# How can I use \pgfmathresult as x-coordinate?

I need to use \pgfmathparse{floor(\textwidth/2)} as one of x-coordinates of a path but I get an error.

\documentclass[margin=5mm,varwidth=100mm]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\path[draw](0,0)--(\pgfmathparse{floor(\textwidth/2)},0);
\end{tikzpicture}
\end{document}

• You can't use \pgfmathparse there. You are getting a bunch of errors. Put \pgfmathparse outside of the \draw command (before) then use \pgfmathresult. – Phelype Oleinik May 11 at 0:57
• There is no need to call \pfmathparse, \documentclass[margin=5mm,varwidth=100mm]{standalone} \usepackage{tikz} \begin{document} \begin{tikzpicture} \path[draw](0,0)--({floor(\textwidth/2)},0); \end{tikzpicture} \end{document} works. – user121799 May 11 at 0:58

\documentclass[margin=5mm,varwidth=100mm]{standalone}

The only thing you have to watch out for are things like the brackets, which you have to put in a braces, i.e. \path[draw](0,0)--(floor(\textwidth/2),0); will give an error because TikZ does not know which brackets delimit the coordinates. Another thing you may want to consider is that TikZ will convert these units to points. So floor may or may not give you what you want. However, you can always convert things to the units you want to work in, e.g. \path[draw](0,0)--({floor((\textwidth/2)*1pt/1cm)*1cm},0);.