Irregular Chessboard and Labels

Question

I need to type only half triangular part of a chessboard with different coloring setting and label the rows and columns not by a,b,...;1,2,... but by other letters. More explicitly, I need to type something like the following figure but I couldn't find anyway to do this with any package. Are there any simple way to do this?

chessboard is for chess, not for arbitrary collections of square fields. Use tikz for this. — Ulrike Fischer, Jul 10 '19 at 10:39
See also https://tex.stackexchange.com/questions/168281/how-to-draw-a-chessboard-with-numbers — John Kormylo, Jul 10 '19 at 12:49
There is a package called tikz based on pgf plots. You would have to read yourself into it, but trust me it is worth it! :D http://www.texample.net/tikz/ — Andreas B., Jul 10 '19 at 10:33

score 3 · Accepted Answer · answered Jul 10 '19 at 13:53

You can start from following code:

\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{matrix, positioning}

\begin{document}
\begin{tikzpicture}
\matrix (A) [matrix of nodes,
    nodes={draw, fill, minimum size=9mm}]
    {~&~&~&~&|[fill=white]|~&|[fill=white]|~&|[fill=white]|~\\
     &~&~&~&|[fill=white]|~&|[fill=white]|~&|[fill=white]|~\\
     &&~&~&|[fill=white]|~&|[fill=white]|~&|[fill=white]|~\\
     &&&~&~&~&~\\
     &&&&~&~&~\\
     &&&&&~&~\\
     &&&&&&~\\};
    \foreach \i [count=\ni from 4, count=\nj from 2] in {1,...,7}{ 
        \node[right=1mm of A-\i-7.east]{$a_{1\nj}$};
        \node[above=1mm of A-1-\i.north]{$a_{\ni(11)}$};
    }
\end{tikzpicture}
\end{document}

score 0 · Answer 2 · answered Jul 10 '19 at 15:37

Just for fun, an alternative that fills the entries programmatically.

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{matrix}
\begin{document}
\begin{tikzpicture}
\matrix[matrix of nodes,nodes in empty cells,column sep=-\pgflinewidth,row
sep=-3*\pgflinewidth,nodes={align=center,minimum width=4em,minimum height=4em,
/utils/exec=\ifnum\the\pgfmatrixcurrentcolumn<8
\ifnum\the\pgfmatrixcurrentrow>1 
 \ifnum\the\numexpr\pgfmatrixcurrentcolumn+1\relax>\the\numexpr\pgfmatrixcurrentrow-1\relax
  \ifnum\the\pgfmatrixcurrentcolumn>4
   \ifnum\the\pgfmatrixcurrentrow<5
    \tikzset{draw,fill=white}
   \else
    \tikzset{draw,fill}
   \fi
   \else
   \tikzset{draw,fill}
  \fi 
 \else
 \fi
\fi
\fi,
execute at begin node={\ifnum\the\pgfmatrixcurrentrow=1%
\ifnum\the\pgfmatrixcurrentcolumn<8% 
$a_{\the\numexpr\pgfmatrixcurrentcolumn+3\relax(11)}$%
\fi%
\else%
\ifnum\the\pgfmatrixcurrentcolumn=8% 
$a_{1\the\pgfmatrixcurrentrow}$%
\fi%
\fi%
}}] (mat)
 {& & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 & & & & & & &\\
 };
\end{tikzpicture}
\end{document}

Irregular Chessboard and Labels

2 Answers2