amsmathhorizontal alignmentmatrices
I'm trying to typeset two matrices side by side, somewhat like:
A = (matrix) B = (matrix)
I tried to next the matrices inside an align environment:
\begin{align*}
A &= \begin{pmatrix} ... \end{pmatrix} &
B &= \begin{pmatrix} ... \end{pmatrix}
\end{align*}
but I get when compiling:
Package amsmath Error: Erroneous nesting of equation structures
Presumably the way I'm trying to do it isn't the right way; how should I be doing this?
You may want to take a look at easybmat:
\documentclass{article}
\usepackage{easybmat}
%\usepackage{etex} % if you also want tikz, then you also need etex,
%\usepackage{tikz} % and they have to be loaded AFTER easybmat
\newenvironment{bvec}[1]{\begin{BMAT}(r)[0pt]{c}{#1}}{\end{BMAT}}
\newenvironment{pbvec}[1]{\left(\begin{bvec}{#1}}{\end{bvec}\right)}
\begin{document}
$span \{
\begin{pbvec}{ccccc} 1 \\ \vdots \\ \vdots \\ 1 \\ 1 \end{pbvec},
\begin{pbvec}{ccccc} 0 \\ 1 \\ \vdots \\ \vdots \\ 1 \end{pbvec},
\begin{pbvec}{ccccc} 0 \\ 0 \\ 1 \\ \vdots \\ 1 \end{pbvec}
\begin{bvec}{ccccc} \cdots \\ {} \\ \ddots \\ \ddots \\ \cdots \end{bvec}
\begin{pbvec}{ccccc} 0 \\ \vdots \\ \vdots \\ 0 \\ 1 \end{pbvec}
\}$
\end{document}
which results in
There are a few annoying things with BMAT:
{} in the fourth line).\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{gather*}
\mbox{\scriptsize%
$A = \begin{bmatrix} a & b & c \\ d & e & f \\ g & h & i \end{bmatrix}$}\\
A = \begin{bmatrix} a & b & c \\ d & e & f \\ g & h & i \end{bmatrix}
\end{gather*}
\end{document}
Best Answer
The error has been caused by accidentally nesting
align*andequation, as Ben informed.Displayed math environments cannot be nested. However, there are environments such as
alignedandsplitwhich work inside anequationenvironment.This answer has been posted and marked as community wiki, in the hope that after an upvote this question isn't marked as "unanswered" by the site any more.