40

I have a matrix shown below. I would like to have the whole row green rather than only the cells.

How can I do that?

\begin{equation}\label{eq:appendrow}
\newcommand\x{\times}
\newcommand\y{\colorbox{mygreen}{$1$}}
  \left(\begin{array}{cccc}
    \x  & \x  & \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    \y  & \y  & \y & \y \\
  \end{array}\right)
\end{equation}

The output is:

enter image description here

0

7 Answers 7

47

You can use \rowcolor, \columncolor, and \cellcolor from the colortbl package, loaded in my example through the xcolor package:

\documentclass{article}
\usepackage{amsmath}
\usepackage[table]{xcolor}

\newcommand\x{\times}
\newcommand\y{\cellcolor{green!10}}

\begin{document}

\begin{equation}\label{eq:appendrow}
  \left(\begin{array}{cccc}
    \rowcolor{red!20}
    \x  & \x  & \x & \x \\
    0   & \x  & \x & \x \\
   \rowcolor{blue!20}
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    \y a  &  b  & \y c &  d\\
  \end{array}\right)
\end{equation}

\begin{equation}
  \left(\begin{array}{>{\columncolor{olive!20}}cc>{\columncolor{yellow!20}}cc}
    \x  & \x  & \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    a  & b  & c & d \\
  \end{array}\right)
\end{equation}

\end{document}

enter image description here

2
  • 2
    Muchisimas gracias! :)
    – SkyWalker
    Sep 1, 2012 at 19:43
  • Is there a way to do this for diagonals as well? Jan 10, 2021 at 16:14
15

Another approach could be using the hf-tikz package.

Example:

\documentclass{article}
\usepackage{amsmath}

\newcommand\x{\times}

% requires version 0.3 of the package
\usepackage[customcolors]{hf-tikz}

\tikzset{style green/.style={
    set fill color=green!50!lime!60,
    set border color=white,
  },
  style cyan/.style={
    set fill color=cyan!90!blue!60,
    set border color=white,
  },
  style orange/.style={
    set fill color=orange!80!red!60,
    set border color=white,
  },
  hor/.style={
    above left offset={-0.15,0.31},
    below right offset={0.15,-0.125},
    #1
  },
  ver/.style={
    above left offset={-0.1,0.3},
    below right offset={0.15,-0.15},
    #1
  }
}

\begin{document}

\begin{equation}\label{eq:appendrow}
  \left(\begin{array}{cccc}
    \x  & \x  & \x & \x \\
    0   & \tikzmarkin[hor=style orange]{el} \x  & \x\tikzmarkend{el} & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    \tikzmarkin[hor=style green]{row} a  &  b  &  c &  d \tikzmarkend{row}\\
  \end{array}\right)
\end{equation}

\begin{equation}\label{eq:appendcol}
  \left(\begin{array}{cccc}
    \tikzmarkin[ver=style cyan]{col 1}\x  & \x  & \tikzmarkin[ver=style green]{col 2} \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
   0   & 0   & 0  & \x \\
    a \tikzmarkend{col 1}  &  b  &  c  \tikzmarkend{col 2} &  d \\
  \end{array}\right)
\end{equation}

\end{document}

Result:

enter image description here

2
  • @Sebastiano: with TeXLive 2019 I have no compilation errors nor warning messages. Jul 30, 2019 at 6:54
  • Claudio excuse me very much for my comment that I have deleted. Probabily using Papeeria Live demo online I have setteed TeXLive 2015 as default. Excuse me. My best regards.
    – Sebastiano
    Jul 30, 2019 at 14:49
8

Within {pNiceMatrix} of nicematrix, you have a command \Block which may be used for highlighting a part of the matrix.

\documentclass{article}
\usepackage{nicematrix}

\begin{document}

$\begin{pNiceMatrix}[margin]
a & b & c & d \\
\Block[fill=red!15,rounded-corners]{1-4}{}
a & b & c & d \\
a & b & c & d \\
a & b & \Block[draw,fill=blue!15,rounded-corners]{2-2}{}
        c & d \\
a & b & c & d \\
\end{pNiceMatrix}$

\end{document}

You need several compilations (because nicematrix uses PGF/Tikz nodes under the hood).

Output of the above code

5

I wanted to answer this post: how to obtain vertical and horizontal gray bars in a matrix? but it was closed as a duplicate of the one I'm answering now.

However, since here there's no a solution with a TikZ matrix yet:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix, fit}
\usetikzlibrary{backgrounds}
\newcommand\x{\times}

\begin{document}
\begin{tikzpicture}
    \matrix[
        matrix of math nodes,
        row sep=.5ex,
        column sep=.5ex,
        left delimiter=(,right delimiter=),
        nodes={text width=.75em, text height=1.75ex, text depth=.5ex, align=center}
        ] (m) 
        {
        \x & \x & \x & \x \\
        0  & \x & \x & \x \\
        0  & 0  & \x & \x \\
        0  & 0  & 0  & \x \\
        1  & 1  & 1  & 1 \\
        };
        \begin{scope}[on background layer]
            \node[fit=(m-2-1)(m-2-4), draw=green!30, fill=green!30, rounded corners] {};
            \node[fit=(m-1-3)(m-5-3), draw=green!30, fill=green!30, rounded corners] {};
            \node[fit=(m-2-3), fill=green] {};
        \end{scope} 
\end{tikzpicture}
\end{document}

enter image description here

Alternatively, a solution like Zarko's answer, with rounded corners:

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{matrix}
\usetikzlibrary{backgrounds}
\newcommand\x{\times}

\begin{document}
\begin{tikzpicture}
\matrix [matrix of math nodes,
         nodes={rectangle, 
                minimum size=1.2em, text depth=0.25ex,
                inner sep=0pt, outer sep=0pt,
                anchor=center},
         column sep=-0.5\pgflinewidth,
         row sep=-0.5\pgflinewidth,
         inner sep=0pt,
         left delimiter=(, right delimiter=),
         row 2 column 2/.append style={nodes={draw=cyan,fill=cyan}},
         ] (m)
{
a_1 & \x  & a_3 \\
a_4 & \x  & a_6 \\
a_7 & \x  & a_9 \\
};
\begin{scope}[on background layer]
    \filldraw[cyan!50, rounded corners] (m-2-1.north west) -- 
        (m-2-1.south west) -- (m-2-3.south east)-- (m-2-3.north east)-- 
        cycle;
    \filldraw[cyan!50, rounded corners] (m-1-2.north west) -- 
        (m-3-2.south west) -- (m-3-2.south east)-- (m-1-2.north east)-- 
        cycle;
\end{scope} 
\end{tikzpicture}
\end{document}

enter image description here

7
  • testing your nice solution (+1), i discover interesting "malfunction" of matrix of math nodes: if i use minimum size=... instead of text width=..., text height=... i receive error: missing $ ... now i wonder why. i will try to investigate this more.
    – Zarko
    Feb 17, 2018 at 21:58
  • i test simple example based on example in tikz & pgf manual, page 647, third example, and there i don't receive any error. now i will look closely, what is in your code different to my example.
    – Zarko
    Feb 17, 2018 at 22:08
  • no, i didn't. i will give more attention to this problem tomorrow.
    – Zarko
    Feb 17, 2018 at 22:59
  • i found cause of problem: if i comment line left delimiter=(, right delimiter=),, than my experiment works, however, with this delimiters are lost:-(
    – Zarko
    Feb 17, 2018 at 23:27
  • about this problem i ask new question: tex.stackexchange.com/questions/415877/…
    – Zarko
    Feb 17, 2018 at 23:47
3

if the rounded border of bars is not essential, than an alternative to CarLaTeX answer, which is used as base in preparing mine, is:

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{matrix}
\newcommand\x{\times}

\begin{document}
\begin{tikzpicture}
\matrix [matrix of math nodes,
         nodes={rectangle, %draw, very thin,
                minimum size=1.2em, text depth=0.25ex,
                inner sep=0pt, outer sep=0pt,
                fill opacity=0.5, text opacity=1,
                anchor=center},
         column sep=-0.5\pgflinewidth,
         row sep=-0.5\pgflinewidth,
         column 2/.append style = {nodes={fill=cyan!50}},
         row 2/.append style = {nodes={fill=cyan!50}},
         row 2 column 2/.append style={nodes={fill=cyan}},
         inner sep=0pt,
         left delimiter=(, right delimiter=),
         ]
{
a_1 & \x  & a_3 \\
a_4 & \x  & a_6 \\
a_7 & \x  & a_9 \\
};
\end{tikzpicture}
\end{document}

(well, matrix is not original but from some my experiments), which gives:

enter image description here

addendum: above answer contain some wrong assumptions: (i) how transparency work (on level of nodes it hasn't any sense, so better is not use it on such way); (ii) transparency had to be resolved on row 2 and column style definition (see mwe below) ; (iii) nodes with only fill should not overlap each other for edge lines width, so the sep=-0.5\pgflinewidth, row sep=-0.5\pgflinewidth had to be removed; (iv) from comparison of nodes definition in CarLaTeX answer and mine i recently observe important difference: nodes={text width=.75em, text height=1.75ex, text depth=.5ex, align=center} but i try to use in form nodes={minimum size=1.75ex, text depth=.5ex, align=center} where align=center cause error (removing it remove the error).

for comparison i left first mwe above as it is. corrected one is:

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{matrix}
\newcommand\x{\times}

\begin{document}   
\begin{tikzpicture}
\matrix [matrix of math nodes,
         nodes={rectangle,
                minimum size=1.5em, text depth=0.25ex,
                inner sep=0pt, outer sep=0pt,
                anchor=center},
         row 2/.append style = {nodes={preaction={fill=cyan!30}}},
         column 2/.append style = {nodes={fill=red!60},fill opacity=0.5, text opacity=1},
         inner sep=0pt,
         left delimiter=(, right delimiter=),
         ]
{
a_1 & \x  & a_3 \\
a_4 & \x  & a_6 \\
a_7 & \x  & a_9 \\
};
\end{tikzpicture}
\end{document}

which gives:

enter image description here

3

An alternative solution with tblr environment of tabularray package:

\documentclass{article}

\usepackage{amsmath}
\usepackage{xcolor}

\usepackage{tabularray}
\SetTblrInner{colsep=5pt,rowsep=1pt}

\newcommand\x{\times}

\begin{document}

\begin{equation}\label{eq:appendrow}
  \left(\begin{tblr}{
    colspec = {cccc},
    row{1} = {red9},
    row{3} = {blue9},
    cell{5}{1,3} = {green9},
  }
    \x & \x & \x & \x \\
     0 & \x & \x & \x \\
     0 &  0 & \x & \x \\
     0 &  0 &  0 & \x \\
     a &  b &  c &  d \\
  \end{tblr}\right)
\end{equation}

\begin{equation}
  \left(\begin{tblr}{Q[c,olive9]cQ[c,yellow9]c}
    \x & \x & \x & \x \\
     0 & \x & \x & \x \\
     0 &  0 & \x & \x \\
     0 &  0 &  0 & \x \\
     a &  b &  c &  d \\
  \end{tblr}\right)
\end{equation}

\end{document}

enter image description here

1

Thank you for your answer. I would like to share that tip. First I will explain the problem, and after that, I will post the solution.

PROBLEM

If I do that:

    \begin{equation}\label{eq:appendcol}
  \left(\begin{array}{cccc}
    \tikzmarkin[ver=style red]{col 1}\x  & \x  & \tikzmarkin[ver=style red]{col 2} \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    a \tikzmarkend{col 1}  &  b  &  c  \tikzmarkend{col 2} &  d \\
  \end{array}\right)
\end{equation}

\begin{equation}\label{eq:appendcol}
  \left(\begin{array}{cccc}
    \tikzmarkin[ver=style red]{col 1}\x  & \x  & \tikzmarkin[ver=style red]{col 2} \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    a \tikzmarkend{col 1}  &  b  &  c  \tikzmarkend{col 2} &  d \\
  \end{array}\right)
\end{equation}

Vertical highlighting continues from first matrix to second, invading the space between them. The result:

Highlight invasion between 2 matrix using tkiz

SOLUTION

\begin{equation}\label{eq:appendcol}
  \left(\begin{array}{cccc}
    \tikzmarkin[ver=style red]{col 1}\x  & \x  & \tikzmarkin[ver=style red]{col 2} \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    a \tikzmarkend{col 1}  &  b  &  c  \tikzmarkend{col 2} &  d \\
  \end{array}\right)
\end{equation}

\begin{equation}\label{eq:appendcol-second}
  \left(\begin{array}{cccc}
    \tikzmarkin[ver=style red]{col 1-a}\x  & \x  & \tikzmarkin[ver=style red]{col 2-a} \x & \x \\
    0   & \x  & \x & \x \\
    0   & 0   & \x & \x \\
    0   & 0   & 0  & \x \\
    a \tikzmarkend{col 1-a}  &  b  &  c  \tikzmarkend{col 2-a} &  d \\
  \end{array}\right)
\end{equation}

And this is the final solution:

enter image description here

Special thanks to @percusse and @claudio-fiandrino that helped me to solve the problem on that post:

Problems with matrix highlighting in two separate equations using hf-tikz

1
  • 2
    This space is reserved for answers. If you have another question that is not answered here, please ask it by clicking the Ask Question button. Follow-up questions like this are more than welcome! You can link to this question to provide background if it helps motivate/clarify your question. Mar 10, 2015 at 21:38

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