5

I am looking for a way to circle together the red entries of the following matrix:

$$
\begin{matrix}
    \textcolor{blue}{[0,1]}      & \times & \textcolor{blue}{[0,1]} & \times & \textcolor{blue}{[0,1]}  & \times  & \textcolor{blue}{[0,1]}  & \times  & \textcolor{blue}{[0,1]} & \times & \cdots  & \times  & \textcolor{blue}{[0,1]} & \times  & \textcolor{blue}{[0,1]} & \times  & \textcolor{blue}{[0,1]} \\
    \textcolor{blue}{[2,3]}      & \times & \textbf{\textcolor{red}{[0,1]}} & \times & \textbf{\textcolor{red}{[0,1]}} & \times  & \textbf{\textcolor{red}{[0,1]}} & \times  & \textbf{\textcolor{red}{[0,1]}} & \times & \cdots  & \times  & \textbf{\textcolor{red}{[0,1]}} & \times  & \textbf{\textcolor{red}{[0,1]}} & \times  & \textbf{\textcolor{red}{[0,1]}} \\
    \textbf{\textcolor{red}{[1,2]}}      & \times & \textcolor{blue}{[2,3]} & \times & [0,1] & \times  & [0,1]  & \times  & [0,1]  & \times & \cdots  & \times  & [0,1] & \times  & [0,1] & \times  & \textbf{\textcolor{red}{[0,1]}} \\
    [1,2]      & \times &  [1,2]       & \times & \textcolor{blue}{[2,3]}  & \times  & [0,1]   & \times  & [0,1] & \times & \cdots  & \times  & [0,1]  & \times  & [0,1] & \times  & [0,1]  \\
    [1,2]       & \times &  [1,2]      & \times &  [1,2]    & \times  & \textcolor{blue}{[2,3]}  & \times  & [0,1]  & \times & \cdots  & \times  & [0,1] & \times  & [0,1] & \times  & [0,1]\\
    \vdots      & \vdots & \vdots  & \vdots & \vdots  & \vdots   & \vdots & \vdots & \vdots  & \vdots & \vdots & \vdots  & \vdots & \vdots & \vdots & \vdots & \vdots \\
   [1,2]      & \times & [1,2]    & \times &  [1,2]       & \times  &  [1,2]       & \times  &  [1,2]      & \times & \cdots  & \times  &  [1,2]     & \times  & \textcolor{blue}{[2,3]} & \times  & [0,1]\\
  [1,2]       & \times &  [1,2]     & \times &  [1,2]       & \times  &  [1,2]     & \times  &  [1,2]     & \times & \cdots  & \times  &  [1,2]     & \times  &  [1,2]     & \times  & \textcolor{blue}{[2,3]}\\
\end{matrix}.
$$

Actually, I need many circles like this: all entries before the blue entry in a line should be circled with all entries after the blue entry in the previous line. A simple thin circle would do the job. Is there a standard way of doing this?

Thanks!

PS: A picture of a possible output (simplified):

enter image description here

4

Perhaps something like this would work?

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{calc,matrix,backgrounds}

\pgfdeclarelayer{overlay}
\pgfsetlayers{overlay,background,main}

\tikzset{circle/.style = {rounded corners,line width=1bp,color=#1}}%

\begin{document}

\[
\left[
\begin{tikzpicture}[baseline=-\the\dimexpr\fontdimen22\textfont2\relax]
\matrix (m)[matrix of math nodes]
{
A & B & C & D \\ 
E & F & G & H \\ 
I & J & K & L \\
M & N & O & P\\
};
\begin{pgfonlayer}{overlay}
\draw[circle=blue] (m-2-2.north east) -- (m-2-3.north east) -- (m-2-3.south east) -- (m-3-4.north east) -- (m-3-4.south east) -- (m-3-4.south west) -- (m-2-3.south east) -- (m-2-2.south west) -- (m-2-2.north west) -- (m-2-2.north east);
\end{pgfonlayer}
\end{tikzpicture}
\right]
\]
\end{document}

enter image description here

4

Another possibility with pst-node. I slightly simplified your code:

    \documentclass[svgnames]{article}
    \usepackage{array, mathtools}
    \usepackage{pst-node, auto-pst-pdf}

    \begin{document}

     \[ \arraycolsep=1pt \setlength{\extrarowheight}{3pt}
     \begin{postscript
     \begin{array}{*{17}{c}}
     \color{blue} [0,1] & \times & \color{blue} [0,1] & \times & \color{blue} [0,1] & \times & \color{blue} [0,1] & \times & \color{blue} [0,1] & \times & \cdots & \times & \color{blue} [0,1] & \times & \color{blue} [0,1] & \times & \color{blue} [0,1] \\
     \color{blue} [2,3] & \times & \pnode[-0.3ex,2.4ex]{C} \color{red}\mathbf{[0,1]} & \times & \color{red}\mathbf{[0,1]} & \times & \color{red} \mathbf{[0,1]} & \times & \color{red} \mathbf{[0,1]} & \times & \cdots & \times & \color{red} \mathbf{[0,1]} & \times & \color{red} \mathbf{[0,1]} & \times \pnode[0.2ex,-1ex]{G} & \color{red} \mathbf{[0,1]} \pnode[0.4ex,2.4ex]{D}\\
    \pnode[-0.4ex,2.4ex]{A}\pnode[-0.4ex,-1.2ex]{L} \color{red} \mathbf{[0,1]}\pnode[0.4ex,2.4ex]{H}\pnode[0.4ex,-1.2ex]{K} &\times \pnode[0.2ex,2.4ex]{B} & \color{blue} [2,3] & \times & [0,1] & \times & [0,1] & \times & [0,1] & \times & \cdots & \times & [0,1] & \times & [0,1] & \times \pnode[0.2ex,-1ex]{F} & \color{red} \mathbf{[0,1]} \pnode[0.4ex,-1ex]{E} \\{}
     [1,2] & \times & [1,2] & \times & \color{blue} [2,3] & \times & [0,1] & \times & [0,1] & \times & \cdots & \times & [0,1] & \times & [0,1] & \times & [0,1] \\{}
     [1,2] & \times & [1,2] & \times & [1,2] & \times & \color{blue} [2,3] & \times & [0,1] & \times & \cdots & \times & [0,1] & \times & [0,1] & \times & [0,1]\\
     \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots \\{}
     [1,2] & \times & [1,2] & \times & [1,2] & \times & [1,2] & \times & [1,2] & \times & \cdots & \times & [1,2] & \times & \color{blue} [2,3] & \times & [0,1]\\{}
     [1,2] & \times & [1,2] & \times & [1,2] & \times & [1,2] & \times & [1,2] & \times & \cdots & \times & [1,2] & \times & [1,2] & \times & \color{blue} [2,3]\\
    \end{array}.
    %%
    \psline[linecolor=Crimson!60, linejoin=1,linearc=2pt](A)(B)(C)(D)(E)(F)(G)(H)(K)(L)(A)
    \end{postscript} \]%

     \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.