Setting the name of matrix in tikz-cd

Question

tikz-cd wraps matrix creation as follows

\def\tikzcd@[#1]{%
  \tikzpicture[/tikz/commutative diagrams/.cd,every diagram,#1]%
  % ...
  \matrix[%
    % ...
    ]%
  \bgroup}

As such, there seems no way to name the matrix as created by the tikzcd environment. Is there a way to name the matrix, and still using the tikzcd environment?

The question arises out of the need to name cells of matrices. With the name of a matrix known, the cells could be conveniently referred to as name-1-1, for example.

score 13 · Accepted Answer · answered Dec 08 '17 at 09:11

13

The name is already set and can be retrived from the macro \tikzcdmatrixname. To further draw over your tikzcd matrix use execute at end picture.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{cd}
\begin{document}

\begin{tikzcd}[execute at end picture={
    \filldraw[red] (\tikzcdmatrixname-1-1) circle[radius=1pt];
    \filldraw[blue] (\tikzcdmatrixname-1-2) circle[radius=1pt];
    \filldraw[green] (\tikzcdmatrixname-2-1) circle[radius=1pt];
    \filldraw[orange] (\tikzcdmatrixname-2-2) circle[radius=1pt];
  }]
  A \ar[r]\ar[d] & B \ar[d] \\
  C \ar[r]       & D \\
\end{tikzcd}

\end{document}

answered Dec 08 '17 at 09:11

Henri Menke

109,596

2

+1! Where can it be found in tikz-cd documentation? I searched but I didn't find it. – CarLaTeX Dec 08 '17 at 09:21
@CarLaTeX I was reading the source and found \global\let\tikzcdmatrixname\tikzlastnode in there i.e. it is not documented. The execute at end picture trick on the other hand is documented. – Henri Menke Dec 08 '17 at 09:22
I'll write to the authors asking to document \tikzcdmatrixname, thank you! – CarLaTeX Dec 08 '17 at 09:24
Nice the increasing string sizes: 3,4,5,6 to produce the diagonal alignment of node code. -) – Sigur Mar 01 '19 at 14:51
This solution just saved me a lot of editing. Thank you! – David Poxon Feb 16 '20 at 00:27

CarLaTeX · Answer 2 · 2017-12-22T16:49:58.040

The author of tikz-cd himself in person (Florêncio Neves) suggested to me to use every matrix/.append style={name=...} (don't forget the append, see Torbjørn T.'s answer here). This way you could name your matrix as you wish.

I also think it's possible to use remember picture and overlay instead of execute at end picture. Here an MWE with both cases:

\documentclass{article}
\usepackage{tikz-cd}

\begin{document}
\begin{tikzcd}[every matrix/.append style={name=mycd}, 
    execute at end picture={
    \filldraw[red] (mycd-1-1) circle[radius=1pt];
    \filldraw[blue] (mycd-1-2) circle[radius=1pt];
    \filldraw[green] (mycd-2-1) circle[radius=1pt];
    \filldraw[orange] (mycd-2-2) circle[radius=1pt];
    }]
    A \ar[r]\ar[d] & B \ar[d] \\
    C \ar[r]       & D 
\end{tikzcd}%

\begin{tikzcd}[every matrix/.append style={name=mycd}, remember picture]
    A \ar[r]\ar[d] & B \ar[d] \\
    C \ar[r]       & D 
\end{tikzcd}%
\begin{tikzpicture}[overlay, remember picture]
    \filldraw[red] (mycd-1-1) circle[radius=1pt];
    \filldraw[blue] (mycd-1-2) circle[radius=1pt];
    \filldraw[green] (mycd-2-1) circle[radius=1pt];
    \filldraw[orange] (mycd-2-2) circle[radius=1pt];
\end{tikzpicture}
\end{document}

Setting the name of matrix in tikz-cd

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