When I compile the following document, I get
! Undefined control sequence.
\GenericError ...
#4 \errhelp \@err@ ...
l.39 ...an, y=variance, col sep=comma] {data.csv};
^^M
?
But when I change \mathbb{R}
to mathbb{R}
everything is fine. And the document also compiles when I put $\mathbb{R}$ over the tikz picture.
What is the problem and how do I fix it?
Code
\documentclass[varwidth=true, border=2pt]{standalone}
\usepackage[utf8]{inputenc} % this is needed for umlauts
\usepackage[ngerman]{babel} % this is needed for umlauts
\usepackage[T1]{fontenc} % this is needed for correct output of umlauts in pdf
\usepackage[margin=2.5cm]{geometry} %layout
\usepackage{filecontents} % only for this question
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{pgfplots}
\pgfplotsset{compat=1.10}
\begin{document}
\begin{filecontents}{data.csv}
label,mean,variance
B,0.66,0.14
C,0.85,0.17
\pi,1.29,0.35
\mathbb{R},0.75,0.22
\end{filecontents}
\begin{tikzpicture}
\begin{axis}[
width=15cm, height=8cm,
xlabel=mean,
ylabel=variance,
visualization depends on={value \thisrow{label} \as \label},
every node near coord/.append style={font={\tiny}},
nodes near coords={$\label$},
]
\addplot[scatter,
mark=x,only marks,
mark size=1,
]
table [x=mean, y=variance, col sep=comma] {data.csv};
\end{axis}
\end{tikzpicture}
\end{document}
\noexpand\protect\noexpand
(which works).