# Matlab2Tikz colorbar / colormap issues

I've got some issues using the matlab2tikz script by Nico Schlömer. In Matlab I created a 3d plot including a bunch of patches. Some scalar values are highlighted using the jet colormap (see the attached *.png file).

I then translated this figure into a tikzpicture by invoking matlab2tikz('Test6.tex'). Matlab printed the information

> Found colormap/jet to be a pretty good match for your color map (||diff||=0.0280337).


Compiling the rather huge tikz file by

\usetikzlibrary{external} \tikzset{external/system call={lualatex
\tikzexternalcheckshellescape -halt-on-error
-interaction=batchmode -jobname "\image" "\texsource"}}
\tikzexternalize[prefix=autofigs/]


and

\begin{figure}[h]
\input{Bilder/Test6.tex}%
\caption{\label{fig:1}Our figure}
\end{figure}


using pdflatex produces this results (screenshot of corresponding pdf)

[

Both, the colormap and the colorbar are obviously completely different to the original plot. Can anyone help me fixing this issue?

• Judging by your description and the answer below, this sounds very much like matlab2tikz doing the wrong thing, and that is something that should be reported at github.com/matlab2tikz/matlab2tikz/issues if you haven't already. Bug reports like that are off-topic here. It would also be great if you could give some feedback to Jonas, whether his answer helped or not. (Leave a comment and/or upvote/accept.) – Torbjørn T. Sep 5 '16 at 13:33

I experienced the same issue. I think there is an error in the generation of the colormap in the matlab2tikz.m file. You will have to change some things in your Test6.tex file:

In your tex file there should be the following lines:

point meta min=...,
point meta max=...,


With on the dots your values. This limits the colours of your colormap. These two lines needs to be removed. After doing this already a plot should be generated with the right color values but the colorbar definition will still wrong in order to fix this, the next code block

colormap={mymap}{[1pt] ...}


needs to be placed after

colormap={patchmap}{[1pt] ...}


This will fix the colorbar. But still the tickvalues of the colorbar will be off. This can be fixed manually by using:

colorbar style={
ytick={...},
yticklabels={...}
}


If it is not completely clear I can make the changes in your file.