Problem with foreach loop in tikzpicture - undefined control sequence

Question

I am puzzled by something in tikzpicture. Here is the problematic code that i shrinked to its minimum:

\documentclass{article}
\usepackage{tikz}
\usepackage{xcolor}
\usepackage{pgfplotstable}
\usepackage{pgfplots}
\begin{document}
\newcommand{\Table}{
\begin{tikzpicture} 
\begin{axis}
\foreach \A / \B/ \C   in {1/100/g, 2/200/h}
    \addplot [
    mark=diamond*,
    nodes near coords={g}] 
    coordinates {(\B, \A)};
\end{axis}
\end{tikzpicture}
}
\Table
\end{document}

This code works well and adds the label g next to the markers. But i would like this label to be a variable in the foreach loop. So i replace nodes near coords={g} by nodes near coords={\C}

But then I got an 'undefined control sequence' error. Could someone explain why is this the case? And also possible way to fix it?

Thanks in advance.

Answer 1

Adaptations

• The node is drawn later and then \C will be unknown. Therefore, you can use the option visualization depends on:

  visualization depends on={value \C\as\myC},
  nodes near coords={\myC}
  

  • I found the solution in this answer.
• Implemented suggestions from Jasper Habicht's comment

Code

\documentclass{article}
\usepackage{pgfplotstable}
\pgfplotsset{compat=1.18}
\begin{document}
\newcommand{\Table}{
    \begin{tikzpicture} 
        \begin{axis}
            \foreach \A / \B / \C in {1/100/g, 2/200/h}
                \addplot[
                    mark=diamond*,
                    visualization depends on={value \C\as\myC},
                    nodes near coords={\myC}
                ] 
                coordinates {(\B, \A)};
        \end{axis}
    \end{tikzpicture}
}
\Table
\end{document}

Result