Hi Mike,
Your observation is correct: colorbar sampled simply changes the way the
colorbar is displayed; it does not control the way colors are mapped
into the colormap.
This is actually unsupported and would need to become a feature request.
What you can use is to employ the low-level interface for scatter plots
to write such stuff on your own.
A related application can be found in the pgfplots manual (search for
"Low-Level scatter plot interface Example"). Please refer to that
section to see if that is something for you. For your convencience, here
is a copy of the mentioned example (the manual contains explanations):
\begin{tikzpicture}
% Low-Level scatter plot interface Example:
% use three different marker classes
% 0% - 30% : first class
% 30% - 60% : second class
% 60% - 100% : third class
\begin{axis}[
scatter/@pre marker code/.code={%
\ifdim\pgfplotspointmetatransformed pt<300pt
\def\markopts{mark=square*,fill=blue}%
\else
\ifdim\pgfplotspointmetatransformed pt<600pt
\def\markopts{mark=triangle*,fill=orange}%
\else
\def\markopts{mark=pentagon*,fill=red}%
\fi
\fi
\expandafter\scope\expandafter[\markopts]
},%
scatter/@post marker code/.code={%
\endscope
}]
\addplot+[scatter,scatter src=y,
samples=40]
{sin(deg(x))};
\end{axis}
\end{tikzpicture}
Kind regards
Christian
Am 29.03.2013 12:58, schrieb Mike Hettich:
> Dear all,
>
> I hevaily use pgfplots for preparing graphs. I encountered a problem I
> was not able to solve yet. While it is possible to use the key "sampled"
> for the colorbar the respective data points in the plot are still
> linearly mapped onto the provided colormap. I have not found an option
> yet to force a discrete colormapping for the scatter plot, i.e. one
> color for a range of values instead of color interpolation. I hope you
> can provide some advice on how to solve this issue.
>
>
> Best regards
> Mike
>
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Own the Future-Intel(R) Level Up Game Demo Contest 2013
Rise to greatness in Intel's independent game demo contest. Compete
for recognition, cash, and the chance to get your game on Steam.
$5K grand prize plus 10 genre and skill prizes. Submit your demo
by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2
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