While loops in TikZ?

Question

Is it possible to have while loops in TikZ, or some equivalent loop which only terminates after a certain condition?

Answer 1

You can combine the loop \foreach with the provided command \breakforeach. The following example is copied from the manual.

\begin{tikzpicture}
\foreach \x in {1,...,4}
 \foreach \y in {1,...,4}
   {
    \fill[red!50] (\x,\y) ellipse (3pt and 6pt);
    \ifnum \x<\y
     \breakforeach
    \fi
   }
\end{tikzpicture}

Answer 2

Update \whiledo is defined in the package ifthen and not calc

TikZ is based on TeX also you can build a while loop with TeX but it's also possible to use different packages like ifthen. With ifthen you can use the macro \whiledo and macros from TikZ.