# Using a custom command inside Tikz-Calc

This my first question here, so I hope that I present it in an appropriate form.

At the moment I'm generating lots of schematics using the TikZ-package and it's calc-Library. Therefore I use coordinates very often and in some cases I've to set either the x-coordinate or the y-coordinate to zero. What I use so far:

([yscale=0](coordiantes))


It works flawlessly so I'd like to create a custom command for that. This works to but when I'm trying to use this custom command inside a calculation LaTeX gives me an error:


\end{tikzpicture}

\end{document}