I would like to put a matrix in a figure caption. The following example demonstrates the idea:
\documentclass{amsart}
\usepackage{graphics, epsfig, psfrag}
\begin{document}
\begin{figure}
\begin{picture}(0,0)(-72,-75)
\put(12,-68){\small$\alpha_2$}
\put(-15,-71){\small$\alpha_1$}
\put(-50,-60){\small$-\alpha_1$}
\put(-47,-44){\small$2\alpha_1+\alpha_2$}
\put(-60,-10){\small$-2\alpha_1-\alpha_2$}
\end{picture}
\caption{Some roots, associated to the Cartan matrix $\left(\begin{smallmatrix}2&-2\\-1&2\end{smallmatrix}\right)$.}
\end{figure}
\end{document}
Trying to compile this produces
Argument of \@caption has an extra }
I assume this means I shouldn't use the \}
character in captions. But how can I make a matrix without one?
The actual figure is much more complicated and invokes the named packages as well as the picture
environment, which is why I included them; the image here has no mathematical meaning.
\newcommand\cartanmatrix{\ensuremath{\textstyle\big({\begin{smallmatrix}\phantom{-}2& -2 \\-1&\phantom{-}2\end{smallmatrix}}\big)}}
and then refer to it later as\cartanmatrix
. :-) – Mico Nov 10 '11 at 17:41