I am searching for a macro which prints the current x-unit-length. For instance the following document:
\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}[x=2cm,y=3cm]
\node at (0,0) {};
\end{tikzpicture}
\end{document}
Now I want a macro which can return the '2cm' of 'x' or '3cm' of y.