[Tex/LaTex] How to get the explanation borders with pmatrix

Question

I have asked this question in chat. How can I add the explanation borders to the below matrix?

\begin{align*} 
C_{D_{1\succ 2}, \mathrm{increasing}}    &= \underbrace{\begin{pmatrix} 1   &   -1  &   1 & -1  &   1   &   -1 &    1 & -1  \\ \end{pmatrix}}_{1\times 8\text{ matrix}}  \\ 
A_{D_{1\succ 2}, \mathrm{increasing}}    &= 
\underbrace{\begin{pmatrix} 
1   &   0   &   1   &   0   &   1   &   0   &   1   &   0   \\ 
0   &   1   &   0   &   1   &   0   &   1   &   0   &   1   \\ 
1   &   1   &   0   &   0   &   1   &   1   &   0   &   0   \\ 
0   &   0   &   1   &   1   &   0   &   0   &   1   &   1   \\ 
1   &   1   &   1   &   1   &   0   &   0   &   0   &   0   \\ 
1   &   1   &   1   &   1   &   0   &   0   &   0   &   0   \\ 
0   &   0   &   0   &   0   &   1   &   1   &   1   &   1   \\ 
\end{pmatrix}}_{7\times 8 \text{ matrix}}. 
\end{align*}

I want this kind of $p_1, p_2, …$ borders to the matrix above. I have been able to add them with blockarray and block here but now I need to add them to the existing pmatrix data-structure. How can I get it with the pmatrix?

Answer 1

You can use the kbordermatrix package which is for some reason not CTAN but you can download it from http://www.hss.caltech.edu/~kcb/LaTeX.shtml and there is a short documentation there too. Just save the .sty file to the same folder with your actual document.

\documentclass{article}
\usepackage{mathtools,kbordematrix}


\begin{document}

% Change the default brackets to parentheses
\renewcommand{\kbldelim}{(}
\renewcommand{\kbrdelim}{)}
\[
\underbrace{\kbordermatrix{
    & t_1& t_2  &\cdots & t_n & \cdots & t_h &\cdots & t_{2^n}\\
p_1 &   1   &   0   &   1   &   0   &   1   &   0   &   1   &   0   \\ 
p_2 &   0   &   1   &   0   &   1   &   0   &   1   &   0   &   1   \\ 
p_3 &   1   &   1   &   0   &   0   &   1   &   1   &   0   &   0   \\ 
p_4 &   0   &   0   &   1   &   1   &   0   &   0   &   1   &   1   \\ \hline
p_5 &   1   &   1   &   1   &   1   &   0   &   0   &   0   &   0   \\ 
p_6 &   1   &   1   &   1   &   1   &   0   &   0   &   0   &   0   \\ 
p_7 &   0   &   0   &   0   &   0   &   1   &   1   &   1   &   1   \\ 
}}_{7\times 8 \text{ matrix}}
\]
\end{document}