Pgfplots contour gnuplot crazy labels

This is driving me mad. I am tryng to create some contour plots, but I get them full of labels, so that they are unreadable! I can't even see the lines or read the values because they are too much. I just formatted the numeric output from my script, so that the code I am placing here is not really nice. Anyway, I can get the right contour but I would like to have ONLY ONE label on each contour line, not N. I couldn't find any solution on pgfplots manual. Here is my code:

\begin{tikzpicture}
\begin{axis}
[xlabel=$x$,
ylabel=$y$,
width=0.48\columnwidth,
view={0}{90},
ymin=0, ymax=70
]
[contour gnuplot,
thick
]
coordinates {
.....
};
\end{axis}
\end{tikzpicture}


I did not post the coordinates because my file was more than 1000 lines. Any idea? Thanks in advance

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Generally, the PGFPlots algorithm does a pretty good job at deciding where to put the labels. If it doesn't work as you want it to, you could try setting contour/label distance to a value greater than the default of 200pt. Maybe you could try creating a smaller sample of your data that reproduces the undesired behaviour, then we could attempt a more targeted solution. –  Jake Dec 23 '12 at 19:17
The automatic label placement of pgfplots only has the label distance key to customize its result as indicated by @Jake (however, the initial value is 70pt). If you only want one label per contour line, you can set contour gnuplot={label distance=10000pt}. Pgfplots will always generate one label. You can also disable labels using contour gnuplot={labels=false}. –  Christian Feuersänger Dec 23 '12 at 19:37
that worked. Iti didn't post only one label each line but more, anyway result was much better –  fmonegaglia Dec 24 '12 at 10:35

The automatic label placement of pgfplots only has the label distance key to customize its result as indicated by @Jake (however, the initial value is 70pt).

If you only want one label per contour line, you can set contour gnuplot={label distance=10000pt}. Pgfplots will always generate one label, so this disables only the following ones.

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat = 1.7}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
title={$x \exp(-x^2-y^2)$},
domain=-2:2,enlarge x limits,
view={0}{90},
]
contour gnuplot={
number=14,
label distance=10000pt,
},
thick]
{exp(0-x^2-y^2)*x};
\end{axis}
\end{tikzpicture}

\end{document}


You can also disable labels using contour gnuplot={labels=false}.

If you believe that the outcome should be improved somehow (like "move the label somehow" or whatever), you can post feature requests at http://sourceforge.net/projects/pgfplots/ . In that case I would like to ask you to include a full phrase stating the expected behavior.

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thanks for this. On a side node, label distance=10000pt works well on closed contours. Open contours, e.g. this, makes the labels vanish outside the plot. I tried to use anchor=south west and outer xsep, but then the labels are sloped wrongly. What could I do? Should I post a question on that? –  Sebastian Mar 11 at 16:03
That could be a bug. Could you send a minimal working example by mail? My address is in the manual of pgfplots. –  Christian Feuersänger Mar 11 at 17:13