation}

which does not very well fit on one line. How can I split this over two lines? What I have in mind is that I specify the splitting place, and that the first line is left aligned and the second line right aligned to make clear that it is still the same equation.

The linebreak \\ does not work.

Answer accepted (score 164)

Use either breqn to break lines automatically or use amsmath and its many environments exactly for this purpose. For example, with breqn:

\documentclass{article}
\\usepackage{breqn}
\begin{document}
\begin{dmath}
  Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P{(O \mid \lambda )} \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)} \right| + \left( \mathbf{o}_t - \hat{\mu}_m^{(s)} \right) ^T C_m^{(s)-1} \left(\mathbf{o}_t - \hat{\mu}_m^{(s)}\right) \right)
\end{dmath}
\end{document}

Note, the expression around \mid required braces to prevent it from breaking at this point; I’m sure there is a better way to do that; anyway, here’s the output:

With amsmath, you need to specify the break points manually: (as others have also mentioned)

\\usepackage{amsmath}
...
\begin{multline}
  A+B+C+ \\ +D+E+F 
\end{multline}

The users guide to amsmath is called amsldoc.pdf, but you can access it by typing texdoc amsmath on the command line. The main environments you’ll use there would be align, split, and multline.

Answer 2 (score 97)

You can use multline or split provided by amsmath package.

• Use multline to split equations without alignment (first line left, last line right)
• Use split to split equations with alignment

Here are examples:

The corresponding source code is as follows:

(i).Use equation:
\begin{equation}
1+2+3+4+8x+7=1+2+3+4+4x+35 \\
\Rightarrow x=7
\end{equation}

(ii).Use \emph{multline} to split equations without alignment:
\begin{multline}
1+2+3+4+8x+7=1+2+3+4+4x+35 \\
\Rightarrow x=7
\end{multline}

(iii).Use \emph{split} to split equations with alignment
\begin{equation}
\begin{split}
1+2+3+4+8x+7 & =1+2+3+4+4x+35 \\
& \Rightarrow x=7
\end{split}
\end{equation}

For more info, you can refer to User’s Guide for the amsmath Package.

Answer 3 (score 41)

First line left, last line right—that is the multline environment:

\documentclass{article}
\\usepackage{amsmath}
\begin{document}
\begin{multline}
  Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \biggl( n \log(2 \pi ) \\
  + \log \left| C_m^{(s)} \right| + \left( \mathbf{o}_t - \hat{\mu}_m^{(s)} \right) ^T C_m^{(s)-1} \left(\mathbf{o}_t - \hat{\mu}_m^{(s)}\right) \biggr)
\end{multline}
\end{document}

Question

Is it possible to get a \neq but with a vertical bar instead of a slanted one? There are inequality operators like AMS’s \gvertneqq that feature this kind of “not equal” but not without mixing it with other signs.

\documentclass[a5paper]{article}
\\usepackage{amssymb}
\\usepackage{amsmath}
\begin{document}
\begin{align*}
a&\gvertneqq b\\
C&\neq \varnothing
\end{align*}
\end{document}

So what I basically would like to have is the isolated symbol under the > in the \gvertneqq above. Particularly because I don’t like the different slopes of the slashes in the second line and “≠∅” is quite a common combination.

Answer accepted (score 29)

Equal sign with vertical line

The vertical line | is a little tall for my taste. The following definition for \vneq decreases the total height of the vertical line to match the total height of \neq. Resizing vertical height will not change the line thickness in horizontal direction.

• The final witdh and height of the vertical line can be fine-tuned by redefining macros \vneqxscale and \vneqyscale. The default is 1.
• \mathpalette allows the symbol to resize automatically.

Example file:

\documentclass{article}

\\usepackage{amssymb}% \varnothing

\\usepackage{graphicx}% \resizebox
\makeatletter
\newcommand*{\vneq}{%
  \mathrel{%
    \mathpalette\@vneq{=}%
  }%
}
\newcommand*{\@vneq}[2]{%
  % #1: math style (\displaystyle, \textstyle, ...)
  % #2: symbol (=, ...)
  \sbox0{\raisebox{\depth}{$#1\neq$}}%
  \sbox2{\raisebox{\depth}{$#1|\m@th$}}%
  \ifdim\ht2>\ht0 %
    \sbox2{\resizebox{\vneqxscale\width}{\vneqyscale\ht0}{\\unhbox2}}%
  \fi
  \sbox2{$\m@th#1\vcenter{\copy2}$}%
  \ooalign{%
    \hfil\phantom{\copy2}\hfil\cr
    \hfil$#1#2\m@th$\hfil\cr
    \hfil\copy2\hfil\cr
  }%
}
\newcommand*{\vneqxscale}{1}
\newcommand*{\vneqyscale}{1}
\makeatother

\begin{document}
\[
  % Comparison \neq vs. vneq
  \varnothing \neq \emptyset \vneq \varnothing \\
\] 
\[ 
  % Check sizes:
  \vneq^{\vneq^{\vneq}} \\
\] 
\[ 
  % Bounding box checks:
  \setlength{\fboxsep}{0pt}
  \setlength{\fboxrule}{.1pt}
  \fbox{$\neq$}\,\fbox{$\vneq$}\,\fbox{$|$}
\]
\end{document}

The height can be further decreased, e.g.

\renewcommand*{\vneqyscale}{.8}

Result for mathabx:

Result for txfonts:

Result for MnSymbol:

Here the vertical line is too thick and the horizontal resizing needs shrinking:

\renewcommand*{\vneqxscale}{.67}

Result for MnSymbol and \vneqxscale = .67:

Alternative to varnothing

Instead of changing \neq, the empty set symbol \varnothing could be constructed using \not to match the slope of the slanted vertical lines. However, \circ is too small and \bigcirctoo big. Therefore this method is shown for txfonts that provides \medcirc and MnSymbol with \medcircle.

\documentclass{article}

%\\usepackage{txfonts}
%\newcommand*{\varemptysetcircle}{\medcirc}

\\usepackage{MnSymbol}
\newcommand*{\varemptysetcircle}{\medcircle}

\makeatletter
\newcommand*{\varemptyset}{%
  {% mathord
    \vphantom{\not=}% correct height and depth of the final symbol
    \mathpalette\@varemptyset\varemptysetcircle
  }%
}
\newcommand*{\@varemptyset}[2]{%
  % #1: math style (\displaystyle, \textstyle, ...)
  % #2: circle
  \ooalign{%
    \hfil$\m@th#1\not\hphantomeq$\hfil\cr
    \hfil$\m@th#1#2$\hfil\cr
  }%
}
% \not can be redefined to take an argument
\newcommand*{\hphantomeq}{%
  \mathrel{\hphantom{=}}%
}
\makeatother

\\usepackage{color}

\begin{document}
\[
  \not=\; \color{blue}\neq \varemptyset\; \color{black}\varnothing
\]
\end{document}

Result for txfonts:

Result for MnSymbol:

Answer 2 (score 21)

Yes:

\documentclass[a5paper]{article}
\\usepackage{amssymb}
\\usepackage{amsmath}
\newcommand\vneq{\mathrel{\ooalign{$=$\cr\hidewidth$|$\hidewidth\cr}}}
\begin{document}
\begin{align*}
a&\gvertneqq b\\
C&\neq \varnothing \\
d&\vneq f
\end{align*}
\end{document}

For a motivation behind the commands in \vneq, read egreg’s excellent tutorial on \ooalign in \subseteq + \circ as a single symbol (“open subset”)

Answer 3 (score 8)

A simplistic solution would be

\\usepackage{mathabx}
\changenotsign

but this would mean changing a great part of the math symbols, which is not desirable as, in my opinion, some of the symbols provided by mathabx are badly designed.

A solution with standard tools is

\documentclass{article}

\renewcommand\neq{\mathrel{\vphantom{|}\mathpalette\xsneq\relax}}
\newcommand\xsneq[2]{%
  \ooalign{\hidewidth$#1|$\hidewidth\cr$#1=$\cr}%
}

\begin{document}
$a\neq b$
\end{document}

I used \renewcommand because it will be simply a matter of removing that code in order to revert \neq to its usual shape.

By using \mathpalette, the created symbol will become smaller in subscripts or superscripts.

Question

So to “comment out” a line, I need to insert a % at the beginning of the line (so that line will not be compiled).

Is there way to comment out a large section without having to manually putting a % in front of each line?

Answer accepted (score 240)

You can use \iffalse ... \fi to make (La)TeX not compile everything between it. However, this might not work properly if you have unmatched \ifxxx ... \fi pairs inside them or do something else special with if-switches. It should be fine for normal user text.

There is also the comment package which gives you the comment environment which ignores everything in it verbatim. It allows you to define own environments and to switch them on and off.

Answer 2 (score 149)

You can use \iffalse:

\iffalse
One morning, as Gregor Samsa was waking up from anxious dreams, he discovered
that in his bed he had been changed into a monstrous verminous bug. He lay on
his armour-hard back and saw, as he lifted his head up a little, his brown,
arched abdomen divided up into rigid bow-like sections.
\fi

Of course, this has to align with other syntactical TeX structures in you document whereas you can use % much more freely. The good news is that you can introduce your own switch to make this optional:

\newif\ifdraft
\drafttrue % or \draftfalse

\ifdraft
<only shown in draft mode>
\else 
<only shown in non-draft mode>
\fi

The \else part is optional and you could use \ifdraft ... \fi if you don’t need it.

Answer 3 (score 98)

The verbatim package provides a comment environment:

\documentclass{article}
\\usepackage{verbatim}
\begin{document}
    This text will be displayed
\begin{comment}
    This text will not be displayed.
\end{comment}
\end{document}

The Not So Short Introduction to LaTeX2e mentions this option on page 6 and remarks: “Note that this won’t work inside complex environments, like math for example.”

Question

I need to display the symbol ‘^’

d <- dist(fascores, method = "euclidean")^2

How do I do that?

Answer accepted (score 277)

You can use

• in text-mode (needs \textrm or similar in math-mode)

  • \textasciicircum or
  • \^{},

• in math-mode

  • \hat{} (only this produces a circumflex),
  • \widehat{}, or
  • \wedge (∧).

• in a verb-like manner

  • \string^,
  • \char^,</li> <li><p>`:

    \verb!d <- dist(fascores, method = "euclidean")^2!

Overview

Code

\documentclass{standalone}
\\usepackage{upquote}% getting the right grave ` (and not ‘)!
\begin{document}
\begin{tabular}{lcc}
    Input                   &       Text       &                 Math                  \\ \hline
    \verb|\string^|         &     \string^     &              $\string^$               \\
    \verb|\char`\^|         &     \char`\^     &              $\char`\^$               \\
    \verb|\verb!^!|         &     \verb!^!     &              $\verb!^!$               \\ \hline
    \verb|\textasciicircum| & \textasciicircum &                  ---                  \\
    \verb|\^{}|             & \^{} (e.g. \^a)  &                  ---                  \\ \hline
    \verb|\hat{}|           &       ---        &       $\hat{}$ (e.g. $\hat a$)        \\
    \verb|\wedge|           &       ---        &      $\wedge$ (e.g. $a\wedge b$)      \\
    \verb|\widehat{}|       &       ---        & $\widehat{\ }$ (e.g. $\widehat{abc}$) \\
\end{tabular}
\end{document}

Output

Answer 2 (score 4)

You could also try \textsuperscript{$\wedge$} which yields:

To put this into context, (\textsuperscript{$\wedge$}N225), will yield:

Question

I have some text in a table and I want to add a forced line break. I want to insert a forced line break without having to specify the column width, i.e. something like the following:

\begin{tabular}{|c|c|c|}
\hline
Foo bar & Foo <forced line break here> bar & Foo bar \\
\hline
\end{tabular}

I know that \\ inserts a line break in most cases, but here it starts a new table row instead.

A similar question was asked before: How to break a line in a table

Answer accepted (score 361)

Strangely, no answer (unless I’ve misread them) mentions a package that is dedicated to this precise question: makecell, which allows for common formatting of certain cells, thanks to its \thead and \makecell commands, and for line breaks inside these cells. The horizontal and vertical alignments can chosen independently from those of the table they’re included in. The default is cc, but you can change it globally in the preamble with

\renewcommand{\cellalign/theadalign}{vh}

where v is one of t,c,b and h one of l,c,r. Alternatively, for a single cell, you can use the \makecell or \thead commands with the optional argument [vh].

So here is a demo:

\documentclass[12pt]{article}
\\usepackage[utf8]{inputenc}
\\usepackage{fourier} 
\\usepackage{array}
\\usepackage{makecell}

\renewcommand\theadalign{bc}
\renewcommand\theadfont{\bfseries}
\renewcommand\theadgape{\Gape[4pt]}
\renewcommand\cellgape{\Gape[4pt]}

\begin{document}

  \begin{center}
    \begin{tabular}{ | c | c | c |}
      \hline
      \thead{A Head} & \thead{A Second \\ Head} & \thead{A Third \\ Head} \\
      \hline
      Some text &  \makecell{Some really \\ longer text}  & Text text text  \\
      \hline
    \end{tabular}
  \end{center}

\end{document} 

Answer 2 (score 382)

It’s a quite old question, but I’ll add my answer anyway, as the method I suggest didn’t appear in the others

\begin{tabular}{|c|c|c|}
\hline
Foo bar & \begin{tabular}[x]{@{}c@{}}Foo\\bar\end{tabular} & Foo bar \\
\hline
\end{tabular}

where x is either t, c, or b to force the desired vertical alignment.

In case this is needed in more than a couple of places, it’s better to define a command

\newcommand{\specialcell}[2][c]{%
  \begin{tabular}[#1]{@{}c@{}}#2\end{tabular}}

so the table line before can be one of

Foo bar & \specialcell{Foo\\bar} & Foo bar \\    % vertically centered
Foo bar & \specialcell[t]{Foo\\bar} & Foo bar \\ % aligned with top rule
Foo bar & \specialcell[b]{Foo\\bar} & Foo bar \\ % aligned with bottom rule

More variations are possible, for instance specifying also the horizontal alignment in the special cell.

Notice the @{} to suppress added space before and after the cell text.

Answer 3 (score 215)

It really is no wonder why LaTeX is said to be complicated! Just look at your answers to such an easy question! How about an easy solution to an every day problem?

\\usepackage{pbox}

\begin{tabular}{|l|l|} \hline
    \pbox{20cm}{This is the first \\ cell} & second \\ \hline
    3rd & and the last cell \\ \hline
\end{tabular}

which looks like:

Note that the width supplied to \pbox is a maximum width. If the content is shorter the length of the longest line is taken.

Question

I have an equation contained inside \[...\], which automatically makes a \sum with sub- and superscripts turn big–so that the summation sign looks awkward inside parenthesis. Any idea how to make the parenthesis completely enclose the whole summation?

\documentclass{article}
\begin{document}
We have:
\[ \sum_{i=1}^n i = (\sum_{i=1}^{n-1} i) + n =
\frac{(n-1)(n)}{2} + n = \frac{n(n+1)}{2} \]
\end{document}

Answer accepted (score 241)

The usual thing to do is replace ( with \left( and ) with \right), which automatically expand to fit the material between them. Note that every \left... requires a \right... (but the type of bracket may be different, i.e. \left(...\right] also works).

I would typeset your equation as

\begin{equation*}
\sum_{i=1}^n i = \left(\sum_{i=1}^{n-1} i\right) + n =
\frac{(n-1)(n)}{2} + n = \frac{n(n+1)}{2}
\end{equation*}

For manual control of sizes (most of the time you won’t need these)

( \big( \Big( \bigg( \Bigg(

produce

Answer 2 (score 49)

Automatically sized parentheses are obtained with \left and \right, as any LaTeX guide or manual tells.

However, automatic sizing is not good in every case; one of these cases is precisely that of summations with limits above and below: compare the results of

\[
\left( \sum_{i=1}^{n-1} i \right)\biggl(\sum_{i=1}^{n-1} i\biggr)
\]

(the font is that obtained with \\usepackage{fouriernc}). In general the second way is to be preferred.

Answer 3 (score 34)

One way is using \left and \right, followed by the parenthesis you want to use. These are mostly () [] {} \langle\rangle and |. You can also use a . to have no parenthesis displayed, e.g. when you want an opening, but no closing one.

\left( \frac12 \right)
\quad
\left\langle \frac23 \right.
\quad
\left\{ \frac34 \right]

creates

If you want to control the size manually, use (in ascending order) , , , .

( \frac12 \big)
\quad
\Bigg\langle \frac23 \big]
\quad
\Big\{ \frac34 \Bigg.

results in

Question

I’m new to LaTeX, investigating using it for some work projects. I’m using MiKTeX on Windows. My employer’s locked-down network blocks the application’s automatic installation function. I can take my laptop home and successfully install from there, but if I need a package in the middle of the day I’m stuck.

I am able to access the CTAN website and download the package files (.dtx or .ins?), but I don’t know what do do with them. How can I do a manual package installation?

Answer accepted (score 169)

Firstly, check README files, available documentation of the package, perhaps the beginning of the .dtx file to get installation information.

Installing a package available as dtx/ins bundle:

• Download the content of the package directory. dtx is the extension of a documented source file, ins is the extension of an installation file. Put this in a temporary directory.

• If there’s nothing differently written in a README file run LaTeX (or TeX) on the .ins file. This is best done using the command prompt (latex packagename.ins), but you may use your TeX editor in LaTeX/DVI-LaTeX mode or what it is called there. This would usually produce one or more files ending with .sty, perhaps some additional files. As you now have cls or sty files or the like, the remaining steps are the same like in the next alternative way:

Installing sty or cls files:

• Create a new directory with the package name in your local texmf directory structure, see also Create a local texmf tree in MiKTeX. Why not to choose the main MiKTeX texmf tree see in Purpose of local texmf trees.

• Copy the package files (*.sty, *.cls etc.) into this directory.

• Make the new package known to MiKTeX: refresh the MiKTeX filename database. To do this, click “Start/ Programs/ MiKTeX 2.x/ Maintenance/ Settings” (or similar) to get to the MiKTeX options, click the button “Refresh FNDB”. The installation is complete.

• If you did not download the documentation already, you could get it by running pdfLaTeX or LaTeX on the .dtx file. Compile twice to get correct references.

Obtaining and installing packaged universal archives:

Perhaps you could get a file with the extension .tds.zip. Such files are archives fitting to your TeX directory structure. Open it, check the content structure. You could extract it to the right place. Also here, as after any installation, refresh the MiKTeX filename database.

Installing a font package

Installing a font package, especially for Type1 fonts, requires additonal steps. See Manual font installation.

Links with further information:

• Integrating Local Additions on MiKTeX.org

• What are documented LaTeX sources (.dtx files) in the UK TeX FAQ

• Installing things on a (La)TeX system with detailed general instructions in the UK TeX FAQ

• Downloading and Installing Packages by Nicola L. C. Talbot

• The dtx format by Joseph Wright

A different and very effective way, using a local repository:

^{(works only for all in the MiKTeX package repository available packages)}

• Use the MiKTeX net installer to download the complete MiKTeX repository to a USB drive.

• On a MiKTeX system, choose this directory as the local package repository in the package manager.

• Use this local repository for installation and updates.

• You may update that local repository later using the net installer: it loads the database from the server, compares and downloads new or updated packages.

Answer 2 (score 34)

You can set up a local packages repository on your computer.

You need an internet access to download the MikTex packages.

My problem is that I can’t succeed in setting up the internet proxy setup of MikTex in my system, so I have tried today the following solution with MikTex 2.9 and it worked with no problems; the on-the-fly package installation worked well too.

1. Create the folder, for example c:\miktex_pkgs

2. Copy the following file to the folder c:\miktex_pkgs (If you do not copy the files you will probably get some errors from MikTex. See http://bruceyf.wordpress.com/2008/05/07/miktexs-secret-local-package-repository/ for the details):

   http://mirrors.ctan.org/systems/win32/miktex/tm/packages/README.TXT

   http://mirrors.ctan.org/systems/win32/miktex/tm/packages/miktex-zzdb1-2.9.tar.lzma

   http://mirrors.ctan.org/systems/win32/miktex/tm/packages/miktex-zzdb2-2.9.tar.lzma

3. You can copy any packages you may need from http://www.ctan.org/tex-archive/systems/win32/miktex/tm/packages to your local folder c:\miktex_pkgs

4. At this point you have two options.

   • Update your MikTex system: from the Windows Start menu -> Programs -> Miktex 2.9 -> Maintenance (Admin) -> launch the program “Settings (Admin)”

     Go to the tab “Package repository” and choose the folder c:\miktex_pkgs

     Install packages…

   • Open a command prompt and navigate to c:\miktex_pkgs

     Use mpm.exe --install {name} to install packages. The {name} does not include any of the extensions (.cab, .tar.lzma, .tar.bz2, etc.).

Answer 3 (score 4)

Have you tried to log into your admin account and then - using the shortcuts in the start menu - to go to the package-manager? There you can manually search for the packages which you access using the \\usepackage-command and install them by simply clicking onto the plus on the top left. Important note: Always open the package manager using a right click and choose “Open as admin”.

For me this always works out…

Question

I have a long equation but long enough to occupy two lines. I want to break it to improve readability. How can I break it?

\begin{equation}
F = \{F_{x} \in  F_{c} : (|S| > |C|) \cap 
(minPixels  < |S| < maxPixels) \cap 
(|S_{conected}| > |S| - \epsilon)
  \}
\end{equation}

I wan to break it in 3 lines after \cap. But \\ or \n didn’t work

Answer accepted (score 181)

Use split environment provided by amsmath package.

\begin{equation}
\begin{split}
F = \{F_{x} \in  F_{c} &: (|S| > |C|) \\
 &\quad \cap (\text{minPixels}  < |S| < \text{maxPixels}) \\
 &\quad \cap (|S_{\text{conected}}| > |S| - \epsilon) \}
\end{split}
\end{equation}

Answer 2 (score 35)

For simple multi-line equations without alignment, use the multline environment:

\begin{multline}
F = \{F_{x} \in  F_{c} : (|S| > |C|) \cap 
(minPixels  < |S| < maxPixels) \\ \cap 
(|S_{conected}| > |S| - \epsilon)
  \}
\end{multline}

Answer 3 (score 33)

The aligned environment from amsmath is also a good option:

\begin{equation}
\begin{aligned}
F ={} & \{F_{x} \in  F_{c} : (|S| > |C|) \\
      & \cap (\mathrm{minPixels}  < |S| < \mathrm{maxPixels}) \\
      & \cap (|S_{\mathrm{conected}}| > |S| - \epsilon)\}
\end{aligned}
\end{equation}

Question

In LaTeX, % can be used for single-line comments. For multi-line comments, the following command is available in the verbatim package.

\begin{comment}
Commented code
\end{comment}

But is there a simple command like /* code */ in C?

Answer 2 (score 151)

Following the C code paradigm, where one can use the preprocessor directives

#if 0
junk code
#endif

something similar can be done in TeX (and descendants):

\iffalse
I don't want this to happen
\fi

The commented parts can be easily activated by replacing \iffalse with \iftrue.

Answer 3 (score 50)

No, but you can define something close:

\documentclass{article}
\begin{document}
\long\def\/*#1*/{}

AAA

\/* This is a test
    and this is another
*/

BBB
\end{document}

Question

How can I produce the text Word_one_two in LaTeX?

I tried:

Samp\_Dist\_Corr

But, it doesn’t quite look right. Also, I want it in the typewriter font, so actually, I’m doing:

\texttt{Samp\_Dist\_Corr}

I find it looks a bit like the underscore is merging in to the bottom of the “D”, but maybe it’s just because of the typewriter D?

Answer accepted (score 145)

You may prefer the character from the tt font:

\documentclass{article}

\begin{document}

\texttt{Samp\_Dist\_Corr}

\verb|Samp_Dist_Corr|

\texttt{Samp\char`_Dist\char`_Corr}

\end{document}

Or probably better add \\usepackage[T1]{fontenc} then all the above forms will use the character from the font.

Answer 2 (score 70)

You can use \textunderscore also.

\documentclass{article}
%
\begin{document}
Samp\textunderscore Distt\textunderscore Corr

\texttt{Samp\textunderscore Distt\textunderscore Corr}
\end{document}

Underscore is not merging at the bottom of D actually. It is very close to it.

Answer 3 (score 60)

A fairly elementary way of stripping special meaning from things is to \detokenize them:

\documentclass{article}
\begin{document}
\texttt{\detokenize{Samp_Dist_Corr}}

\texttt{\detokenize{a@b\c_d&e~f g}}
\end{document}

Note how a space is inserted after a “control sequence”. See What are the exact semantics of \detokenize?

Question

There are two different commands to incorporate another file into the source of some document, \input and \include. When should I use one or the other? What are the differences between them? Are there more things like them to be aware of?

Answer accepted (score 949)

\input{filename} imports the commands from filename.tex into the target file; it’s equivalent to typing all the commands from filename.tex right into the current file where the \input line is.

\include{filename} essentially does a \clearpage before and after \input{filename}, together with some magic to switch to another .aux file, and omits the inclusion at all if you have an \includeonly without the filename in the argument. This is primarily useful when you have a big project on a slow computer; changing one of the include targets won’t force you to regenerate the outputs of all the rest.

\include{filename} gets you the speed bonus, but it also can’t be nested, can’t appear in the preamble, and forces page breaks around the included text.

Answer 2 (score 336)

Short answer:

\input is a more lower level macro which simply inputs the content of the given file like it was copy&pasted there manually. \include handles the file content as a logical unit of its own (like e.g. a chapter) and enables you to only include specific files using \includeonly{filename,filename2,...} to save times.

Long answer:

The \input{<filename>} macro makes LaTeX to process the content of the given file basically the same way as if it would be written at the same place as \input. The LaTeX version of \input only does some sanity checks and then uses the TeX \input primitive which got renamed to \@@input by LaTeX.

Mentionable properties of \input are:

• You can use \input basically everywhere with any content.
  It is usable in the preamble, inside packages and in the document.
• You can nest \input macros.
  You can use \input inside a file which is read using \input.
• The only thing \input does is to input the file.
  You don’t have to worry about any side effects, but don’t get any extra features.

The \include{<filename>} macro is bigger and is supposed to be used with bigger amounts of content, like chapters, which people might like to compile on their own during the editing process.

\include does basically the following thing:

• It uses \clearpage before and after the content of the file. This ensure that its content starts on a new page of its own and is not placed together with earlier or later text.
• It opens a new .aux file for the given file.
  There will be a filename.aux file which contains all counter values, like page and chapter numbers etc., at the begin of the filename. This way the file can be compiled alone but still has the correct page and chapter etc. numbers. Such part aux files are read by the main aux file.
• It then uses \input internally to read the file’s content.

Mentionable properties of \include are:

• It can’t be used anywhere except in the document and only where a page break is allowed.
  Because of the \clearpage and the own .aux file \include doesn’t work in the preamble, inside packages. Using it in restricted modes or math mode won’t work properly, while \input is fine there.
• You can’t nest \include files.
  You can’t use \include inside a file which is read by \include. This is by intention and is because to avoid issues with the .aux files. Otherwise three .aux files (main, parent \include, child \include) would be open at the same time which was deemed to complicated I guess.
  You can use \input inside an \include file and also \input an \include file.
• Biggest benefit: You can use \includeonly{filename1,filename2,...} in the preamble to only include specific \include files.
  Because the state of the document (i.e. above mentioned counter values) was stored in an own .aux file all page and sectioning numbers will still be correct. This is very useful in the writing process of a large document because it allows you to only compile the chapter you currently write on while skipping the others. Also, if used persistently it can be used to create PDFs of sub-parts of your document, like only the front matter or everything but/only the appendix, etc.
  There is also the excludeonly package which provides an \excludeonly to exclude only certain files instead of including all other files.

Answer 3 (score 99)

\input effectively replaces the command with the contents of the input file. \input’s can be nested. So, you can write:

\documentclass{article}

\begin{document}

AAA

\input{b}

AAA

\end{document}

where b.tex is:

BBB

\input{c}

BBB

and c.tex is:

CCC

to get output like:

AAA
BBB
CCC
BBB
AAA

include triggers a newpage both before and after the included material, rather as though you’d used an \input flanked by \clearpage commands. include also supports the \includeonly mechanism. So, the file:

\documentclass{article}

\includeonly{c}

\begin{document}

AAA

\include{b}

\include{c}

AAA 

\end{document}

with b.tex and c.tex as before, will produce output with AAA on page one, CCC on page two, and AAA on page 3.

The \include and \includeonly pair is very useful for working on long documents: you can \includeonly the file which you are editing, and compilation is much faster. If you do two runs on the full file before using \includeonly, page numbers and cross-references will remain valid for the quicker \includeonly compilation.

Question

I am writing a thesis report using LaTeX and I need to add indentations because every new paragraph starts from the initial position on the left.

How do I add indentations?

Answer accepted (score 59)

Paragraph indention is controled by the parameter \parindent. In most document classes it is set to a positive value so you should see indentations. If this is not the case you can set this parameter in the document preamble to whatever value you wish, e.g.

\setlength\parindent{24pt}

Of course, a requirement is that you mark up your paragraphs: a paragraph ends by either a blank line or by the command \par. If you instead just used \\you have directed LaTeX to start a new line but not a new paragraph.

Answer 2 (score 47)

I think you need:

\indent Here comes your text

Answer 3 (score 17)

To forcibly insert a space that is the same length as an indentation you can use the following:

\hspace{\parindent}

This can be useful if you start a new section with a framed theorem, etc., and latex does not recognize it as a paragraph.

Question

I have used the \hrulefill command to create a horizontal rule, along with some other commands. In each case I have the rules extended up to the margin.

I want the rule width to be controllable, i.e. I want them to span the entire page. How can this be done? The existing help on Internet looks pretty scarce. Thanks for your help.

Answer 2 (score 189)

To get horizontal lines of any fixed length you can use the \rule command. To get a horizontal line spanning the whole page width you can use a \makebox command and then a \rule with a width equal to \paperwidth:

\documentclass{article}

\begin{document}

Below is a Line spanning the entire width of the page

\noindent\makebox[\linewidth]{\rule{\paperwidth}{0.4pt}}

Below is a 2cm long line

\noindent\rule{2cm}{0.4pt}

Below is a 4cm long line

\noindent\rule{4cm}{0.4pt}

Below is a 8cm long line

\noindent\rule{8cm}{0.4pt}

\end{document}

Output: Rules in LaTeX are 0.4pt “thick”, by default.

Answer 3 (score 102)

Another option is this one, which makes a horizontal line stretch the entire page. I prefer this one, because it’s short, easy to remember and exactly what I need. I hope this works for you too.

\noindent\rule{\textwidth}{1pt}

Question

I’ve seen documentation whereby an \alph command is put around the \begin{enumerate} somewhere, but I’m not entirely sure how that operates…

Answer accepted (score 244)

Without any package you could do it by redefining the command \theenumi for formatting the enumi counter. (Also enumii, etc., for nested lists.)

\renewcommand{\theenumi}{\Alph{enumi}}

inside the environment…. Or better, you could use a package like enumitem which allows, e.g.,

\\usepackage{enumitem}
...
\begin{enumerate}[label=\Alph*]
\item this is item a
\item another item
\end{enumerate}

Use \alph for lowercase letters, \Alph for uppercase, etc. See the package documentation for more info.

Answer 2 (score 236)

Use the package enumitem.

\\usepackage[shortlabels]{enumitem}
.
.
.
\begin{enumerate}[(a)] % (a), (b), (c), ...
\item
\end{enumerate}
.
.
.
\begin{enumerate}[a)] % a), b), c), ...
\item
\end{enumerate}

Answer 3 (score 42)

With enumitem package, we can do as follow:

Preamble:

\\usepackage{enumitem}
\newcommand{\subscript}[2]{$#1 _ #2$}

In document use:

\begin{enumerate}[label=(\subscript{E}{{\arabic*}})]
    \item
    Generated by the $f*\tilde{g}$, where $f\in C_c(G)$, $g\in C_c(G)$;
    \item
    Generated by the $h*\tilde{h}$, where $h\in C_c(G)$;
\end{enumerate}

Question

It’s easy to make subscripts in math mode: $a_i$.

How do I make a subscript outside math environment, like_this?

Answer 2 (score 137)

Note that \textsubscript enters math mode as well. This might produce problems in PDF strings where math is not allowed, for instance in bookmarks. If you used hyperref and simply used \textsubscript in a section heading, hyperref would complain about the math shift. The command \texorpdfstring comes to the rescue:

\documentclass{article}
\\usepackage{fixltx2e}
\\usepackage{hyperref}
\begin{document}
\section{\texorpdfstring{like\textsubscript{this}}{like this}}
\end{document}

That applies to math and math symbols in sectioning headings of course as well.

Since 2015, LaTeX provides the fixltx2e features by default, so you can omit \\usepackage{fixltx2e}then.

Answer 3 (score 102)

This is included in the fixltx2e package:

\documentclass{article}
\\usepackage{fixltx2e}

\begin{document}
like\textsubscript{this}
\end{document}

Interestingly (?), there’s a \textsuperscript command already in LaTeX.

This is included already in the KOMA-Script bundle. If you want to typeset chemical formulas, have a look at the mchem package.

(Thanks to Caramdir for those last two.)

Question

Some of the available classes of documents in LaTeX are well known and widely used, such as the article and beamer classes, while others are not so well known, such as the standalone class.

I found this figure (edit: transcribed)

article for articles in scientific journals, presentations, short reports, program documentation, invitations, …
proc a class for proceedings based on the article class.
minimal is as small as it can get. It only sets a page size and a base font. It is mainly used for debugging purposes.
report for longer reports containing several chapters, small books, thesis, …
book for real books
slides for slides. The class uses big sans serif letters.
memoir for changing sensibly the output of the document. It is based on the book class, but you can create any kind of document with it (1)
letter For writing letters.
beamer For writing presentations (see LaTeX/Presentations).

which lists the main classes and is a good starting point, but the description is too short and still leaves one wondering when it would be more suitable to choose one class over the other and what the characteristics of each class is. Furthermore, the list is not exhaustive I think, given that I know at least one more document class that is not there (the standalone class, as I mentioned).

So my question is: what are the available classes of documents in LaTeX, and could you provide a brief description of the class and the situations where it would be recommended?

Please give only one class per answer.

Answer 2 (score 142)

New working link: Al­ter­na­tive LaTeX class(es)

Original answer:

There’s a category in the TeX Catalogue: Alternative Document Classes (web archive link).

Answer 3 (score 95)

The classes in the KOMA-Script bundle* (scrbook, scrreprt, scrartcl, scrlttr2) provide replacements of standard classes (book, report, article and letter respectively). They offer lots of configuration options to accommodate different layouts without using ugly hacks. Generally I think they are nearer to European (and in particular German) typography conventions than the standard classes are.

• see also the german homepage of KOMA-Script.

Question

I have a document which requires many levels of sectioning. I have sections, subsections and subsubsections, but require one more level below that. I can’t change the sections to be parts and move everything up a level, as this document will eventually be included in another document which has parts/chapters already.

I see that the \paragraph command is used for defining the section level below subsubsection, but that doesn’t produce headings in the same way that subsection and subsubsection do. Is there any way to either (1) change the \paragraph command so that it works like subsubsection but just adds another number - ie. 1.2.3.4 or (2) create a \subsubsubsection command to do the same thing?

Answer accepted (score 209)

You can use the titlesec package to change the way \paragraph formats the titles and set the secnumdepth counter to four to obtain numbering for the paragraphs:

\documentclass{article}
\\usepackage{titlesec}

\setcounter{secnumdepth}{4}

\titleformat{\paragraph}
{\normalfont\normalsize\bfseries}{\theparagraph}{1em}{}
\titlespacing*{\paragraph}
{0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}

\begin{document}

\section{Test Section}
test
\subsection{Test Subsection}
test
\subsubsection{Test Subsubsection}
test
\paragraph{Test Modified Paragraph}
test

\end{document}

If you want to define a new sectioning command, you can take a look at Defining custom sectioning commands.

If you want to define a fresh new sectional unit below \subsubsection, but above \paragraph, then you will have to do considerably more work: a new counter has to be created and its representation has to be appropriately defined; the sectional units \paragraph and \subparagraph will also have to be redefined, as well as they corresponding \l@... commands (controlling how the will be typeset in the ToC if the tocdepth value is increased); also, the toclevel (for eventual bookmarks) will have to be considered.

Here’s an example showing how to obtain this new sectional unit giving you now the option to use \part, \section, \subsection, \subsubsection, \subsubsubsection, \paragraph, and \subparagraph:

\documentclass{article}
\\usepackage{titlesec}
\\usepackage{hyperref}

\titleclass{\subsubsubsection}{straight}[\subsection]

\newcounter{subsubsubsection}[subsubsection]
\renewcommand\thesubsubsubsection{\thesubsubsection.\arabic{subsubsubsection}}
\renewcommand\theparagraph{\thesubsubsubsection.\arabic{paragraph}} % optional; useful if paragraphs are to be numbered

\titleformat{\subsubsubsection}
  {\normalfont\normalsize\bfseries}{\thesubsubsubsection}{1em}{}
\titlespacing*{\subsubsubsection}
{0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}

\makeatletter
\renewcommand\paragraph{\@startsection{paragraph}{5}{\z@}%
  {3.25ex \@plus1ex \@minus.2ex}%
  {-1em}%
  {\normalfont\normalsize\bfseries}}
\renewcommand\subparagraph{\@startsection{subparagraph}{6}{\parindent}%
  {3.25ex \@plus1ex \@minus .2ex}%
  {-1em}%
  {\normalfont\normalsize\bfseries}}
\def\toclevel@subsubsubsection{4}
\def\toclevel@paragraph{5}
\def\toclevel@paragraph{6}
\def\l@subsubsubsection{\@dottedtocline{4}{7em}{4em}}
\def\l@paragraph{\@dottedtocline{5}{10em}{5em}}
\def\l@subparagraph{\@dottedtocline{6}{14em}{6em}}
\makeatother

\setcounter{secnumdepth}{4}
\setcounter{tocdepth}{4}

\begin{document}

\tableofcontents
\section{Test Section}
test
\subsection{Test Subsection}
test
\subsubsection{Test Subsubsection}
test
\subsubsubsection{Test Subsubsubsection}
test
\paragraph{Test Paragraph}
test
\subparagraph{Test Subparagraph}
test

\end{document}

Answer 2 (score 67)

Here’s a solution that doesn’t require the use of a specialized package such as titlesec or sectsty. (There’s nothing wrong per se, obviously, with using packages to achieve a certain goal; nevertheless, I think it can be instructive at times to see how one can manipulate some of LaTeX’s built-in commands directly.)

If you use the article document class, the default appearance of the output of the commands \subsubsection and \paragraph is set up as follows:

\newcommand\subsubsection{\@startsection{subsubsection}{3}{\z@}%
                {-3.25ex\@plus -1ex \@minus -.2ex}%
                {1.5ex \@plus .2ex}%
                {\normalfont\normalsize\bfseries}}
\newcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
                {3.25ex \@plus1ex \@minus.2ex}%
                {-1em}%
                {\normalfont\normalsize\bfseries}}

To make the \paragraph command behave more like the \subsubsection command, but with less vertical spacing above and below the sectioning header line(s), you could modify the \paragraph command to make its output behave as if it were a “subsubsubsection”. The following MWE illustrates a possible setup.

\documentclass{article}
\makeatletter
\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
            {-2.5ex\@plus -1ex \@minus -.25ex}%
            {1.25ex \@plus .25ex}%
            {\normalfont\normalsize\bfseries}}
\makeatother
\setcounter{secnumdepth}{4} % how many sectioning levels to assign numbers to
\setcounter{tocdepth}{4}    % how many sectioning levels to show in ToC

\begin{document}
\tableofcontents
\section{A}
\subsection{B}
\subsubsection{C1}
\paragraph{D1}
\paragraph{D2}
\subsubsection{C2}
\end{document}

Answer 3 (score 7)

The are two good answers to show how to add a new level section or modify an existing one. But both are assuming some basic knowledge of LaTeX and typography. Maybe these remarks can help to new users to decide when these or a similar approaches are the best solution.

requires many levels of sectioning

The best solution could be reconsider that premise. Is it really true? Sometimes (e.g., legal documents, huge technical reports), but often is not an imperative requirement but the insane decision of mimic this or that monstrous thesis. Defaults levels are more than enough in most documents.

I have sections, subsections and subsubsections …

I see that the \paragraph command is used …

It seems that you are using the article class, because you mention only this four heading levels, so the first question is
How many levels of nested subsections can the article class support? Short anwser: there are six, not four levels of sectioning.

Moreover, the book-like classes than allow one more level (\chapter), so you can have at least seven levels (-1 to 5, not 1 to 7) without effort. Using the memoir class you have also the option that chapters behave as sections:

\documentclass[article,oneside]{memoir}
\setcounter{secnumdepth}{5} % Note that part is -1 level !
\setcounter{tocdepth}{5}
\begin{document}
\begingroup
\let\clearpage\relax
\let\newpage\relax
\tableofcontents*
\part{Part}
\endgroup
\chapter{Chapter} Text. 
\section{Section} Text.
\subsection{Subsection} Text.
\subsubsection{Subsubsection} Text.
\paragraph{Paragraph} Text.
\subparagraph{Subparagraph} Text.
\end{document}

Need more? For a deeper structuring of your contents you can use also the starred versions of sectioning commands (\subsection*, etc.), environment lists (enumerate, itemize,description, or a custom list) and a judicious use of blank lines (\par) to remark the content structure (often some people break paragraphs only to avoid long chunks of texts).

Still need More section headings? Well, it’s up to you. Then go to other answers, or follow the last link for a ridiculously high number of sectional levels.

Question

I have the following table:

\begin{table}[htb]
\begin{tikzpicture}
\node (table) [inner sep=0pt] {
\begin{tabular}{ l | l }
  {\bf Symptom} & {\bf Metric} \\
\hline
Class that has many accessor methods and accesses a lot of external data & ATFD is more than a few\\
Class that is large and complex & WMC is high\\
Class that has a lot of methods that only operate on a proper subset of the instance variable set & TCC is low\\
\end{tabular}
};
\draw [rounded corners=.5em] (table.north west) rectangle (table.south east);
\end{tikzpicture}
\caption{God class symptoms}
\label{tbl:god_class}
\end{table}

Now I want to force the width of the table to be the same as the \textwidth, either by linewrapping of table text or by scaling. How can I achieve that?

Answer accepted (score 170)

You can use the tabularx package. It allows you to set the width of the table and provides the X column type, which fills out the rest of the space. It can be used for several columns, which then share the rest of the width equally.

Example:

\\usepackage{tabularx} % in the preamble
% ....
\begin{tabularx}{\textwidth}{X|l}
  \textbf{Symptom} & \textbf{Metric} \\
\hline
Class that has many accessor methods and accesses a lot of external data & ATFD is more than a few\\
Class that is large and complex & WMC is high\\
Class that has a lot of methods that only operate on a proper subset of the instance variable set & TCC is low\\
\end{tabularx}

In general it is also possible to set the width of a column using p{<width>} instead of l as column type. Then it will be formatted as a paragraph and can include line breaks. Replace <width> with the required width.

Answer 2 (score 123)

Just to mention an additional method: the tabular* environment. Suppose you have a table with 6 center-aligned columns. You can force it to take up the full width of the textblock by setting it up as follows:

\begin{tabular*}{\textwidth}{c @{\extracolsep{\fill}} ccccc}
...
\end{tabular*}

Unlike the tabularx and tabulary environments, which work by expanding the width of the columns, the tabular* environment works by expanding the intercolumn whitespace.

Personally, I suspect it’s the need to remember to insert the directive @{\extracolsep{\fill}} that has kept the popularity of this approach quite subdued…

Answer 3 (score 22)

One can use tabu (e.g). It will set the table to a given width without needing to calc the ration by hand.

\documentclass{article}

\\usepackage{tabu}
\\usepackage{booktabs}% for better rules in the table

\begin{document}
\begin{tabu} to \textwidth {XXXX}
   \toprule
   xx & 1 & 2 & 3 \\
   \bottomrule
\end{tabu}
\end{document}

tabu comes with the new column type X which sets its width automatically. It has an optional argument taking l, r, c to adjust the alignment inside the cell or a numer to set uneven widths of columns. For example two columns, the first on right, the second one left aligned and twice the width of the first one, will be X[r]X[2] (l and 1 will be set by default). The part between to and {<cols>} can be any width, and the full part can be omitted to, i.e. \begin{tabu}{<cols>}.

tabu is compatible with longtable with the new environment {longtabu}.

Adding showframeand some text (lipsum) to the above example shows that the table has exactly the width of the text. On may notice that a table without a float environment is set inline and gets indented as every normal text, too. Use \noindent to prevent that.

\documentclass{article}

\\usepackage{tabu}
\\usepackage{booktabs}% for better rules in the table
\\usepackage{showframe,lipsum}

\begin{document}
\lipsum[4]

\noindent
\begin{tabu} to \textwidth {XXXX}
   \toprule
   xx & 1 & 2 & 3 \\
   \bottomrule
\end{tabu}
\end{document}

Question

I’m using bibtex for my bibliography in LaTeX. I have some URL’s I need to cite in the paper. How do I add URLs into the .bib file?

A typical section in my .bib file looks like this:

@conference{eigenfacepaper,
  title={{Face recognition using eigenfaces}},
  author={Turk, M. and Pentland, A.},
  booktitle={Proc. IEEE Conf. on Computer Vision and Pattern Recognition},
  volume={591},
  year={1991}
}

I tried some misc sections in bibtex but they don’t show up in my document.

Answer accepted (score 274)

The last time I cited an URL, I used a BibTeX entry of the following form:

@misc{bworld,
  author = {Ingo Lütkebohle},
  title = {{BWorld Robot Control Software}},
  howpublished = "\\url{http://aiweb.techfak.uni-bielefeld.de/content/bworld-robot-control-software/}",
  year = {2008}, 
  note = "[Online; accessed 19-July-2008]"
}

If that does not show up, then it might indeed be a problem with your BibTeX style (or you forgot to \\usepackage{url} or \\usepackage{hyperref} in your main .tex file).

Answer 2 (score 60)

You need to

 \\usepackage{url}

and then

 howpublished={\\url{http://my.url.com/}},

Answer 3 (score 35)

Depends what BibTeX style you’re using. In the ordinary ones I usually use

note={\\url{http://...}}

in biblatex (and natbib too, I think), you can just write

url={http://...}

Question

How to write in bibliography (package natbib) letter “a” with two dots above? Specially, I mean the word Birkhäuser.

Is there a general rule or way how to write such umlauts or other accented letters in bibliographies?

Answer accepted (score 445)

To typeset accented characters inside bibliography fields for processing with BibTeX, encase them in curly braces. To list but a few accented characters:

{\"a} {\^e} {\`i} {\.I} {\o} {\'u} {\aa} {\c c} {\\u g} {\l} {\~n} {\H o} {\v r} {\ss}

The word Birkhäuser should therefore be entered as Birkh{\"a}user.

Just to provide a somewhat more involved case: the name Jaromír Kovářík should be entered as either Jarom{\'i}r Kov{\'a}{\v r}{\'i}k or, more succinctly, Jarom{\'i}r Kov{\'a\v r\'i}k. As is explained in greater detail below, BibTeX will then sort the surname Kovářík as if it were spelled Kovarik, i.e., without any “accented characters”. Replacing the accented characters in Kovářík with unaccented characters matters if the bibliography’s entries are sorted alphabetically by authors’ surnames and if the bibliography contains entries with the surnames Kovářík, Kovács, Kowalski, and Kowatski…

Addendum: There is an obvious follow-up question to the “How does one enter a special character for use in BibTeX?” question: Why is it necessary to encase these “special characters” in this manner? Or: Why are the ordinary methods of entering these characters in a LaTeX document – say, \"{a} or \"a, let alone ä – not quite right for BibTeX?

There are two separate reasons for this requirement.

1. If you use double-quotes, i.e., " ... ", to delimit the contents of a bibliographic field, you will find that writing

   author = "Anna H\"{a}user",

   generates a BibTeX error, whereas

   author = "Anna H{\"a}user",

   does not. I.e., BibTeX isn’t quite smart enough on its own to distinguish between the two uses of the " character and needs extra help.

2. In addition, contents of bibliographic fields – certainly the author and editor fields, but potentially other fields as well, including the title, booktitle, and organization fields – are frequently used to sort entries alphabetically.

   How do BibTeX (and LaTeX) sort characters with Umlaute, diacritics, and other special features relative to the basic 26 characters of the Latin alphabet? How is one supposed to sort three authors named, say, Peter Hauser, Anna Häuser, and John Hill? For some pretty sound reasons – but which are way too ancient and obscure to go into any adequate level of detail here; to explore these reasons properly, it’s crucial to have Appendix C of the TeXBook handy… – a decision was made in the design of BibTeX to “purify” (the BibTeX function that does this job really is called purify$!) the contents of various fields as follows (this method conforms, probably not surprisingly, to US and UK sorting criteria; it needn’t be “correct” outside of English-speaking regions, as I will note below) for sorting purposes:

   • {\"a}, {\'a}, {\^a}, etc are all made equivalent to a,
   • {\"o}, {\'o}, {\H o} and {\o} are all made equivalent to o,
   • {\l} and {\L} become equivalent to l and L, respectively,
   • {\ss} becomes equivalent to ss,
   • {\aa} becomes equivalent to aa,
   • and so on for all other “accented” characters,
   • finally, any characters that do not fit into this scheme, including ä, are moved to the very end, i.e., after z. This may seem arbitrary and ill-informed from today’s vantage point, but back when BibTeX was created more than 20 years ago the only relevant character encoding and sorting system was ASCII.

   As you can immediately appreciate, this “purification” step is greatly simplified and made more robust if the “accented” characters are all entered consistently in the manner suggested in the first part of this answer.

   Turning to the earlier case of the three authors named Peter Hauser, Anna Häuser, and John Hill: How will they appear in a bibliography whose entries are sorted alphabetically by the authors’ surnames? If Anna’s last name is entered as H{\"a}user, the three authors will end up being listed as Häuser, A. - Hauser, P. - Hill, J.. In contrast, if Anna’s last name had been entered as Häuser, the sorting order would have been Hauser - Hill - Häuser. For most English-speaking readers, the second ordering will look completely wrong.

Some specialists from, say, Sweden, may object that this approach to sorting characters that aren’t among the basic 26 characters of the Latin alphabet doesn’t meet the specific national standards of, say, Sweden. [I obviously don’t mean to pick on any Swedes. I mention them because I remember having read somewhere that in the Swedish alphabet, ä does come after z and hence is definitely not equivalent (not even for sorting purposes!) to a.] My answer to this objection is: If you’re a Swedish author writing in Swedish for a Swedish target audience, you had better conform to specific Swedish customs. On the other hand, if you’re a Swede writing in English in a journal that’s exclusively published in English, it’ll do you no good at all if you try to insist on obeying Swedish sorting customs in your paper’s bibliography. Of course, the very inability of BibTeX to be easily adaptable to non-English sorting customs is one of the reasons for the development and adoption of BibLaTeX and Biber. However, that’s a topic for another day, isn’t it?

The issue of how BibTeX sorts bibliographic entries (as well as many other fascinating [!] issues) is examined at length and explained admirably in the surprisingly readable (given the enormous dryness of the subject!) essay Tame the BeaST by Nicolas Markey. If you have TeXLive or MikTeX as your TeX distribution, you can also access this document by typing “texdoc tamethebeast” at a command prompt.

For the sake of completeness and replicability, here’s the MWE that gives to the screenshot shown above. Note that it’s not necessary to load any extra packages to typeset the accented characters considered in this example. However, assuming you use pdfLaTeX to compile your document, you will need to load the fontenc package with the option T1 if you need to typeset, say, an ogonek-accented character, such as {\k a}, or the Icelandic “thorn”, {\th}.

\documentclass[border=1pt]{standalone}
\begin{document}
{\"a} {\^e} {\`i} {\.I} {\o} {\'u} {\aa} {\c c} {\\u g} {\l} {\~n} {\H o} {\v r} {\ss}
\end{document} 

Answer 2 (score 50)

When using \\usepackage[utf8]{inputenc} you can have it directly.

Consider the following .bib file:

@BOOK
  {Goe,
   AUTHOR  = "Gödel",
   TITLE   = "Die Vollständigkeit der Axiome des logischen Funktionenkalküls.",
   PUBLISHER = "Monatshefte für Mathematik und Physik",
   YEAR = 1930
  }

for example. Then

\documentclass{article}
\\usepackage[utf8]{inputenc}

\begin{document}
\bibliographystyle{plain}

\section{Introduction}
Hällo Wörld\cite{Goe}

\bibliography{encodingInBib}

\end{document}

yields the desired result. Or, you could also use biblatex and the following code:

\documentclass{article} 
\\usepackage[utf8]{inputenc}
\\usepackage{biblatex} 
\bibliography{ref}
\begin{document} 
Hällo Wörld\cite{Goe} 
\printbibliography
\end{document}

In the final result, using either method, the umlauts are inserted automatically.

Answer 3 (score 0)

I don’t know if this will apply here, but in my case, I use Zotero to produce my bib file. I had trouble exporting it with accents and I didn’t want to go through all the articles to write the accents as proposed in the answer.

I found that exporting the BibTeX file with character encoding as “Unicode (UTF-8 withou BOM)” worked, instead of “Unicode (UTF-8)”. Now I can add new articles and export them without a problem!

Question

Wikipedia lists several dot characters in Unicode. These are the ones that are ambiguous to me:

• interpunct, middle dot (·) · · U+00B7 “midpoint (in typography)”
• dot operator (⋅) ⋅ ⋅ U+22C5
• bullet operator (∙) ∙ U+2219 “(mathematics)”
• bullet (•) • • U+2022 “black small circle” “often used to mark list items”

I’m mostly interested in the Unicode characters, but Math.SE told me to try here, and LaTeX likewise has:

• \cdot
• \cdotp
• \bullet
• \textbullet

For example:

• Wikipedia shows multiplication as both “x ⋅ y” (“dot operator”) and “x ∙ y” (“bullet operator”) in the same paragraph.
• WP List of mathematical symbols uses “middle dot” for multiplication.
• WP Multiplication article uses \cdot for scalar multiplication.
• WP says the matrix dot product should be written using the “bullet operator” character, like “a ∙ b”.
• The WP Dot product article uses the LaTeX \cdot character for dot products.
• Wikipedia shows a raised decimal point example “£21·48”, which uses the “middle dot” character.
• Wikipedia notates chemistry hydrates like “CuSO4 · 5H2O”, which uses the “middle dot” character.
• Combined units can also be written with a dot, like “N·m”. Wikipedia uses a “middle dot” for this, not the “dot operator”.
• Characters in SI notations has a paragraph on combined units, seeming to say that dot operator is preferred for this, like “N⋅m”.
• Wolfram Alpha considers \cdot and · to be equivalent, as well as \bullet and •. Valid?

Of course it’s pedantic, they all look the same, and the meaning can always be assumed from context, but I’d like to know, once and for all, which Unicode/HTML and LaTeX characters are semantically correct in each application?

(If there are other examples I left out, feel free to edit the question and add them.)

Answer 2 (score 103)

The following is my personal view on this matter. I have not seen hard rules anywhere.

• Normal mathematics

The \cdot is a multiplication symbol. The following are all equivalent

It is useful in thermo-fluid dynamics formulas where there are a lot of multi character values such as Reynolds number, Prandtl number, etc.

Compound SI units (see siunitx package) is also multiplication

For vector-tensors it is element wise multiplication

• Chemical formula

I don’t know much about chemical notation (ask Joseph Wright)

• Decimal marker

The center dot as decimal marker is only found in very old books or non-scientific literature. Because it can be confused with a multiplication sign is is not used in scientific literature any more.

Answer 3 (score 33)

As the Unicode project seeks to determine the semantics of the glyphs rather than their graphical representation, this question is quite interesting.

Although I agree that all of these “bullets” could theoretically look the same (and one wouldn’t need to care about this issue at all), the semantic background can—at least to some degree—be inferred by the official Unicode charts:

Since two of the four symbols, which are subject of the discussion, are placed in Unicode Blocks named “punctuation” (see below), I would advise against using them in mathematical context. In my opinion, the annotation “= midpoint (in typography)” for the 00B7 · MIDDLE DOT symbol speaks for itself and I think one could use it in typesetting poems, for example, to mark stanzas or as a substitute for the regular space.

From my point of view, the 2022 • BULLET should be used as a list symbol exclusively.

As I think it, the 22C5 ⋅ DOT OPERATOR is the mathematical version of 00B7 · MIDDLE DOT and 2219 ∙ BULLET OPERATOR of 2022 • BULLET, respectively, when it comes to appearance. One will probably get the most “regular-looking” result with using the 22C5 ⋅ DOT OPERATOR for regular (scalar) multiplication and the 2219 ∙ BULLET OPERATOR for any other (user-defined) operation on other objects.
(See the image prepared by Danie Els.)

This can be done, from my point of view again, because the Unicode standard does not define this operator to represent any mathematical operation. Interestingly, for the 2218 ∘ RING OPERATOR symbol, the annotation does just that: “= composite function”. So I would say that semantically you are on the safe side, so to speak, as maybe the Unicode Consortium has spoken to mathematicians who told them that the dot can be—and which is being—redefined to meet the mathematician’s need. (This is very interesting when speaking about abstract algebraic structures, such as fields and vector spaces, when one uses only abstract operations.)

Since, your query for “house rules for mathematical typesetting” is not so far off, forasmuch I have experienced that in my math lectures, every professor would define these symbols at the beginning of the semester and there were differences throughout the lectures, of course.

TL;DR:
Use 22C5 ⋅ DOT OPERATOR for multiplication and 2219 ∙ BULLET OPERATOR for own operations. This is only my opinion.

Excerpts from Unicode specifications

(I think the arrows indicate references to similarly-looking rather than to semantically similar symbols.)

Block “C1 Controls and Latin-1 Supplement”, Section title “Latin-1 punctuation and symbols”

00B7 · MIDDLE DOT
= midpoint (in typography)
= Georgian comma
= Greek middle dot (ano teleia)
→ 0387 · greek ano teleia
→ 16EB ᛫ runic single punctuation
→ 2022 • bullet
→ 2024 . one dot leader
→ 2027 ‧ hyphenation point
→ 2219 ∙ bullet operator
→ 22C5 ⋅ dot operator
→ 2E31 ⸱ word separator middle dot
→ 2E33 ⸳ raised dot
→ 30FB ・ katakana middle dot

Block “General Punctuation”

2022 • BULLET
= black small circle
→ 00B7 · middle dot
→ 2024 . one dot leader
→ 2219 ∙ bullet operator
→ 25D8 ◘ inverse bullet
→ 25E6 ◦ white bullet

Block “Mathematical Operators”

2219 ∙ BULLET OPERATOR
→ 00B7 · middle dot
→ 2022 • bullet
→ 2024 . one dot leader

22C5 ⋅ DOT OPERATOR
→ 00B7 · middle dot

Question

I’ve made myself custom title-page, put it in separate .tex file and when I input it, it is numbered with 1. The very next page is numbered with 1 also, and page-number increases on the following pages. Main file looks like this

\documentclass[11pt,a4paper,draft]{article}
\\usepackage{./mystyle}

\begin{document}
\thispagestyle{empty}
\input{./titlepage.tex}
\input{./text.tex}
...
\end{document}

How do I suppress page-number on that title-page? (Why \thispagestyle{empty} doesn’t work?) edit: Here’s the title-page:

\begin{titlepage}
    \begin{center}

        % Upper part of the page
        \textsc{\large Uni}\\[0.1cm]
        \textsc{\Large Faculty}\\[2.8cm]
        \textsc{\Large Sensors}\\[0.1cm]
        {\Large Paper}\\[0.25cm] 

        % Title
        \HRule \\[0.3cm]
            { \Large \bfseries Occupancy}\\[0.3cm]
            { \huge \bfseries Tribos}\\[0.05cm]
        \HRule \\[0.05cm]

        % Author and supervisor
        \begin{center} \large
            \emph{Student:}\\
            An \textsc{Ant}
        \end{center}
        \vspace{1.8cm}
        \begin{spacing}{0}
            \tableofcontents
        \end{spacing}
        \vfill
        % Bottom of the page
        {\large \today}

    \end{center}
\end{titlepage}

Answer accepted (score 387)

You could use \pagenumbering{gobble} to switch off page numbering.

To switch it on afterwards, use \pagenumbering{arabic} for arabic numbers or alph, Alph, roman, or Roman for lowercase resp. uppercase alphabetic resp. Roman numbering.

Answer 2 (score 35)

I had the exact same problem. What worked for me was \thispagestyle{empty} after inputting the title page, not before.

Answer 3 (score 21)

Maybe try to enclose your title page (or the input file) into a \begin{titlepage} and \end{titlepage}; and put \pagenumbering{arabic} just before your main body starts.

Question

I have a table that I would like to put the Title above and a caption below. Intuitively (though I know how troublesome intuition can be in something like LaTeX), I should be able to do as below:

\begin {table}[H]
\caption {Table Title} \label{tab:title} 
\begin{center}
\begin{tabular}{ >{\centering\arraybackslash}m{1.25in}  >{\centering\arraybackslash}m{.85in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in}}
\toprule[1.5pt]
{\bf Variable Name} & {\bf Regression 1} & {\bf Mean} & {\bf Std. Dev} & {\bf Min} & {\bf Max}\\ 
\midrule
text        &  text     & text      &  text     &  text     &text\\

\bottomrule[1.25pt]
\end {tabular}
\caption {Should be a caption}
\end{center}
\end {table}

The above produces:

              Table 1: Table Title
===================================================
Name   Regression 1   Mean   Std. Dev.   Min  Max
---------------------------------------------------
text    text           text    text     text   text
===================================================
         Table 5: Should be a caption

How can I force latex to suppress the numbering/create a “caption” in the regular sense?

Answer accepted (score 45)

Use default text for the second “caption”. However,you shouldn’t use the table environment, if you do not want to float the tabular. Use a minipage instead and also tabularx in this case:

\documentclass[a4paper]{article}
\\usepackage[T1]{fontenc}
\\usepackage[utf8]{inputenc}
\\usepackage{tabularx,ragged2e,booktabs,caption}
\newcolumntype{C}[1]{>{\Centering}m{#1}}
\renewcommand\tabularxcolumn[1]{C{#1}}
\begin{document}

\begin{minipage}{\linewidth}
\centering
\captionof{table}{Table Title} \label{tab:title} 
\begin{tabular}{ C{1.25in} C{.85in} *4{C{.75in}}}\toprule[1.5pt]
\bf Variable Name & \bf Regression 1 & \bf Mean & \bf Std. Dev & \bf Min & \bf Max\\\midrule
text        &  text     & text      &  text     &  text     &text\\
\bottomrule[1.25pt]
\end {tabular}\par
\bigskip
Should be a caption
\end{minipage}

\bigskip
\begin{minipage}{\linewidth}
\centering
\captionof{table}{Table Title} \label{tab:title2} 
\begin{tabularx}{\linewidth}{@{} C{1in} C{.85in} *4X @{}}\toprule[1.5pt]
\bf Variable Name & \bf Regression 1 & \bf Mean & \bf Std. Dev & \bf Min & \bf Max\\\midrule
text        &  text     & text      &  text     &  text     &text\\
\bottomrule[1.25pt]
\end {tabularx}\par
\bigskip
Should be a caption
\end{minipage}

\end{document}

Answer 2 (score 38)

You can do this with the caption package. It provides a \caption* command that makes a caption without a number or entry into the List of Tables.

\begin{table}
\caption{Table Title}
\begin{tabular}
...
\end{tabular}
\\[10pt]
\caption*{The caption without a number}
\end{table}

Answer 3 (score 14)

You can simply add text within the table environment to make it appear as a caption, like so:

\begin {table}[H]
 \caption {Table Title} \label{tab:title} 
 \begin{center}
  \begin{tabular}{ >{\centering\arraybackslash}m{1.25in}  >{\centering\arraybackslash}m{.85in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in} >{\centering\arraybackslash}m{.75in}}
   \toprule[1.5pt]
{\bf Variable Name} & {\bf Regression 1} & {\bf Mean} & {\bf Std. Dev} & {\bf Min} & {\bf Max}\\ 
   \midrule
   text        &  text     & text      &  text     &  text     &text\\
  \bottomrule[1.25pt]
  \end {tabular}
  \\[1.5] %You can adjust how far below the table the text should appear
  Is just like a caption
 \end{center}
\end {table}

Question

What editors/IDEs are available for easing the process of writing TeX/LaTeX documents?

Please state some useful features like code completion, spell checking, building final DVI or PDF files, etc.

This question is undergoing a systematic refurbishment, see Let’s polish the Editors/IDEs question on Meta. If you’d like to see another editor feature covered here or to take care of an editor that’s not covered yet, share your ideas in that meta question.

List of editors

Links to answers.

• Archimedes
• Atom
• Auto Latex Equations for Google Docs
• Bakoma TeX Word
• Compositor
• Emacs with AUCTeX
• Emacs with WhizzyTeX
• gedit with the gedit-LaTeX-plugin
• Geany with GeanyLaTeX
• gummi
• Inlage
• IntelliJ IDEA
• jEdit
• JOVE
• Kile
• KTikZ
• Latexian
• Latexila
• LaTeX Base
• LEd
• LyX
• Notepad++
• Overleaf
• Open LaTeX Studio
• Papeeria
• QuatraTeX
• RTextDoc
• DMelt
• Scientific Word
• Scientific Workplace
• Scribes
• Scribo
• Sublime Text with LaTeXTools or LaTeXing Plugin
• ShareLaTeX
• TechWriter
• TeXlipse for Eclipse
• Texmaker
• TeXnicCenter
• TeXnicle
• TexPad
• Texpen
• TeXShop
• TeXStudio
• TextMate
• TeXworks
• Verbosus
• Vim with LaTeX-Box
• Vim with LaTeX-plugin
• Vim with Snipmate plugin and rubber
• Vim with vimtex
• Visual Studio Code with LaTeX-Workshop
• WinEdt
• Winefish
• WinShell

Answer 2 (score 335)

Emacs with AUCTeX — emacs auctex

• Platforms: Windows, Mac (incl. Aquamacs fork), Unix
• License: Free software (GPL)
• Languages: de, dk, fr, is, it, jp, nl, pl, se, sk are supported by AUCTeX language styles
• Unicode: Yes, from Emacs 23, characters are represented using Unicode
• RTL/bidirectional support: From Emacs 24, through bidi-mode
• % !TeX directives: No, but has several realizations of file local variables
• Syntax highlighting: Yes, customisable through customize and Elisp
• Code completion: Yes
• Code folding: Yes
• Spell checking: Yes
• SyncTeX: Yes
• Built-in output viewer: Yes
• Project management: org-mode, reftex-mode, speedbar

Emacs is one of the oldest programmable editors, which has basic support for TeX and friends. AUCTeX is a plugin to Emacs which provides a much more advanced support for editing LaTeX, ConTeXt, docTeX, Texinfo, and Plain TeX documents. It comes with a sophisticated auto-completion mechanism for environments and commands, supporting by default more than two hundreds LaTeX packages (but virtually any package can be automatically parsed in order to provide autocompletion for its commands and environments).

(In this screenshot, visual-line-mode is enabled. In this mode, lines that are wider than the window are broken between words. The line breaks are not added to the source file.)

RefTeX is another plugin to Emacs, independent from and complementary to AUCTeX, which aids you with the management of bibliographic sources. It makes all your references as easy to find as a C-c <key>, for both BibTeX and biblatex, and also provides convenient shortcuts for navigating between sections in your document, bound by default to C-c =:

(Note that colour themes are completely customizable)

AUCTeX supports multi-file parsing, so that huge documents with \input or \include commands are easily compiled with C-c C-c from any of their files. No more going back to the master file in order to compile.

AUCTeX’s preview-latex offers WYSIWYG previewing of formulae.

Interesting features of Emacs:

• Use table-insert along with table-generate-source and table-recognize-* functions to easily create a base for your tables.
• Lots of useful keyboard shortcuts
• Extensively documented, both in Emacs, via the Emacs and AUCTeX Texinfo manuals, and via many books in several languages.
• Supports most of vim’s features and keybindings through evil-mode.

Answer 3 (score 315)

TeXstudio — texstudio

(formerly TexMakerX)

• Platforms: Windows XP/Vista/7/8/10, OS X, Linux, FreeBSD
• License: GPL v2
• Languages: cs, de, en, es, fr, hu, ja, pl, pt_BR, ru, vi, zh_CN
• Unicode: Yes
• RTL/bidi: experimental
• % !TeX directives: Yes
• Syntax Highlighting: Yes, customizable
• Code Completion: Yes, customizable and auto-customized
• Code Folding: Yes
• Spell Checking: Yes, including grammar checking based on LanguageTool.
• SyncTeX: Yes
• Built-in Output Viewer: Yes, supports PDF
• Project Management: Yes

I’d recommend TeXstudio an interesting fork of Texmaker that I find more usable and customizable.

Here is a screen shot of TeXStudio.

Other pros:

• cross-platform,
• writing support (incr. search, folding, navigation, auto-completion, custom macros)
• inline interactive spell-checking
• support to the main latex tools, including tikz, pstricks, etc.
• multi-views: math, structure
• svn support
• runs in a usb
• pdf viewer included, but can be configured to use external viewers (also with synctex)
• live-updating inline preview for formulas and code segments
• tools for easy table editing and table-code formatting
• multiple cursors
• smart BibTeX auto-complete (including multiple, comma-separated citations) and hovering on \cite text shows a preview of the BibTeX entry
• document templates
• very active and responsive developer and community
• adjustable icon size makes it suitable for high resolution displays (preferences->show advanced options->gui scaling)

Cons:

• Does not support split editor

Question

As can be seen in above picture, there are lots of fonts or font styles that can be used in math mode.

What are all the fonts or font styles I can use in math mode, and which packages are required in order to use them?

Let’s assume I’m using standard Computer Modern or Latin Modern (lmodern) fonts.

Edit: It’d be great to see examples of what the different styles look like, probably via images.

_{I’m not interested in a reproduction of the picture, which can be found at What type of font is this?; the picture is for illustration purposes only. Furthermore, this is supposed to become a one-catches-all question for questions like the beforementioned. If I actually were looking for these fonts, I wouldn’t just lazily ask here but look e.g. at The Not So Short Introduction to LaTeX2e, tables 3.14 and 6.4 first.)}

Answer accepted (score 535)

In texdoc symbols (the Comprehensive LaTeX Symbol List) you can find Table 307:

Enlarge image

The footnotes are explained in the document. Table 327 will additionally explain bold math.

Oh and needless to say but if you were asking this question because you need more mathematical symbols, the Comprehensive List is just your document. Greek variants, Hebrew, Tables 139 to 147 are letter-like symbols … you’ll probably never run out of symbols again.

Edit: After reading this answer https://tex.stackexchange.com/a/60018/13450 I feel the need to also point to the mathalfa package that is referenced there, providing even more alternatives than shown above.

Edit 2: This answer seems so popular that I decided to include the mathalfa table as an image as well. This is taken from the mathalfa documentation and some of the fonts are commercial or need to be installed from external sources. See the documentation for more information if you consider using any of these fonts. Warning, very long table ahead (stitched together from a multi-page table).

Edit 3: With this thread being so popular for reasons I don’t entirely understand, I feel compelled to say that there is rarely a point in using more styles than regular, bold, italic, script/calligraphic (I wouldn’t even mix those) and blackboard bold. What these tables really show are typefaces you can use for these styles, not a huge number of styles (which would be pointless and ugly anyway). If, however, you are just searching for math fonts to go with your main font, the overview you probably actually want before even consulting these tables is the list of math fonts on the LaTeX Font Catalogue.

^{Click to enlarge}

Answer 2 (score 84)

LaTeX kernel

The LaTeX kernel defines several math alphabets in fontmath.ltx

\DeclareSymbolFontAlphabet{\mathrm}    {operators}
\DeclareSymbolFontAlphabet{\mathnormal}{letters}
\DeclareSymbolFontAlphabet{\mathcal}   {symbols}
\DeclareMathAlphabet      {\mathbf}{OT1}{cmr}{bx}{n}
\DeclareMathAlphabet      {\mathsf}{OT1}{cmss}{m}{n}
\DeclareMathAlphabet      {\mathit}{OT1}{cmr}{m}{it}
\DeclareMathAlphabet      {\mathtt}{OT1}{cmtt}{m}{n}

This must be completed by the previous declarations

\DeclareSymbolFont{operators}   {OT1}{cmr} {m}{n}
\DeclareSymbolFont{letters}     {OML}{cmm} {m}{it}
\DeclareSymbolFont{symbols}     {OMS}{cmsy}{m}{n}

so that we know precisely to which font correspond each math command:

1. \mathrm is the normal upright Roman font

2. \mathnormal is the normal math italic font: $\mathnormal{a}$ and $a$ give the same result

3. \mathcal is the special calligraphic font for uppercase letters only

4. \mathbf gives upright Roman boldface letters

5. \mathsf gives upright sans serif letters

6. \mathit gives text italic letters: $different\ne\mathit{different}$

7. \mathtt gives upright letters from the typewriter type font

One should notice that the argument to each of those commands is typeset in math mode, so spaces are ignored and hyphens become minus signs. Using those commands with arguments not consisting only of normal letters can give unexpected (and sometimes bizarre) results.

No package has to be loaded for being able to use those alphabets.

AMSfonts

With the amsfonts package, which is loaded automatically by amssymb one has access also to

1. \mathfrak for Fraktur (aka Gothic) letters, upper and lower case

2. \mathbb for “blackboard bold” uppercase letters

RSFS

The package mathrsfs makes available the “Ralph Smith’s Formal Script” font as a math alphabet, with the command \mathrsfs, while calrsfs will do the same but also turning \mathcal to choose the RSFS font (only uppercase letters).

Zapf’s Euler Script

The package euscript will load a different calligraphic alphabet, Euler Script, designed by Hermann Zapf. Depending on the options, it will provide \mathscr (to go along with the original \mathcal) or change \mathcal to use Zapf’s font:

\\usepackage{eucal}
\\usepackage[mathcal]{eucal}
\\usepackage[mathscr]{eucal}

The first two calls are equivalent and \mathcal will use Euler Script; the last call will provide \mathscr for Euler Script and leave \mathcal as is.

_{In my opinion only one type of calligraphic letters should be used, be it Knuth’s, RSFS or Euler Script.}

Answer 3 (score 46)

I believe your question is of a (deliberately) introductory or basic nature. Apologies if this is not your intention. A preliminary remark: Most of the text snippet you show is actually set in text mode (italics and bold-upright, resp.), and I won’t have anything to say about text-mode alphabets.

• Math italics: In many math texts since (at least?!) the middle or late 18th century (Euler’s influence?), variables and letter-like symbols are typeset by convention in a slanted or, rather, italicized style. In TeX’s math mode, letters are automatically set in math italics unless one explicitly chooses a different style. A very importance difference between math italics and ordinary italics is that the latter obey kerning and ligature rules that are of no relevance (and are, in fact, undesirable) for math. This is especially noticeable when using letters such as f which have (in italics mode) both ascenders and descenders.

  • In TeX’s Computer Modern font family, lowercase greek symbols are also set in slanted mode in math – I suppose in order to harmonize nicely with any nearby italicized latin letters.

  • When using LaTeX, \mathit{} instructs TeX to typeset the argument in text-mode italics. (In contrast, in Plain TeX the instruction \mit serves to set its argument in math italics.) In the argument of \mathit{}, spaces are ignored. To generate a snippet of text that contains spaces in math mode, use the command \textit{} instead.

• Math roman: In math mode, again by convention, abbreviations of operators such as sin, cos, tan, ln, and many others, are set in upright or “roman” style to distinguish them from ordinary symbols and letters (which are set in italics, see above). Matth roman and text roman generally look very similar but can differ when ligatures and kerning rules are involved. When in math mode, \mathrm{} instructs TeX to typeset the argument in math roman; as with \mathit, \mathrm ignores spaces. (Use \textrm to generate upright text with spaces.)

• Bold versions of mathrm and mathit: To further help the visual definition of symbols, it’s possible to embolden letters. This is often (but not always!) done for vectors. In the Computer Modern math font world, bold letters generated via \mathbf are available only in upright or “Roman” style; other math font families, though, also offer bold-italics for math.

• Math sans-serif and Math typewriter: Use of sans-serif fonts in math settings isn’t commonly done, but it can be used to set off visually certain entities that have special meanings. In your example, gen, enc, and dec are typeset with \mathsf{}, while Combine and Reveal are typeset with \mathtt.

• Special math alphabets: In addition to the preceding four math alphabets, there are also special alphabets – such as “Math Blackboard Bold” (invoked with \mathbb{}, “Math Caligraphic” (invoked with \mathcal{}), and “Math Fraktur” (invoked with mathfrak). They are frequently used for sets (e.g., \mathbb{R} and \mathbb{C} for the sets of real and complex numbers) and other entities the author wants to distinguish visually from the surrounding material. In the basic TeX distributions with the Computer Modern fonts, there are only uppercase letters for the math blackboard-bold, caligraphic, and Fraktur alphabets; however, there are packages that provide lowercase letters for these math alphabets as well.

  • In LaTeX when using the Computer Modern fonts, it’s usually necessary to load one or more specialized packages, such as amsfonts, in order to access some of the special math alphabets.

• Unlike what can be done with text-mode alphabets (to be precise, since the advent of LaTeX2e in 1994 and its “new font selection system”), math-mode alphabets can’t be combined, at least not in “basic” LaTeX when using CM fonts. E.g., the commands \mathcal{\mathbb{}} and \mathbf{\mathsf{}} won’t work as one might expect (or wish?).

OK, this is admittedly a very basic introduction to math alphabets in TeX.

Question

I’m trying to change the image size (make it look smaller than the original).

I tried with the next code but the image still shows at its original size.

\begin{figure}[h!]
\centering
\includegraphics[width=50mm]{method.eps}
\caption{Overall process}
\label{fig:method}
\end{figure}

I am using TeXnic Center with profile latex>ps>pdf

Update:

It seems to work now but I do not why

I first built the project with the profile latex => ps and then I built it with latex=>ps=>pdf

Answer accepted (score 61)

Use the scale=0.5 option in the \includegraphics command to shrink the image to 50% of its original size. That is, \includegraphics[width=50mm,scale=0.5]{method.eps}. You can use a different percentage if needed.

Answer 2 (score 12)

I usually just do \includegraphics[width=0.7\columnwidth]{figure}, where 0.7 is the fraction of the column width.

This is useful for IEEE double column papers.

Answer 3 (score 5)

This works well. scale=0.25 is to shring the image to 0.25 but can use any ratio.

Question

I can compile this table separately but when I want to compile the whole file, it gives me an error, which is fixed by removing \multirow.

\\usepackage{multirow}

\begin{table}[htbp]
\begin{center}
\begin{tabular}{|c|c|c|c|p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}|}
\hline
A & B & C & D & \multicolumn{7}{|c|}{F}  \\ \hline
\multirow{ 2}{}{1} & 0 & 6 & 230 & 35 & 40 & 55 & 25 & 40 & 35 & \\
& 1 & 5 & 195 & 25 & 50 & 35 & 40 & 45 &  &  \\ \hline
\end{tabular}
\end{center}
\label{table2}
\end{table}

Answer accepted (score 133)

There are some errors in your code; you need to give a second argument to \multirow (an explicit value for the cell width or * to use the natural width of the contents); also, \label must always appear after \caption in floating environments:

\documentclass{article}
\\usepackage{multirow}

\begin{document}

\begin{table}[htbp]
\centering
\begin{tabular}{|c|c|c|c|p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}|}
\hline
A & B & C & D & \multicolumn{7}{|c|}{F}  \\ \hline
\multirow{ 2}{*}{1} & 0 & 6 & 230 & 35 & 40 & 55 & 25 & 40 & 35 & \\
& 1 & 5 & 195 & 25 & 50 & 35 & 40 & 45 &  &  \\ \hline
\end{tabular}
\caption{A test caption}
\label{table2}
\end{table}

\end{document}

It is not clear why you are using p{...} columns if the cells are not containing paragraphs.

As a side note, I used \centering instead of the center environment to avoid adding extra vertical spacing (which in most cases is not desired).

You are not using all the columns you declared, but I guess that this was just for the example.

Question

I have seen several cases of people using the \tab command to insert a specific amount of space between objects (as opposed to the \hfill command which uses any remaining space). However, I have never been able to get \tab to work. Are there any specific packages or environments that are supposed to accompany \tab?

Answer accepted (score 51)

The command \tab exists, but it produces quite a large space. It also requires the use of the package tabto.

Alternative options are \quad and \qquad; the space produced is probably more what you are looking to create. These commands do not require extra packages and can be stacked (e.g. Stuff Over Here \quad \quad \quad More Stuff Over Here) if needed.

You might also want to try using either $\>$ or $\-$. Neither command requires any extra packages, but both must be in math mode. Although neither command by itself gives a large space like \tab does, the space produced is small. However, you can stack the commands in order to get the spacing you want.

Hope this helps.

Answer 2 (score 26)

define your own command:

\documentclass{article}
\newcommand\tab[1][1cm]{\hspace*{#1}}
\begin{document}
foo\tab bar\tab[2cm]baz

\tab foo\tab bar\tab[2cm]baz

\rule{1cm}{1pt}foo\rule{1cm}{1pt}bar\rule{2cm}{1pt}baz

\end{document}

Answer 3 (score 10)

Instead of \tab, you may use \hspace{10mm} which gives a 10mm space similar to using \tab.

Question

What is the easiest way to superscript text outside of math mode?

For example, let’s say I want to write the $n^{th}$ element, but without the math mode’s automatic italicization of the th. And what if I still want the n to be in math mode, but the th outside?

Answer accepted (score 562)

You can use \textsuperscript{th}. It sets its contents in text mode and can be used in math or text mode.

Answer 2 (score 54)

For 99% of applications, Werner’s answer is good enough. But since Marienplatz has offered a bounty, there presumably is interest in other ways to do this. So here, I show it done with a stack over a null entry. My preamble definition (output on the second line) appears to give the exact same result as \textsuperscript (output on the first line).

But then, I show how both the size of the script as well as the height of it can be simply changed with my stacking approach, shown in \footnotesize (and lowered) in the 3rd line of output, and in \tiny (and raised) in the last line.

While I stick just to the standard text font sizes, it would be trivial to instead use a \scalebox to get exactly the size of script text desired.

If there is a desire to place the script, not at a fixed elevation, but relative to the height of the character being scripted, that is easy too (just ask).

\documentclass{article}
\\usepackage{stackengine}[2013-10-15]
\newcommand\textss[1]{\stackengine{.9ex}{}{\scriptsize#1}{O}{l}{F}{F}{L}}
\begin{document}
\noindent
a\textsuperscript{th}A\textsuperscript{th}\\
a\textss{th}A\textss{th}\\
\renewcommand\textss[1]{\stackengine{.7ex}{}{\footnotesize#1}{O}{l}{F}{F}{L}}
a\textss{th}A\textss{th}\\
\renewcommand\textss[1]{\stackengine{1ex}{}{\tiny#1}{O}{l}{F}{F}{L}}
a\textss{th}A\textss{th}\\
\end{document}

Answer 3 (score 15)

In ConTeXt, you can use

\high{th}

to get the superscripts in text mode.

Question

I’m using the amsbook document class with the psamsfonts and mathpazo packages. The minus sign touches the bottom of the text line. Is there a way to slightly miniaturize and vertically center the \pm symbol with the number?

\documentclass[psamsfonts]{amsbook}
\\usepackage{mathpazo}

\begin{document}
$\pm 1$
\end{document}

Answer accepted (score 25)

For simple uses

\newcommand{\rpm}{\raisebox{.2ex}{$\scriptstyle\pm$}}

should do. If you need a very accurate measuring

\newcommand{\rpm}{\sbox0{$1$}\sbox2{$\scriptstyle\pm$}
  \raise\dimexpr(\ht0-\ht2)/2\relax\box2 }

If you need the symbol also in subscripts or superscripts, something else is needed.

The psamsfonts option is obsolete, as far as I remember.

Question

I am editing a LaTeX paper with Emacs. Sometimes I want to make a block of texts less obvious (or less important to see). Instead of totally hiding them, they should still be there. Is there an easy way to embed them in something so that it changes color (to grey for instance)?

By the way, besides changing color, are there other ways to easily make a block of texts look less important?

Answer accepted (score 246)

You can use the xcolor package. It provides \textcolor{<color>}{<text>} as well as \color{<color>} to switch the color for some give text or until the end of the group/environment. You can get different shades of gray by using black!x as a color where x is a number from 0 to 100, taken as a percentage.

\\usepackage{xcolor}
\begin{document}

This is a sample text in black.
\textcolor{blue}{This is a sample text in blue.}

\end{document}

Answer 2 (score 34)

The following seems simpler:

\documentclass{amsproc}
\\usepackage[colorlinks]{hyperref}
\begin{document}
    This is {\color{red} highlighted}, and this is not.
\end{document}

Answer 3 (score 12)

All the above answers are excellent for general purpose

If you want to highlight a syntax for a programming language we can use minted package, it provides excellent colored highlighted text.

To use this package you need to have python installed on your system (you can install python using anaconda package it’s great choice) in addition to a package called pygments (to install this package use pip install pygments) it’s a python library used to highlight programming language syntax

I’ll give a simple example of how to use it

\\usepackage{minted}
\\usemintedstyle{vim} %note here you can use different highlighting
                      %styles see the final note below

\begin{document}

\begin{minted}{python}
import matplotlib.pyplot as plt
import numpy as np

T=1
delta_T=T/200
alpha=0.5
fc=40/T
A_m=1
t=[i for i in np.arange(-5,5,1/200)]
t_arr=np.array(t)
N=len(t)

g_T=[]
for i in range(N):
    if (abs(t[i])!=(T/2*alpha)):
        g_T.append(np.sinc(t[i])*(np.cos(np.pi*alpha*t[i]/T)/
            (1- 4*alpha**2 *(t[i])**2 /(T**2))))
    else:
        g_T.append(0)
\end{minted}

\end{document}

This code will produce the following

Note you need to enable " -shell-escape " option with either LaTeX or pdfLaTeX

latex -shell-escape foo.tex

or

pdflatex -shell-escape foo.tex

If you want to get different highlights, on the command line use

pygmentize -L styles

You’ll get different styles of highlighting

CHEERS, Hizzani

Question

Lets say I have something like:

\[ Let x = number of cats \]

(This is a contrived example, but pretend we are actually inside a long align environment block…) “Let” and “number of cats” need to be written like normal text, while x= needs to be math type text.

I’ve seen this:

\[ \mbox{Let } x = \mbox{ number of cats} \]

and this:

\[ \textrm{Let } x = \textrm{ number of cats} \]

They seem to produce equivalent output, but I’m not sure which is the “correct” one. Also, they are not ideal in that the extra space needs to be placed inside the text mode block, otherwise it is ignored as math mode and butts the text right up against the math.

Ideally there would be some command which allowed embedding text into an equation, which correctly inserted leading and trailing space around the block as required without adding space inside the text block.

How does one do that “correctly”?

Answer accepted (score 188)

Another option is to use the \text{} command provided by the amsmath package.

Having said that, I doubt that it’s possible to have a single format that is “correct” for all possible requirements of leading and trailing spaces. For instance, I think you’ll find that your example looks better without the space before “number” but with the space after “Let.”

If there’s some reason that you really want to not have the space inside whatever text environment you choose, you can force a space in math mode using a single backslash followed by a space (i.e. \<space>). For example,

\[ \text{Let}\ x=\text{number of cats}. \]

Answer 2 (score 34)

I’d agree that the AMS text command is the way to go, but don’t be afraid to re-enter,

\[ 
  \text{Let $x=\text{number of cats}$} 
\]

so that the spacing is handled correctly.

Answer 3 (score 20)

I know this is an old question. But I’ve been lately thinking about this.

I don’t think that using \text is the ideal solution. I think we need to differentiate math mode from text mode. That’s all.

For me \text should only have portions of text that, because of its nature within display math can’t be typed naturally. All the rest, which is math mode, should be typed with another command. In this “rest” we have at least two kinds of text, for example: \{ x,\ \firstkind{such that $x$ is son of Julia} \} and x = \secondkind{number of cats}. For me, none of this two ones should be written with the outer text mode that \text provides.

\[ 
  \text{Let } x = \var{number of cats}
  \text{, and also }
  \var{Overlap Area} = \frac{\Area(\var{Detection} \cap \var{Ground Truth})}
                            {\Area(\var{Detection} \cup \var{Ground Truth})}
\]

If we think in terms of {center} and $, I think it’s clear that

\begin{center}
  Let $x = \var{number of cats}$, and also
  $\var{Overlap Area} = \frac{\Area(\var{Detection} \cap \var{Ground Truth})}
                             {\Area(\var{Detection} \cup \var{Ground Truth})}$
\end{center}

Now the question is how to define \var or whatever name we choose for that thing that is kind of text, but is really math mode and not just text linking math parts, may be one wants \textmath, \mtext, \mthtxt, etc. I used \var for clarity, but may be that command is used so one needs to define another name.

I think it should be typed in the math font \mathrm (ideally) or in the closest to it (which means no \text that changes depending on the outer text font) like \textnormal if the text font is from the family of the math font. The problem with \mathrm is the spacing, but that could be sorted out.

The other case \{ x,\ \mathtext{such that $x$ is son of Julia} \} should also not depend of the outer font, so we should define \mathtext probably with \textnormal or something like that.

I hope this different forms get differentiated in LaTeX3, which would bring more “robustness” and less ambiguities to the process of writing documents with math involved.

Last, imagine a beamer presentation with sans serif font for text, and the usual Computer Modern for math mode; and think about which parts should be in sans serif and which not:

\[
  \text{Let } x = \text{number of cats} \text{, and also } \{ x,\ \text{such that $x$ is son of Julia} \}
\]

I do think it’s clear that only two of those four \text should be in sans serif.

Question

I am using the following code to put my two figures side by side with different captions,

\begin{figure*}[t!]
    \centering
    \begin{subfigure}[b]{0.5\textwidth}
        \centering
        \includegraphics[height=1.2in]{a}
        \caption{Lorem ipsum}
    \end{subfigure}%
    ~ 
    \begin{subfigure}[b]{0.5\textwidth}
        \centering
        \includegraphics[height=1.2in]{b}
        \caption{Lorem ipsum, lorem ipsum,Lorem ipsum, lorem ipsum,Lorem ipsum}
    \end{subfigure}
    \caption{Caption place holder}
\end{figure*}

I get the following output:

However, I want to position both my images vertically same line, like the following:

Desired output:

Answer accepted (score 115)

Use the t option for the alignment of the subfigures:

\begin{figure*}[t!]
    \centering
    \begin{subfigure}[t]{0.5\textwidth}
        \centering
        \includegraphics[height=1.2in]{a}
        \caption{Lorem ipsum}
    \end{subfigure}%
    ~ 
    \begin{subfigure}[t]{0.5\textwidth}
        \centering
        \includegraphics[height=1.2in]{b}
        \caption{Lorem ipsum, lorem ipsum,Lorem ipsum, lorem ipsum,Lorem ipsum}
    \end{subfigure}
    \caption{Caption place holder}
\end{figure*}

Using this, both images will be aligned on top:

Question

When typing < or > in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I’m not in math mode.

Answer accepted (score 215)

Geoffs tip with \textless and \textgreater will work well for you. However, you could type these symbols < and > directly in your editor and they would be correctly printed if you use the recommended font encoding, Cork resp. T1:

\\usepackage[T1]{fontenc}

Have a look at the T1 encoding table, search for the symbols < and >. Afterwards, open the OT1 encoding table, which is the default. At the two corresponding places you will find the upside down exclamation resp. quotation mark. That should explain it.

For further reasons, why you should use T1 encoding, have a look at this question: Why should I use \usepackage[T1]{fontenc}?

You should use a font supporting T1. For instance use the very good Latin Modern font, derived from the standard fonts:

\\usepackage{lmodern}

Or install the cm-super package which provides the standard Computer Modern fonts with T1 support.

Answer 2 (score 97)

Use \textless and \textgreater.

Answer 3 (score 18)

What I usually do is just enter mathmode to type them, e.g. This object is $<$ that object.

Question

I tried using the below code but it works only for 2⨉2 matrix.

 \[
   M=
  \left[ {\begin{array}{cc}
   1 & 2 \\
   3 & 4 \\
  \end{array} } \right]
\]

Now the following doesn’t work for me:

\[
  M=
  \left[ {\begin{array}{cc}
   1 & 2 & 3 & 4 & 5\\
   3 & 4 & 5 & 6 & 7\\
  \end{array} } \right]
\]

Answer accepted (score 41)

In the example you have, you need the opening line to be

\left[ {\begin{array}{ccccc}

rather than

\left[ {\begin{array}{cc}

When you start with just two cs, you’re telling it the matrix only has two columns (and that you want them centered). Then it breaks when you give it data for 5 columns.

Answer 2 (score 80)

A better way to do it, as the TheHe meantioned, is with the amsmath package:

\documentclass{article}
\\usepackage{amsmath}
\begin{document}

\[
M=
  \begin{bmatrix}
    1 & 2 & 3 & 4 & 5 \\
    3 & 4 & 5 & 6 & 7
  \end{bmatrix}
\]

\end{document}

The bmatrix environment will give you [] braces. () braces are also very common. They are created with the pmatrix environment. To include a matrix inline, you can write:

$M = \left\[ \begin{smallmatrix} 1 & 2 \\ 3 & 4 \end{smallmatrix} \right\]$

Answer 3 (score 12)

if you use the amsmath package, you can chose out of a lot of matrices like pmatrix or bmatrix.

Check out this list at Wikibooks.

Question

How can I get the ‘real number’ sign (something like \mathbb{R} with the amssymb package in LaTeX) in XeTeX?

Answer accepted (score 8)

Auto-answer:

\input amssym.tex
${\Bbb R}$
\bye

works fine

Answer 2 (score 131)

How about this?

\documentclass{article}
\\usepackage{amssymb}
\begin{document}
\begin{tabular}{ll}
Plain-\TeX{}:   & ${\rm I\!R}$\\
amssymb:        & $\mathbb{R}$
\end{tabular}
\end{document}

Answer 3 (score 11)

You should put your symbol format definitions in another TeX file; publications tend to have their own styles, and some may use bold Roman for fields like R instead of blackboard bold. You can swap nams.tex with aom.tex. I know, this is more common with LaTeX, but the principle still applies.

For example:

% paper.tex
\input nams.tex
$\realnumbers$ is connected.

% nams.tex
\def\realnumbers{\mathbb{R}}
% more definitions for the Notices.

% aom.tex
\def\realnumbers{\mathbf{R}}
% more definitions for the Annals.

Just change one line in paper.tex to submit to the Annals instead of the Notices.

Question

How to type these special letters from European languages in latex? ä, é, and L’?

Answer 2 (score 146)

You can type texdoc lshort in a command line (Command Prompt on Windows, Terminal on Linux/Mac OS X). Then have a look at Table 2.2 in Section 2.4.8. I’ll quote it for you here.

Answer 3 (score 127)

With pdfLaTeX

Save your file as UTF-8 and put

\\usepackage[utf8]{inputenc} % usually not needed (loaded by default)
\\usepackage[T1]{fontenc}

in your preamble. With current (>2018) distributions inputenc is no longer needed if the file is UTF-8, as that is the assumed default encoding.

Then you can just type the characters normally into your source file.

With XeLaTeX or LuaLaTeX

ALternatively you can use XeLaTeX or LuaLaTeX which accept UTF-8 input natively. In that case you need to add only:

\\usepackage{fontspec}

to your preamble. You should not load inputenc (or fontenc) in this case. These engines allow you to use any font installed on your system. See the fontspec documentation for more details.

Lousy editor

If your text editor doesn’t support UTF-8 encoded files, you should probably get another editor. But if you’re stuck with one, you can also use:

\\usepackage[latin1]{inputenc} % for PCs
\\usepackage[applemac]{inputenc} % for Macs

and save the files in the default encoding for your machine. You cannot use XeLaTeX or LuaLaTeX with such files, however.

Question

How do you guys go about controlling column padding in tables?

Update

To clarify, I’m looking for a way to control both vertical and horizontal padding. So, if I had a simple table like in the following code snippet, I could pad the columns and make them look a bit less… ugly. :P

\begin{tabular}{|l|l|}
    \hline
    column 1 & column 2 \\ 
    \hline
    I really would like this less & crammed\\
    \hline
\end{tabular}

I tried this by using the command \vspace but it leaves gaps in the vertical lines.

Answer accepted (score 231)

Use a default tabular environment without package booktabs and add right before and after the environment:

\bgroup
\def\arraystretch{1.5}%  1 is the default, change whatever you need
\begin{tabular}{|c|...}
...
\end{tabular}
\egroup

and also use column type c instead of l, If you want more horizontal space between the columns then use \setlength\tabcolsep{<whatever length>}.

Answer 2 (score 271)

_{The following suggestions are applicable to tabular- and array-like structures and for the most past applies to both text and math mode, including *matrix environments.}

Vertical padding

Vertical padding is possible in a global way using @Herbert’s answer. That is, to redefine the array stretch factor <factor> using

\renewcommand{\arraystretch}{<factor>}

However, as the name suggests, this is a factor and not a length. So, it would be difficult to provide an adequate factor that would add (say) 15pt above/below each row. There are other options available for this.

Vertical padding is also possible in a manual way or on a per-row basis using the optional parameter to end a tabular line; \\[<len>] where <len> is any familiar TeX length. A final alternative is to use the set the length \extrarowheight provided by the array package.

Here’s an example showing the above three possibilities:

\documentclass{article}
\\usepackage[landscape]{geometry}% http://ctan.org/pkg/geometry
\\usepackage{array}% http://ctan.org/pkg/array
\begin{document}

% =========== FACTOR approach ===========
{\renewcommand{\arraystretch}{2}%
\begin{tabular}{|l|l|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular}} \quad
% =========== LENGTH approaches ===========
\begin{tabular}{|l|l|}
  \hline
  column 1 & column 2 \\[4ex]
  \hline
  I really would like this less & crammed \\[5pt]
  \hline
\end{tabular} \quad
{\setlength{\extrarowheight}{20pt}%
\begin{tabular}{|l|l|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular}}
\end{document}

Note how the “factor” approach is more evenly distributed than the “length” approaches. This is to be expected. However, these techniques can also be combined, if needed. Also, the use of \\[<len>] provides “bottom padding”, while setting \extrarowheight adds “top padding”. Finally, note the grouping within the example: \renewcommand and \setlength are made local by putting is inside {...}. That is, the value/length of \arraystretch/\extrarowheight revert back to the original value before resetting it at the end of the group.

Horizontal padding

Similar approach to horizontal padding of columns exist. The use of tabularx or tabulary might be considered factor-based, as well as using \extracolsep{\fill}. However, these all pertain to fixed-width tables, with the first being addressed in @cmhughes’ answer. Here is a description of tabulary usage, taken from the UK TeX FAQ entry on Fixed-width tables:

The tabulary package … provides a way of “balancing” the space taken by the columns of a table. The package defines column specifications C, L, R and J, giving, respectively, centred, left, right and fully-justified versions of space-sharing columns. The package examines how long each column would be “naturally” (i.e., on a piece of paper of unlimited width), and allocates space to each column accordingly.

A length-based approach could include a per-column addition of a separate length using the @{...} “column specifier”. Also, modifying the length \tabcolsep (or \arraycolsep if you’re working with an array) would do this for all columns, and is therefore more generic. Finally, the array package also provides a means for insert stuff before a column entry and after it using >{<before>} and <{<after>}. Here are some examples:

\documentclass{article}
\\usepackage[landscape]{geometry}% http://ctan.org/pkg/geometry
\\usepackage{array}% http://ctan.org/pkg/array
\begin{document}
% =========== FACTOR approach ===========
\begin{tabular*}{500pt}{@{\extracolsep{\fill}}|l|l|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular*}

\bigskip

% =========== LENGTH approaches ===========
\begin{tabular}{|@{\hspace{2em}}l@{}|l@{\qquad}|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular} \quad
{\setlength{\tabcolsep}{2em}
\begin{tabular}{|l|l|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular}}

\medskip

\begin{tabular}{|>{\hspace{1pc}}l|l<{\hspace{-2pt}}|}
  \hline
  column 1 & column 2 \\
  \hline
  I really would like this less & crammed \\
  \hline
\end{tabular}
\end{document}

Of course, if all columns should have the same specifier, using the “multiple column specifier” *{<num>}{<col spec>} is a better choice.

In the above examples, geometry was loaded to adjust for a possibly wide display.

Alternative padding approaches

Another way of regulating vertical padding would be to insert so-called (vertical) struts in the form of a zero-width rule (say). For example, using \rule{0pt}{2em}stuff inserts a 2em strut before stuff, thereby increasing the vertical height of the cell containing stuff. Similarly, padding below a cell could be achieved using \rule[-1em]{0pt}{1em}stuff which drops the strut 1em below the baseline.

The same goes for horizontal padding via zero-height struts.

Answer 3 (score 66)

This is an old question, but I’ve run into the same problem, and all these solutions seemed too complex for my needs, namely in respect to horizontal padding. Looking for a rapid solution similar to the one proposed above for vertical padding (\arraystretch), I’ve found \setlength{tabcolsep} to be a good candidate.

Applying it on the example, it would be:

\setlength{\tabcolsep}{0.5em} % for the horizontal padding
{\renewcommand{\arraystretch}{1.2}% for the vertical padding
\begin{tabular}{|l|l|}
    \hline
    column 1 & column 2 \\ 
    \hline
    I really would like this less & crammed\\
    \hline
\end{tabular}
}

and the following is the difference:

Question

I know how to define a package or a class, but how do I make it available (to myself) at all times?

Say I have the package file commonstuff.sty (or myprettyclass.cls), that I want to be able to include in any .tex file I create on my computer. Where do I put it? Do I need to run some installer on it, or is it enough to keep it in a certain folder?

Note: I know I can just place it in the same folder as the .tex file, but that’s not what I’m after here. I’m looking for a way to “install” the package centrally on my computer.

Answer accepted (score 329)

You could create a folder below your TeX home directory and put your .sty file therein. Use this command at the command prompt to find out where:

kpsewhich -var-value=TEXMFHOME

On my computer it shows

C:/Users/stefan/texmf

but it might also be ~/texmf/ on a Linux or Unix computer.

Following the TeX directory structure, you should place your file in a subdirectory like ~/texmf/tex/latex/commonstuff/, according to Arthur’s comment below. This has the advantage that it is not necessary to update the package database as TeX searches your personal texmf tree directly. If there is an ls-R file in your home texmf tree you can safely delete it as TeX will not use it anyway. (Note: this assumes your personal tree is on a local file system: users with remotely-mounted home folders may still need to hash.)

Regarding MiKTeX, have a look at the section “Installing sty or cls files” in the answer to the question How can I manually install a package on MikTex (Windows).

You can then verify what file will be used with:

kpsewhich filename.sty

This will show the path to the file picked up by the TeX implementation.

Answer 2 (score 190)

All of the other answers cover things quite well, but I thought a slightly different version might be helpful.

There are two parts to telling TeX about a new .sty file. First, you have to put it in the ‘right’ place and second you need to update the database TeX uses to find files. The place to put the file depends on your operating system. Assuming you have a standard installation, this will probably be:

• Windows 10 (and miktex)
  C:\Users\<user name>\Appdata\Local\MikTex\<number>\tex\latex\local\
• Windows Vista/7 C:\Users\<user name>\texmf\tex\latex\local\
• Windows XP C:\Documents and Settings\<user name>\texmf\tex\latex\local\
• Linux ~/texmf/tex/latex/local/
• Mac OS X /Users/<user name>/Library/texmf/tex/latex/local/

Note: the local/ folder might not exist; in this case, go ahead and create it.

A few of notes on that. First, on Windows the ‘Users’ part of the location is language dependent. Second, I’ve represented your home/user folder as ‘<user name>’: this will obviously be dependent on your system. The folder I’ve indicated may well not exist: you may just have the texmf part, bits within that or nothing at all. The file location is important, and although you could just put your file inside texmf/tex/latex is is usual to keep things organised by package. The local folder is reserved for stuff installed on individual machines.

Letting TeX ‘know’ about the file means running a program that builds a database of file locations. There are graphical interfaces to do this, but the way that works on all operating systems is to use the Command Prompt/Terminal and type texhash. This will build the databases for your tree (the one that is in your home folder). Once the ‘hash’ is created TeX should be able to find your file. For recent TeXLive distributions, this step is not necessary for files in the local folder.

Answer 3 (score 61)

As already mentioned by Arthur, .sty or .cls files must be in some subdirectory of tex\latex which can be in any directory of any drive.

See the following screenshot, it shows how the path to my packages and classes is.

I will explain two cases, registering to MikTeX and registering to TeX Live.

Registering to MikTeX

Open Settings (Admin), select Roots tab, and add my path E:\A\My LaTeX\MyLibrary.

Note that the trailing \tex\latex\misc must not be included !

Afterwards, select General tab and press Refresh FNDB button.

Registering to TeX Live

See How to register my own packages or classes in a separate drive to TeX Live installation?

Question

Possible Duplicate:
Vertical space in lists

How to change the space between the itemize “items” in LaTeX so that I can continue to use the “itemize” and “item” tag without needing to redefine any new tags?

Answer 2 (score 302)

\itemsep is the length you’ll want to change.

As an example:

\begin{itemize}
  \setlength\itemsep{1em}
  \item one
  \item two
  \item three
\end{itemize}

Question

I would like to create a table with some columns’ width specified, while the text in those columns should be centered both horizontally and vertically. I found out that

\\usepackage{array}
\begin{tabular}{| c | c | m{5cm} |}

vertically centers the text in the last column, but justifies it horizontally (like text in normal paragraphs).

Update: With Jake’s method, it seems both \\ and \hline cause an error. How to fix it?

Answer accepted (score 370)

A comprehensive solution (based on this answer) is to define new column types (say, L, C, and R) that take their width as argument and do the following:

• Issue \raggedright, \centering, or \raggedleft to achieve the desired horizontal alignment,

• Declare \let\newline\\ to allow to use \newline for manual line breaks within a cell (note that \centering & friends change the meaning of \\ – this is the problem with Jake’s solution),

• Issue \arraybackslash (i.e., \let\\\tabularnewline) to allow (again) to use \\ for ending rows,

• Issue \hspace{0pt} to allow the first word in a cell to be hyphenated.

In the example below, the new column types are based on (vertically centered) m-columns, but one may use (top- or bottom-aligned) p- or b-columns as well.

\documentclass{article}

\\usepackage{array}
\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{R}[1]{>{\raggedleft\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}

\begin{document}

\begin{tabular}{| c | L{3cm} | C{3cm} | R{3cm} |}
foo &
A cell with text that wraps around, is raggedright and allows \newline
    manual line breaks &
A cell with text that wraps around, is centered and allows \newline
    manual line breaks &
A cell with text that wraps around, is raggedleft and allows \newline
    manual line breaks \\
\end{tabular}

\end{document}

Answer 2 (score 65)

The ‘m’ column type only centers the text vertically; to get it also centered horizontally, you can use the >{cmd} syntax, which adds a command before each cell in the specified column:

\documentclass{article}
\\usepackage{array}
\begin{document}
\begin{tabular}{| c | c | >{\centering}m{5cm} |}
Abc & Bcd & A long cell with text that wraps around and is centered
\end{tabular}
\end{document}

As Stefan Kottwitz pointed out in his comment, this can also be be wrapped in a new column type that you can define using

\newcolumntype{C}[1]{>{\centering}m{#1}}

Then you can define the above table using

begin{tabular}{| c | c | C{5cm} |}

Answer 3 (score 5)

I found a very different technique that also works:

With the package ragged2e you can issue the command \RaggedRight outside the tabular environment and get ragged right inside p- or m-columns of a tabular environment.

Here is an example document:

\documentclass{article}
\\usepackage{array}
\\usepackage{ragged2e}
\begin{document}
{\RaggedRight
    \begin{tabular}{| c | m{3cm}}
    foo &
A cell with text that wraps around, is raggedright and allows \newline
manual line breaks \\ 
\end{tabular}
}% end of \RaggedRight
\end{document}

Question

I would like to typeset a draft of my document with double linespacing so that my collaborators have space to write in their edits (with a pen). How do I do it?

Answer accepted (score 139)

The setspace package does it for you, but it turns doublespacing off within footnotes and floats like figure and table captions. That’s usually desired.

But if you don’t want to use setspace, perhaps because of the mentioned reason, you could use the command \linespread, for instance:

\linespread{1.5}

A package may be preferred over such a command though.

Answer 2 (score 179)

Simple: put

\\usepackage{setspace}
\doublespacing
% or:
%\onehalfspacing

into your preamble. (TeX-FAQ advises for setspace and against doublespace.)

Answer 3 (score 18)

The simplest possible way is probably by using the plain TeX macro \openup

E.g. if you want double line spacing, add a single line-height to the line spacing (1em) using:

\openup 1em

(don’t use any braces around the argument, the macro takes its argument as if you had written =1em, i.e. an assignment of a dimension).j

Following that macro’s invocation all lines will have a single line’s height extra to separate them, later on you can revert this effect by giving the negative argument:

\openup -1em

This macro works by increasing (\advance) the three parameters (\lineskip, \baselineskip and \lineskiplimit) that govern line spacing by the given amount. It’s defined in plain.tex if you want to have a look at it.

Question

I want to represent, say, the closure of a set or the extended reals, e.g., $\bar{\mathbb{R}}$ but unfortunately this creates a bar that is much too small (horizontally) and can barely be seen. On the other hand, $\overline{\mathbb{R}}$ creates a line that is too long. I need something that’s just right, in between the bar and the overline. What would be my best choice?

Answer accepted (score 74)

Here is a command \xoverline[width percent]{symb} that will do it. Note that it will not scale inside sub or superscripts. If you need that, everthing has to go through a \mathchoice resulting in a lot more complex code.

\documentclass{article}
\\usepackage{amsmath,amssymb}
\makeatletter
\newsavebox\myboxA
\newsavebox\myboxB
\newlength\mylenA

\newcommand*\xoverline[2][0.75]{%
    \sbox{\myboxA}{$\m@th#2$}%
    \setbox\myboxB\null% Phantom box
    \ht\myboxB=\ht\myboxA%
    \dp\myboxB=\dp\myboxA%
    \wd\myboxB=#1\wd\myboxA% Scale phantom
    \sbox\myboxB{$\m@th\overline{\copy\myboxB}$}%  Overlined phantom
    \setlength\mylenA{\the\wd\myboxA}%   calc width diff
    \addtolength\mylenA{-\the\wd\myboxB}%
    \ifdim\wd\myboxB<\wd\myboxA%
       \rlap{\hskip 0.5\mylenA\\usebox\myboxB}{\\usebox\myboxA}%
    \else
        \hskip -0.5\mylenA\rlap{\\usebox\myboxA}{\hskip 0.5\mylenA\\usebox\myboxB}%
    \fi}
\makeatother
\begin{document}

$|\xoverline{W}|~~
 |\xoverline{i}|~~
 |\xoverline[3.0]{i}|$

\bigskip

$\bar{\mathbb{R}}~~\overline{\mathbb{R}}~~\xoverline{\mathbb{R}}$

\end{document}