How to create angular matrix with rectangle as borders

Question

I would like to replicate a matrix like this:

angular matrix

A matrix with straight horizontal and vertical lines forming a rectangle around its content.

I tried using array environment with hlines

$$
\begin{array}{c|cccccccc|}
      & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \\
    \hline
    a & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    b & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    c & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    d & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    e & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    \hline
\end{array}
$$

but got this intead:

wrong matrix

Is it possible to do it in latex or do i need an external program to generate such picture and insert it?

Torbjørn T. · Accepted Answer · 2016-05-08T11:51:37.917

4

You can of course do this with LaTeX. To generate a horizontal line that spans a subset of the columns, use \cline{x-y}, where makes a rule from column x to column y.

To remove the vertical bars from the top row you need to override the column specification for two of the cells with \multicolumn. The syntax is \multicolumn{<number of columns>}{<column specifier>}{<cell content>}. The first and last column have c| as column specifier, using \multicolumn{1}{c}{} in the first cell changes that to c without the vertical bar.

Finally, don't use $$ .. $$ for display math in LaTeX, it is recommended to use \[ \] instead.

\documentclass[a4paper]{article}
\usepackage[czech,english]{babel}
\begin{document}
\[
\shorthandoff{-}
\begin{array}{c|cccccccc|}
  \multicolumn{1}{c}{}    & 1 & 2 & 3 & 4 & 5 & 6 & 7 &   \multicolumn{1}{c}{8} \\
    \cline{2-9}
    a & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    b & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    c & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    d & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    e & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
    \cline{2-9}
\end{array}
\]
\end{document}

edited May 08 '16 at 11:51

answered May 08 '16 at 11:14

Torbjørn T.

206,688

Error: Paragraph ended before @cline was complete. – Youda008 May 08 '16 at 11:37
@Youda008 My code does not produce that error, so you must have modified it somehow. I don't know what would cause that error to show, perhaps \cline{2-9, i.e. without the closing brace. – Torbjørn T. May 08 '16 at 11:43
Something is changing meaning of symbol '-'. Probably caused by \usepackage[czech,english]{babel} – Youda008 May 08 '16 at 11:48
Adding \catcode`-=12 at the beginning of math environment is the solution. – Youda008 May 08 '16 at 11:50
Or \shorthandoff{-} in a useful place, see edited answer. – Torbjørn T. May 08 '16 at 11:52
1

See Slovak (and Czech) babel gives problems with cmidrule and cline for the problem of \cline and babel-czech – egreg May 08 '16 at 12:37
@egreg Thanks! Not surprised it has been asked about before. – Torbjørn T. May 08 '16 at 12:43

score 3 · Answer 2 · answered May 08 '16 at 11:27

Here's a code. Don't use $$ … $$ for displaymah, but \[ … \]. I loaded the array package to have some more functionalities (less tight vertical spacing, and a simpler code for repetition of cells with the same specifier):

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

\begin{document}

\[ \setlength\extrarowheight{2pt}\begin{array}{c|*{8}{c}|}
  \multicolumn{1}{c}{} & \mathbf{1} & \mathbf{2} & \mathbf{3} & \mathbf{4} & \mathbf{5} & \mathbf{6} & \mathbf{7 }& \multicolumn{1}{c}{\mathbf{8}} \\
  \cline{2-9}
  \mathbf{a} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
  \mathbf{b} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
  \mathbf{c} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
  \mathbf{d} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
  \mathbf{e} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
  \cline{2-9}
  \end{array} \]%

\end{document}

score 3 · Answer 3 · answered Nov 11 '23 at 17:11

3

With {NiceMatrix} of nicematrix.

\documentclass{article}
\usepackage{nicematrix}
\begin{document}
[\begin{NiceMatrix}
      & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & \
    a & \Block[draw]{5-8}{}
        0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \
    b & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \
    c & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \
    d & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \
    e & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \
\end{NiceMatrix}]
\end{document}

answered Nov 11 '23 at 17:11

F. Pantigny

40,250

It even works out of the box with babel-czech! – egreg Nov 11 '23 at 22:21

score 2 · Answer 4 · answered Nov 11 '23 at 21:50

What we can do in OpTeX:

\table{($)c($)|8c|}{
  \mspan1[c]{}  & 1 & 2 & 3 & 4 & 5 & 6 & 7 & \mspan1[c]{8} \crlp{2-9}
              a & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \cr
              b & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \cr
              c & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \cr
              d & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \cr
              e & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \crlp{2-9}
}
\bye

score 1 · Answer 5 · answered May 08 '16 at 12:46

A solution with \tikzmark:

\documentclass[a4paper]{article}
\usepackage[czech]{babel}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{tikzmark}

\begin{document}
\[
\begin{tikzpicture}[remember picture,overlay]
\draw ([yshift=1.2\ht\strutbox,xshift=-3pt]{pic cs:start}) 
  rectangle ([xshift=3pt,yshift=-\dp\strutbox]{pic cs:end});
\end{tikzpicture}
\begin{matrix}
& \mathbf{1} & \mathbf{2} & \mathbf{3} & \mathbf{4}
& \mathbf{5} & \mathbf{6} & \mathbf{7} & \mathbf{8}\\
\mathbf{a} & 
  \tikzmark{start}
  0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
\mathbf{b} &
  0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
\mathbf{c} &
  0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
\mathbf{d} &
  0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
\mathbf{e} &
  0 & 0 & 0 & 0 & 0 & 0 & 0 & 0
\tikzmark{end}
\end{matrix}
\]
\end{document}

Note that this requires two passes when the matrix changes, in order to be properly typeset.

How to create angular matrix with rectangle as borders

5 Answers5