General ⇒ Curly braces part way alongside a matrix?

[susan_in_california]

Hello, everyone! I would very much like to represent a matrix in block gauss-jordan form. I'd like it to have the block A in the upper right, the block B in the middle and the block C on the side.

And on the left hand side, I would like to indicate with a curly brace that the block A takes a rows, the block B takes b rows, and the block C takes c rows.

It is these "partial" curly braces that are really throwing me... any ideas from anyone would be *extremely* appreciated!

Best,
Susan

[gmedina]

One possibility is to use 3 matrices: the leftmost one will contain the information about the number of rows; the middle one will contain the braces and the rightmost one will be the actual block matrix.

I used the easybmat package, since I find it particularly useful to build block matrices. Refer to the package documentation.

Code: Select all

\documentclass{article}
\usepackage{easybmat}
\usepackage{amsmath}

\begin{document}

\[ 
   \begin{BMAT}(r)[4pt,0pt,3cm]{c}{ccc}
     a \text{ rows} \\ 
     b \text{ rows} \\
     c \text{ rows}
   \end{BMAT}
   \begin{BMAT}(r)[-2pt,0pt,3cm]{c}{ccc}
     \left\lbrace \vphantom{\rule{1mm}{14pt}} \right. \\ 
     \left\lbrace \vphantom{\rule{1mm}{14pt}} \right. \\ 
     \left\lbrace \vphantom{\rule{1mm}{14pt}} \right. 
   \end{BMAT}
   \left[
   \begin{BMAT}(e)[2pt,3cm,3cm]{c.c.c}{c.c.c}
      0 & 0 & A \\ 
      0 & B & 0 \\ 
      C & 0 & 0  
   \end{BMAT}
   \right]
\] 

\end{document}

Of course, you can now adapt my example according to your needs.

[propell]

One resource I use a lot when typesetting mathematics is Herbert Voss' mathmode document:
http://tug.ctan.org/tex-archive/info/ma ... thmode.pdf

It is a comprehensive review of mathematics in (La)TeX and it contains many useful examples.

- Kjell Magne Fauske

[susan_in_california]

Thank you so much for such a nice example! That is some *beautiful* latex!

Best,
Susan