Formatting of an array of equations (left alignment)

Question

I have the following text in a matrix environment. Is there a better way to format it, say with each column being left ordered, and how can this be done?

$$
\begin{matrix}
\Gamma^{i}_{\mbox{ }0i}=\frac{\dot{a}}{a} \mbox{ ,i from 1..3 }
  & \Gamma^{0}_{\mbox{ }11}=\frac{a\dot{a}}{1-kr^{2}}
  & \Gamma^{0}_{\mbox{ }22}=\dot{a}ar^{2}
  & \Gamma^{0}_{\mbox{ }33}=\dot{a}ar^{2}\sin^{2}{(\theta)}
\\
\Gamma^{1}_{\mbox{ }11}=+\frac{kr}{1-kr^{2}}
  & \Gamma^{1}_{\mbox{ }22}=-r(1-kr^{2})
  & \Gamma^{1}_{\mbox{ }33}=-(1-kr^{2})r\sin^{2}{(\theta)}
  & \Gamma^{2}_{\mbox{ }12}=\frac{1}{r}
\\
\Gamma^{3}_{\mbox{ }23}=\cot{(\theta)}
  & \Gamma^{3}_{\mbox{ }13}=\frac{1}{r}
  & \Gamma^{2}_{\mbox{ }33}=-\sin{(\theta)}\cos{(\theta)}
\end{matrix}
$$

enter image description here

Welcome to TeX.sx! Please add a minimal working example (MWE) that illustrates your problem. It will be much easier for us to reproduce your situation and find out what the issue is when we see compilable code, starting with \documentclass{...} and ending with \end{document}. — jub0bs, Mar 23 '13 at 16:52
For future reference, see Why is \[ …\] preferable to $$? — Werner, Mar 23 '13 at 17:00

score 3 · Answer 1 · edited Jun 09 '17 at 19:12

3

I'd change the way you lay out the formulas, reserving a row for the "0i" case, one for \Gamma^1, one for \Gamma^2 and one for \Gamma^3.

The first row is artificially made shorter to TeX's eyes, so that the textual annotation is not taken into consideration for the spacing.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\begin{aligned}
&  \Gamma^{i}{}_{0i}=\frac{\dot{a}}{a}
  \makebox[0pt][l]{\quad($i$ from $1$ to $3$)}
\\
&  \Gamma^{0}{}_{11}=\frac{a\dot{a}}{1-kr^{2}}
&& \Gamma^{0}{}_{22}=\dot{a}ar^{2}
&& \Gamma^{0}{}_{33}=\dot{a}ar^{2}\sin^{2}(\theta)
\\
&  \Gamma^{1}{}_{11}=+\frac{kr}{1-kr^{2}}
&& \Gamma^{1}{}_{22}=-r(1-kr^{2})
&& \Gamma^{1}{}_{33}=-(1-kr^{2})r\sin^{2}(\theta)
\\
&  \Gamma^{2}{}_{12}=\frac{1}{r}
&& \Gamma^{2}{}_{33}=-\sin(\theta)\cos(\theta)
\\
&  \Gamma^{3}{}_{23}=\cot(\theta)
&& \Gamma^{3}{}_{13}=\frac{1}{r}
\end{aligned}
\]
\end{document}

Note that staggering of indices can be obtained more easily with {}_ than with \mbox{ } in the subscript.

enter image description here

Check Why is \[ … \] preferable to $$? for why $$ should never be used.

edited Jun 09 '17 at 19:12

David Carlisle

757,742

answered Mar 23 '13 at 17:14

egreg

1,121,712

1

how did that \Gamma^{2}{}_{33} sneak down into the last line? – barbara beeton Mar 23 '13 at 17:17
@barbarabeeton Because I didn't see well the superscript. :) – egreg Mar 23 '13 at 17:23
looks much nicer now. still one niggle -- wouldn't the 13 entry logically make more sense before the 23 one in the last line? – barbara beeton Mar 23 '13 at 17:49
@barbarabeeton Maybe. I consider this just an example (and it was so in the original post). – egreg Mar 23 '13 at 17:51

David Carlisle · Answer 2 · 2017-05-27T19:16:37.607

enter image description here

Please always post complete documents not just fragments. Here I've use align* and also removed the \mbox{ } markup. It's too wide at the standard size, but I don't know what page sizes you are using. It can always be re-arranged to have 3 rather than 4 equations on each line.

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{align*}
{\Gamma^{i}}_{0i}&=\frac{\dot{a}}{a} \mbox{ ,i from 1..3 }
  & {\Gamma^{0}}_{11}&=\frac{a\dot{a}}{1-kr^{2}}
  & {\Gamma^{0}}_{22}&=\dot{a}ar^{2}
  & {\Gamma^{0}}_{33}&=\dot{a}ar^{2}\sin^{2}{(\theta)}
\\
{\Gamma^{1}}_{11}&=+\frac{kr}{1-kr^{2}}
  & {\Gamma^{1}}_{22}&=-r(1-kr^{2})
  & {\Gamma^{1}}_{33}&=-(1-kr^{2})r\sin^{2}{(\theta)}
  & {\Gamma^{2}}_{12}&=\frac{1}{r}
\\
{\Gamma^{3}}_{23}&=\cot{(\theta)}
  & {\Gamma^{3}}_{13}&=\frac{1}{r}
  & {\Gamma^{2}}_{33}&=-\sin{(\theta)}\cos{(\theta)}
\end{align*}

\end{document}

Formatting of an array of equations (left alignment)

2 Answers2