# Vertical spacing between fractions in matrix environment [duplicate]

When a fraction is used in a matrix environment, not enough vertical space is put between the rows. Wikibooks recommends using the \em command, but this seems like an inelegant solution. Is there an elegant solution?

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## marked as duplicate by Werner, Caramdir, Gonzalo Medina, egreg, Stefan Kottwitz♦Nov 10 '11 at 15:45

It is always best to compose a MWE that illustrates the problem including the \documentclass so that those trying to help don't have to recreate it. –  Peter Grill Nov 2 '11 at 23:30
@PeterGrill I would have, but this seems like such an obvious scenario that an MWE isn't necessary and actually clutters the question. Am I wrong? –  Quinn Culver Nov 2 '11 at 23:37
–  Werner Nov 2 '11 at 23:39
@Quinn: MWEs are always welcome and definitely encouraged, since subjective views may interpret questions differently. –  Werner Nov 2 '11 at 23:41
Yeah I realize it is not that hard, but anyone who wants to provide a solution will have to create it to test it and if you provide one to start there is less chance of misinterpretations. –  Peter Grill Nov 3 '11 at 0:09

If you use an array environment then you can use the command

\renewcommand{\arraystretch}{2.5}


and tweak it to whatever you would like. I have loaded the amsmath package to use \dfrac

\documentclass{article}
\usepackage{amsmath}

\begin{document}

Default:
$\left[ \begin{array}{ccc} \dfrac{5}{6} & \dfrac{1}{6} & 0 \\ \dfrac{5}{6} & 0 & \dfrac{1}{6} \\ 0 & \dfrac{5}{6} & \dfrac{1}{6} \end{array} \right]$
\renewcommand{\arraystretch}{2.5}
Stretched:
$\left[ \begin{array}{ccc} \dfrac{5}{6} & \dfrac{1}{6} & 0 \\ \dfrac{5}{6} & 0 & \dfrac{1}{6} \\ 0 & \dfrac{5}{6} & \dfrac{1}{6} \end{array} \right]$
\end{document}

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But isn't this bad because it used array where matrix is more appropriate? –  Quinn Culver Nov 4 '11 at 15:37
@Quinn: that's up to you! If you'd prefer to use matrix then have a look at the links that people have posted as comments –  cmhughes Nov 4 '11 at 15:46

One approach is to add extra space between specific lines, with an optional argument to \\:

\left[\begin{matrix}
\frac{1}{2} & \frac{3}{2} \\
\frac{5}{2} & \frac{7}{2}
\end{matrix}\right]


produces

While

\left[\begin{matrix}
\frac{1}{2} & \frac{3}{2} \$6pt] \frac{5}{2} & \frac{7}{2} \end{matrix}\right]  produces - Note that the OP wanted to avoid this approach – cmhughes Nov 3 '11 at 2:12 @cmhughes: Hm, I didn't see that in the post. Where was it stated? – jtbandes Nov 3 '11 at 4:26 Wikibooks recommends using the \em command, but this seems like an inelegant solution. No big deal though, it gets the job done :) – cmhughes Nov 3 '11 at 4:48 OK, I did see that, so I guess my question is... is \em equivalent to \\? – jtbandes Nov 3 '11 at 4:54 The Wikibooks link recommends using \\[0.3em] and you used \\[6pt]. The similarity (in my mind) is that both are manual approaches. – cmhughes Nov 3 '11 at 5:14 In plain-tex format at least, \matrix calls \normalbaselines, which resets the (base)lineskip(limit)'s to normal(base)lineskip(limit)'s. Plain also has a macro called \openup<dimen> which increases the (base)lineskip(limit)'s by given <dimen>. So it would seem logical to define a macro \openupnormal, which would do the same as \openup, only for normal(base)lineskip(limit)'s: \catcode@=11 \def\openupnormal{\afterassignment\@penupnormal\dimen@=} \def\@penupnormal{\advance\normallineskip\dimen@ \advance\normalbaselineskip\dimen@ \advance\normallineskiplimit\dimen@} \catcode@=12  so that one could do:  \left[ \openupnormal1\jot\matrix{ % inside this group, increase the % normal(base)lineskip(limit)'s by 1 jot {5\over6} & {1\over6} & 0 \cr {5\over6} & 0 & {1\over6} \cr 0 & {5\over6} & {1\over6} \cr } % the group ends here, and so does the effect of \openupnormal \right] \quad \left[ \matrix{ {5\over6} & {1\over6} & 0 \cr {5\over6} & 0 & {1\over6} \cr 0 & {5\over6} & {1\over6} \cr } \right]  \bye  (Note that there is no \displaystyle in effect in the above fractions, unlike in \dfrac) - I use LaTeX, not plain-TeX. Will this still work? Is there an analogous solution for LaTeX? – Quinn Culver Nov 4 '11 at 15:36 I tried it with LaTeX and no errors. But I suppose you'd write things differently with LaTeX (\makeatletter/\makeatother instead of \catcode's, \frac/\dfrac instead of {x\over y}, \\[/\$ instead of  etc. –  morbusg Nov 4 '11 at 15:48