I want to type a system of equations delimited by the left curly brace. And I tried using the \left{ with aligned, and cases, and array, and numcases. But there are some difference between the results of these four methods. Here is the screen-shots and the source file:
\documentclass{article}
\usepackage{amsmath,amssymb,cases}
\begin{document}
\begin{align*}
&\left\{\begin{aligned}
&x=x,\\
&u=u(x,t).
\end{aligned}\right.
~~~&& \begin{cases}
x=x,\\
u=u(x,t).
\end{cases}
~~ &&
\left\{\begin{array}{l}
x=x,\\
u=u(x,t).
\end{array}\right.\\
&\text{align} && \text{cases} &&\text{array}
\end{align*}
using numcases:
\begin{numcases}{}
x=x,\nonumber\\
u=u(x,t). \nonumber
\end{numcases}
\end{document}
My question is how can I adjust the space between the top tip of left curly brace and the first line of the equations, so that the results of using array etc is the same as that of using numcases. At present, I have no way of doing this.
When I tried using scalerel.sty, the result is as above: I do not know why? May be I was wrong in installing the scalerel.sty.
[1] : http//...
at the very end of the post. That's why documentclass was sticking out ;) – percusse May 20 '13 at 12:14\begin{array}{l}
with\begin{array}{@{}l}
, you'll get rid of some horizontal space. By default, arrays include a bit of horizontal padding around each column, and@{}
removes this. – John Wickerson May 20 '13 at 13:04