Debugging pgf-math

Question

Just learned about pgfmath, but how can I debug it?

\pgfmathparse{..} \pgfmathresult

doesn't print anything inside a tikzpicture environment. How can I simply print the result of an expression to check weather the calculation was done correctly?

Answer 1

Christoph mentioned this but it's worth making explicit. If you don't want to actually draw anything you don't need a tikzpicture environment and you don't need to put \pgfmathresult in nodes.

\documentclass{article}
\usepackage{pgf}
\begin{document}
\pgfmathparse{2+3}
\pgfmathresult
\end{document}

Answer 2

If you want to "just print out the result", you don't need to use pgfmath inside a tikzpicture. If you want to place the result in a picture, put it into a node:

\documentclass{article}

\usepackage{tikz}

\begin{document}
 2 + 3 = \pgfmathparse{2+3}\pgfmathresult\\
 \begin{tikzpicture}
  \node at (0,0) {2 + 2 = \pgfmathparse{2+2}\pgfmathresult};
 \end{tikzpicture}

\end{document}

Note: Calculating the value before placing the node will not work, because the placing the node will overwrite the old result.

Answer 3

You don't need to launch pgf completely

\documentclass{article} 
\input{pgfutil-common.tex}
\usepackage{pgfkeys,pgfmath}
\begin{document}
\pgfmathparse{2+3*2}
\pgfmathresult
\end{document}

Answer 4

If you have to do the math in tikzpicture, you can also use \show\pgfmathresult to display the result in the console.