Scaled TikZ matrix of nodes

Question

So that I have a better idea of my students' names I would like to generate schematic plans of the classrooms I teach in so that the students can tick off where they are sitting. Using some ideas from here I have come up with the seating grid with aisles greyed out (see below).

I would now like to make it proportional to the rooms dimensions to make it a bit more realistic. For example, if the classroom dimensions are 6m x 12m and the open area at the top of the room is 4m then I would like to scale my seating matrix to fit into the 6m x 8m area within a drawn rectangle of 6m x 12m.

I would be very grateful for any help with this. I can then decorate the room outline with teacher's desk, podium, doors, etc.

Many thanks, Patrick Healy

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{matrix}
\begin{document}
\tikzset{myset/.style args = {(#1,#2)}{%
    row #1 column #2/.style={nodes={circle,fill=gray}}}}
\begin{tikzpicture}[myset/.list={(1,3),(1,4),(2,3),(2,4),(3,3),(3,4),
    (4,3),(4,4),(5,3),(5,4),(6,3),(6,4),(7,3),(7,4),
    (8,3),(8,4),(8,1),(8,2),(8,3),(8,4),(8,5),(8,6),(8,7),(8,8)}]
\matrix [matrix of nodes, column sep=1mm, row sep=1mm, nodes={circle,draw}]
{
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\ 
  };
\end{tikzpicture}
\end{document}

Answer 1

Maybe this scalerel/stackengine approach can be made to work for you. Here, I scale the tikzpicture (stored in temporary \box0) to 8cm (7.5 cm actually) and use \stackinset to place it and other stuff (\desk, \board, & \lectern) in the 6cm x 12cm \room.

\documentclass{standalone}
\usepackage{tikz,scalerel,stackengine}
\setstackgap{S}{0pt}
\usetikzlibrary{matrix}
\setlength\unitlength{1cm}
\begin{document}
\tikzset{myset/.style args = {(#1,#2)}{%
    row #1 column #2/.style={nodes={circle,fill=gray}}}}%
\setbox0=\hbox{\begin{tikzpicture}[myset/.list={(1,3),(1,4),(2,3),(2,4),(3,3),(3,4),
    (4,3),(4,4),(5,3),(5,4),(6,3),(6,4),(7,3),(7,4),
    (8,3),(8,4),(8,1),(8,2),(8,3),(8,4),(8,5),(8,6),(8,7),(8,8)}]
\matrix [matrix of nodes, column sep=1mm, row sep=1mm, nodes={circle,draw}]
{
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\
  {}& {}& {}& {}& {}& {}& {}& {}\\ 
  };
\end{tikzpicture}}%
\savestack\studentdesks{\scaleto{\copy0}{7.5cm}}
\def\room{\rule{6cm}{0pt}\rule{0pt}{12cm}}%
\def\desk{\framebox(2.5,1.5){desk}}%
\def\lectern{\framebox(1,1){\tiny podium}}%
\def\board{\framebox(4,.2){\tiny board}}%
%
\stackinset{c}{}{t}{}{\board}{%
\stackinset{r}{.5cm}{t}{2.5cm}{\lectern}{%
\stackinset{l}{.5cm}{t}{1cm}{\desk}{%
\stackinset{c}{}{b}{}{\studentdesks}{%
  \room}}}}%
\end{document}