Relative coordinates do not work inside axis environment

[wehro]

The line in the first picture points 3 cm to the right as expected. The line in the second picture points 4 cm to the right and 1 cm to the up, which is wrong.

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}

\begin{document}
\begin{tikzpicture}
\draw (2,1)--+(3,0);
\end{tikzpicture}

\begin{tikzpicture}
\begin{axis}[xmin=-1,xmax=7,ymin=-1,ymax=4]
\draw (2,1)--+(3,0);
\end{axis}
\end{tikzpicture}
\end{document}

[hmenke]

I think you explicitly need axis direction cs: for relative coordinates. Please have a look in the manual.

[hmenke]