[Tex/LaTex] PGFPlots: How to reproduce MATLAB colorbar and make it span multiple plots

pgfplotstikz-pgf

Considering my previous question, I have some MATLAB contour plots whose original colormap parula is defined by the following rgb data:

MATLAB colormap (parula)

http://pastebin.com/akFwwK6x

How can I reproduce the original MATLAB color bar shown below using PGFPlots and make it span horizontally over the space under the three subfigures (knowing that the minimum value of colorbar is 300 and maximum is 1600)?

\RequirePackage{luatex85}
\documentclass{article}
\usepackage{pgfplots,caption,subcaption,showframe,siunitx}
\usepgfplotslibrary{groupplots}
\pgfplotsset{compat=newest}


\begin{document}
    \begin{figure}
        \centering
        \begin{tikzpicture}
        \begin{groupplot}[
        group style={
            group name=G,
            group size=3 by 1,
            y descriptions at=edge left,
            horizontal sep=20pt % adjust as needed
        },
        enlargelimits=false,
        width=0.28\textwidth-width("300"),
        height=0.25\textheight,
        scale only axis, axis on top , grid=both,
        ]

        \nextgroupplot
        \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-a};
        \nextgroupplot
        \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-b};
        \nextgroupplot
        \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-c};
        \end{groupplot}

        \end{tikzpicture}

    \end{figure}

\end{document}

Best Answer

So you mean something like the following?
(Because I think you will modify the shown colorbar so that it corresponds to the one from your previous questions, maybe also the hints in https://tex.stackexchange.com/a/336647/95441 are helpful.)

% used PGFPlots v1.14
\RequirePackage{luatex85}
\documentclass{article}
\usepackage{pgfplots}
    \usepgfplotslibrary{groupplots}
    \pgfplotsset{
        % define the colormap
        colormap={parula}{
            rgb=(0.208100000000000,0.166300000000000,0.529200000000000)
            rgb=(0.211623809523810,0.189780952380952,0.577676190476191)
            rgb=(0.212252380952381,0.213771428571429,0.626971428571429)
            rgb=(0.208100000000000,0.238600000000000,0.677085714285714)
            rgb=(0.195904761904762,0.264457142857143,0.727900000000000)
            rgb=(0.170728571428571,0.291938095238095,0.779247619047619)
            rgb=(0.125271428571429,0.324242857142857,0.830271428571429)
            rgb=(0.0591333333333334,0.359833333333333,0.868333333333333)
            rgb=(0.0116952380952381,0.387509523809524,0.881957142857143)
            rgb=(0.00595714285714286,0.408614285714286,0.882842857142857)
            rgb=(0.0165142857142857,0.426600000000000,0.878633333333333)
            rgb=(0.0328523809523810,0.443042857142857,0.871957142857143)
            rgb=(0.0498142857142857,0.458571428571429,0.864057142857143)
            rgb=(0.0629333333333333,0.473690476190476,0.855438095238095)
            rgb=(0.0722666666666667,0.488666666666667,0.846700000000000)
            rgb=(0.0779428571428572,0.503985714285714,0.838371428571429)
            rgb=(0.0793476190476190,0.520023809523810,0.831180952380952)
            rgb=(0.0749428571428571,0.537542857142857,0.826271428571429)
            rgb=(0.0640571428571428,0.556985714285714,0.823957142857143)
            rgb=(0.0487714285714286,0.577223809523810,0.822828571428572)
            rgb=(0.0343428571428572,0.596580952380952,0.819852380952381)
            rgb=(0.0265000000000000,0.613700000000000,0.813500000000000)
            rgb=(0.0238904761904762,0.628661904761905,0.803761904761905)
            rgb=(0.0230904761904762,0.641785714285714,0.791266666666667)
            rgb=(0.0227714285714286,0.653485714285714,0.776757142857143)
            rgb=(0.0266619047619048,0.664195238095238,0.760719047619048)
            rgb=(0.0383714285714286,0.674271428571429,0.743552380952381)
            rgb=(0.0589714285714286,0.683757142857143,0.725385714285714)
            rgb=(0.0843000000000000,0.692833333333333,0.706166666666667)
            rgb=(0.113295238095238,0.701500000000000,0.685857142857143)
            rgb=(0.145271428571429,0.709757142857143,0.664628571428572)
            rgb=(0.180133333333333,0.717657142857143,0.642433333333333)
            rgb=(0.217828571428571,0.725042857142857,0.619261904761905)
            rgb=(0.258642857142857,0.731714285714286,0.595428571428571)
            rgb=(0.302171428571429,0.737604761904762,0.571185714285714)
            rgb=(0.348166666666667,0.742433333333333,0.547266666666667)
            rgb=(0.395257142857143,0.745900000000000,0.524442857142857)
            rgb=(0.442009523809524,0.748080952380952,0.503314285714286)
            rgb=(0.487123809523809,0.749061904761905,0.483976190476191)
            rgb=(0.530028571428571,0.749114285714286,0.466114285714286)
            rgb=(0.570857142857143,0.748519047619048,0.449390476190476)
            rgb=(0.609852380952381,0.747314285714286,0.433685714285714)
            rgb=(0.647300000000000,0.745600000000000,0.418800000000000)
            rgb=(0.683419047619048,0.743476190476191,0.404433333333333)
            rgb=(0.718409523809524,0.741133333333333,0.390476190476190)
            rgb=(0.752485714285714,0.738400000000000,0.376814285714286)
            rgb=(0.785842857142857,0.735566666666667,0.363271428571429)
            rgb=(0.818504761904762,0.732733333333333,0.349790476190476)
            rgb=(0.850657142857143,0.729900000000000,0.336028571428571)
            rgb=(0.882433333333333,0.727433333333333,0.321700000000000)
            rgb=(0.913933333333333,0.725785714285714,0.306276190476191)
            rgb=(0.944957142857143,0.726114285714286,0.288642857142857)
            rgb=(0.973895238095238,0.731395238095238,0.266647619047619)
            rgb=(0.993771428571429,0.745457142857143,0.240347619047619)
            rgb=(0.999042857142857,0.765314285714286,0.216414285714286)
            rgb=(0.995533333333333,0.786057142857143,0.196652380952381)
            rgb=(0.988000000000000,0.806600000000000,0.179366666666667)
            rgb=(0.978857142857143,0.827142857142857,0.163314285714286)
            rgb=(0.969700000000000,0.848138095238095,0.147452380952381)
            rgb=(0.962585714285714,0.870514285714286,0.130900000000000)
            rgb=(0.958871428571429,0.894900000000000,0.113242857142857)
            rgb=(0.959823809523810,0.921833333333333,0.0948380952380953)
            rgb=(0.966100000000000,0.951442857142857,0.0755333333333333)
            rgb=(0.976300000000000,0.983100000000000,0.0538000000000000)
        },
    }
\begin{document}
    \begin{tikzpicture}
        \begin{groupplot}[
            group style={
                group name=G,
                group size=3 by 1,
                y descriptions at=edge left,
                horizontal sep=20pt % adjust as needed
            },
            enlargelimits=false,
            % !!! I don't know what the part `width("300")' is doing exactly !!!
            width=0.28\textwidth-width("300"),
            height=0.25\textheight,
            scale only axis,
            axis on top,
            grid=both,
        ]
        % add the colorbar to the first groupplot
        \nextgroupplot [
            % it should be horizontal ...
            colorbar horizontal,
            % ... and sampled
            colorbar sampled,
            % define the style of the colorbar
            colorbar style={
                % it should be positioned at ...
                at=(G c1r1.below south west),
                % ... with the anchor ...
                anchor=north west,
                % ... with the same width as the axis parts of the groupplots,
                % i.e. 3 times the width of a single groupplot plus two times
                % the width of the horizontal sep of the groupplots, ...
                parent axis width=3*(0.28\textwidth-width("300")) + 2*20pt,
                % ... and the start and end points ...
                point meta min=300,
                point meta max=1600,
                % ... and the number of samples should be identical to the
                % number of colors in the colormap
                samples={
                    \pgfplotscolormapsizeof{%
                        \pgfkeysvalueof{/pgfplots/colormap name}%
                    }+1
                },
            },
        ]
            \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-a};
        \nextgroupplot
            \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-b};
        \nextgroupplot
            \addplot graphics [xmin=0, xmax=50, ymin=0, ymax=150] {example-image-c};
        \end{groupplot}

%        % for debugging purposes only
%        \draw [red,very thin]
%            (G c1r1.south west) -- +(0,-1cm)
%            (G c3r1.south east) -- +(0,-1cm)
%        ;

    \end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] pgfplots multiple plots in one file

You can use gnuplot in the background by using \addplot gnuplot [raw gnuplot] {<gnuplot commands>};:

\documentclass{article}
\usepackage{pgfplots}
\usepackage{filecontents}

\begin{filecontents*}{data.txt}
1 1
2 4
3 9
4 16
5 25


1 1
2.5 5
6 12
\end{filecontents*}


\begin{document}
\begin{tikzpicture}
\begin{axis}
\addplot gnuplot [raw gnuplot] {plot 'data.txt' index 0};
\addplot gnuplot [raw gnuplot] {plot 'data.txt' index 1};
\end{axis}
\end{tikzpicture}
\end{document}

[Tex/LaTex] Color coded plots with colorbar in pgfplots

I took a parula scale written by Jake and defined the colormap to use it. The curves are plotted with a for-each loop. I set the meta data of the points to the slope variable. The option mesh plots the lines with the colour of its meta data.

% arara: pdflatex

\documentclass{article}
\usepackage{pgfplots}

\pgfplotsset{%
    ,compat=1.11
    ,colormap={parula}{%
        rgb=(0.2081,0.1663,0.5292)rgb=(0.2116,0.1898,0.5777)rgb=(0.2123,0.2138,0.627)
        rgb=(0.2081,0.2386,0.6771)rgb=(0.1959,0.2645,0.7279)rgb=(0.1707,0.2919,0.7792)
        rgb=(0.1253,0.3242,0.8303)rgb=(0.0591,0.3598,0.8683)rgb=(0.0117,0.3875,0.882)
        rgb=(0.006,0.4086,0.8828) rgb=(0.0165,0.4266,0.8786)rgb=(0.0329,0.443,0.872)
        rgb=(0.0498,0.4586,0.8641)rgb=(0.0629,0.4737,0.8554)rgb=(0.0723,0.4887,0.8467)
        rgb=(0.0779,0.504,0.8384) rgb=(0.0793,0.52,0.8312)  rgb=(0.0749,0.5375,0.8263)
        rgb=(0.0641,0.557,0.824)  rgb=(0.0488,0.5772,0.8228)rgb=(0.0343,0.5966,0.8199)
        rgb=(0.0265,0.6137,0.8135)rgb=(0.0239,0.6287,0.8038)rgb=(0.0231,0.6418,0.7913)
        rgb=(0.0228,0.6535,0.7768)rgb=(0.0267,0.6642,0.7607)rgb=(0.0384,0.6743,0.7436)
        rgb=(0.059,0.6838,0.7254) rgb=(0.0843,0.6928,0.7062)rgb=(0.1133,0.7015,0.6859)
        rgb=(0.1453,0.7098,0.6646)rgb=(0.1801,0.7177,0.6424)rgb=(0.2178,0.725,0.6193)
        rgb=(0.2586,0.7317,0.5954)rgb=(0.3022,0.7376,0.5712)rgb=(0.3482,0.7424,0.5473)
        rgb=(0.3953,0.7459,0.5244)rgb=(0.442,0.7481,0.5033) rgb=(0.4871,0.7491,0.484)
        rgb=(0.53,0.7491,0.4661)  rgb=(0.5709,0.7485,0.4494)rgb=(0.6099,0.7473,0.4337)
        rgb=(0.6473,0.7456,0.4188)rgb=(0.6834,0.7435,0.4044)rgb=(0.7184,0.7411,0.3905)
        rgb=(0.7525,0.7384,0.3768)rgb=(0.7858,0.7356,0.3633)rgb=(0.8185,0.7327,0.3498)
        rgb=(0.8507,0.7299,0.336) rgb=(0.8824,0.7274,0.3217)rgb=(0.9139,0.7258,0.3063)
        rgb=(0.945,0.7261,0.2886) rgb=(0.9739,0.7314,0.2666)rgb=(0.9938,0.7455,0.2403)
        rgb=(0.999,0.7653,0.2164) rgb=(0.9955,0.7861,0.1967)rgb=(0.988,0.8066,0.1794)
        rgb=(0.9789,0.8271,0.1633)rgb=(0.9697,0.8481,0.1475)rgb=(0.9626,0.8705,0.1309)
        rgb=(0.9589,0.8949,0.1132)rgb=(0.9598,0.9218,0.0948)rgb=(0.9661,0.9514,0.0755)
        rgb=(0.9763,0.9831,0.0538)
        }
    }

\begin{document}
\begin{tikzpicture}
    \begin{axis}[%
        ,ymin=0,xmin=0,ymax=5,xmax=1
        ,colorbar
        ,colorbar style={ylabel=line slope}
        ]
        \foreach \m in {1,1.2,...,5} % you will need {1,...,5} here, but it looked so beautiful...
        {\edef\temp{\noexpand\addplot[mesh,point meta=\m] {x*\m};}\temp}
    \end{axis}
\end{tikzpicture}
\end{document}

enter image description here

As asked in your comment, here is a solution loading data from files:

% arara: pdflatex

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.11}
\usepackage{filecontents}
\begin{filecontents}{data_1.dat}
    0 0
    1 1
\end{filecontents}
\begin{filecontents}{data_2.dat}
    0 0
    1 2
\end{filecontents}
\begin{filecontents}{data_3.dat}
    0 0
    1 3
\end{filecontents}

\begin{document}
    \begin{tikzpicture}
    \begin{axis}[%
    ,ymin=0,xmin=0,ymax=5,xmax=1
    ,colorbar
    ,colorbar style={ylabel=line slope}
    ]
    \foreach \m in {1,...,3}
    {\edef\temp{\noexpand\addplot[mesh,point meta=\m] table {data_\m.dat};}\temp}
    \end{axis}
    \end{tikzpicture}
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] pgfplots multiple plots in one file

[Tex/LaTex] Color coded plots with colorbar in pgfplots

Related Question