2

I would like to draw a highlighted path along elements of a matrix, as in the following example (which looks quite ugly as I drew the path manually with Gimp).

enter image description here

I know ways of changing the color of individual cells, rows and columns, but I haven't seen yet someone showing how to do such (shadow-like) highlighted paths.

Is there an easy way to do this for standard LaTeX matrices? If not, then I suppose it's not too hard with TikZ matrices? (How exactly?)

  • Please provide what you try so far, at list code of your matrix . With TikZ matrix this is not so complicated. – Zarko May 15 '16 at 18:59
  • @Zarko: I have an ordinary LaTeX matrix, and I am hoping that this is possible without TikZ matrices, as I would like to keep exactly the same look for all matrices in the text. I am using the pmatrix* environment. – Jay May 15 '16 at 19:10
5

This is slightly adopted on my old example of matrix with highlighted elements (it quit differ from your image):

enter image description here

To change path to your wish you only need to select nodes in matrix, through which path should go.

\documentclass[border=1mm]{standalone}
    \usepackage{tikz}
    \usetikzlibrary{matrix}

    \begin{document}
        \centering
\begin{tikzpicture}[
strip/.style = {
    draw=gray, rounded corners=3mm,
    line width=3mm, opacity=0.2,
    line cap=round
                },
                    ]
\matrix (M)  [matrix of math nodes,
              column sep=1em,
              nodes={text height=1ex,text width=2ex}]
{
1 &2 &3 &4 & 5 & 6  \\
1 &2 &3 &4 & 5 & 6  \\
1 &2 &3 &4 & 5 & 6  \\
1 &2 &3 &4 & 5 & 6  \\
1 &2 &3 &4 & 5 & 6  \\
1 &2 &3 &4 & 5 & 6  \\
};
\draw[strip,transform canvas={xshift=-0.5mm}]
    (M-1-1.north) -- (M-4-1.center)
                  -- (M-4-4.center)
                  -- (M-2-4.center)
                  -- (M-2-2.center) -- (M-1-2.north);
\end{tikzpicture}
    \end{document}
2

It's easy to do with pstricks, as it allows using a usual ams matrix environment. The relevant entries of the matrix are defined as \rnodes, and these nodes are connected with \ncboxes:

\documentclass{article}
\usepackage{amsmath}
\usepackage[table, x11names]{xcolor}
\usepackage{fourier}
\usepackage{pst-node, multido}
\usepackage{auto-pst-pdf}

\begin{document}

\begin{equation*}
  \begin{postscript}
    \begin{matrix}
      \rnode{A1}{1} & -1 & 3              & \rnode{A8}{8} & 10             & -5 \\
      2             & 3  & 4              & \rnode{A7}{1} & \rnode{A6}{-2} & 2  \\
      \rnode{A2}{5} & 1  & \rnode{A3}{-3} & 2             & 1              & 7  \\
      0             & 1  & 0              & 2             & -1             & 4  \\
      1             & 0  & \rnode{A4}{1}  & 0             & \rnode{A5}{-2} & 3  \\
      8             & 1  & 2              & -2            & 1              & 0
    \end{matrix}%
    \psset{boxsize=1.5ex, boxdepth=1.5ex, nodesep =0.5ex,  linestyle=none, fillstyle=solid, fillcolor=VioletRed4, opacity=0.15}
    \multido{\i=1+2, \in=2+2}{4}{\ncbox{A\i}{A\in}}
    \psset{boxsize=1.2ex, boxdepth=1.2ex,  nodesepA=0.95ex, nodesepB=0.2ex}
    \multido{\i=2+2, \in=3+2}{2}{\ncbox{A\i}{A\in}}
    \ncbox{A7}{A6}
  \end{postscript}
\end{equation*}

\end{document} 

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.