User defined path leads error when using `to` operator with trigonometric calculation

Question

I need to draw a path leaving the origin at a sight angle and reaching a desired location. Here is my code.

\begin{tikzpicture}
\def\localDistance{5}
\def\localHeight{3}
\def\sightAngle{atan(\localHeight/\localDistance)}
\draw
    (0,0) to[out=\sightAngle,in=180]
        (\localDistance,\localHeight)  node[right]{Error message rises when I set out=\textbackslash sightAngle}
    ;
\end{tikzpicture}

I get the following error message

No shape named atan(3/localDistance is known.

My question is: what am I doing wrong here?

I saw a similar issue here but at the same time totally different. I tried those suggestions, but didn't work.

Try to use \pgfmathsetmacro insread of \def for defining \sightAngle — koleygr, Oct 17 '18 at 20:05
@A.Ellet, yes! I just edited. But the problem remains. Thank you! — Brasil, Oct 17 '18 at 20:06
@koleygr thank you! It works! Can you pleas post as answer so I can mark is as the solution? — Brasil, Oct 17 '18 at 20:12

score 4 · Accepted Answer · answered Oct 17 '18 at 20:15

Use \pgfmathsetmacro to get this work properly:

\documentclass[border=6pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{tikzpicture}
\def\localDistance{5}
\def\localHeight{3}
\pgfmathsetmacro\sightAngle{atan(\localHeight/\localDistance)}
\draw
    (0,0) to[out=\sightAngle,in=180]
        (\localDistance,\localHeight)  node[right]{Error message rises when I set out=\textbackslash sightAngle}
    ;
\end{tikzpicture}
\end{document}

User defined path leads error when using `to` operator with trigonometric calculation

1 Answers1