Need some help getting started with TikZ, groupplots and color mapping of matrix

Question

I used Python to make the plot shown below (saved as png).

It should have a common colorbar and all data is read from a h5 file, but I thought saving it to a txt file or something using a Python script to read in for the TikZ figure.

There are 5 plots and 1 colorbar:

The first plots only has one variable (with values 0,25,33,50,66,75 %), each colored square represents the corresponding output, which can be represented by an array of length 6.

The four other plots have two variables (with values [0,25,33,50,66,75 %] and [0,1,2,3,4,5,6,7,8]) and can thus be represented by a 6x9 matrix.

I would like to make a TikZ figure just like the PNG, but off course with non-overlapping text and maybe a title for each subplot and a better outline of the colorbar (the png was quick and dirty to be able to quickly view the output).

Can anyone help me out here?

(If having the values is usefull, please tell me in what format it would be easiest and I'll upload a txt file asap.)

Edit: Adding the data in data.txt

data.txt

Edit2: I forgot to mention that I would like to be able to use \figureheight and \figurewidth, defined in the tex file, to adjust the dimensions (like I did in the figure from another question).

Answer 1

As I wasn't happy with what I could achieve with pgfplots, I tried writing something myself. Basically it's a foreach loop, which computes the color for a specific value and then draws a square. There were some obstacles, as I learned you need \xglobal to make color definitions global. The result is still far from automatic, but I'm thinking about adding a key-value interface via pgfkeys. Anyway, here's what I have so far:

Code

\documentclass[tikz,border=2mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.9}
\usepackage{xifthen}

\begin{document}

\newcommand{\mycolorbar}[6]% height,width,colors,label min,label max,label step
{   \foreach \x [count=\c] in {#3}{ \xdef\numcolo{\c}}
  \pgfmathsetmacro{\pieceheight}{#1/(\numcolo-1)}
  \xdef\lowcolo{}
  \foreach \x [count=\c] in {#3}
  { \ifthenelse{\c = 1}
    {}
    {   \fill[bottom color=\lowcolo,top color=\x] (0,{(\c-2)*\pieceheight}) rectangle (#2,{(\c-1)*\pieceheight});
    }
    \xdef\lowcolo{\x}
  }
  \draw[thick] (0,0) rectangle (#2,#1);
  \pgfmathsetmacro{\secondlabel}{#4+#6}
  \pgfmathsetmacro{\lastlabel}{#5+0.01}
  \pgfkeys{/pgf/number format/.cd,fixed,precision=2}
  \foreach \x in {#4,\secondlabel,...,\lastlabel}
  { \draw[thick] (#2,{(\x-#4)/(#5-#4)*#1}) -- ++ (0.15,0) node[right] {\pgfmathprintnumber{\x}};
  }
}

\newcommand{\mycolor}[4]% z, min, max, colors
{   \foreach \x [count=\c] in {#4}
    { \xdef\numcolors{\c}
    }
    \foreach \x [count=\c] in {#4}  
    {   \ifthenelse{\c > 1}
        {   \pgfmathsetmacro{\lowbound}{(\c-2)/(\numcolors-1)*(#3-#2)+#2}
            \pgfmathsetmacro{\upbound}{(\c-1)/(\numcolors-1)*(#3-#2)+#2}
            \pgfmathtruncatemacro{\thisinterval}{and(#1>=\lowbound,#1<\upbound)?1:0}
            \ifthenelse{\thisinterval = 1}
            {   \pgfmathtruncatemacro{\myperc}{(#1-\lowbound)/(\upbound-\lowbound)*100}
                \pgfmathtruncatemacro{\myinvperc}{100-\myperc}
                \xglobal\colorlet{myfillcolor}{rgb:\lowcolor,\myinvperc;\x,\myperc}
            }
            {}
            \pgfmathtruncatemacro{\isbigger}{#1>#3?1:0}
            \ifthenelse{\isbigger=1}
            {   \xglobal\colorlet{myfillcolor}{\x}
            }
            {}
        }
        {   \pgfmathtruncatemacro{\issmaller}{#1<#2?1:0}
            \ifthenelse{\issmaller=1}
            {   \xglobal\colorlet{myfillcolor}{\x}
            }
            {}
        }
        \xdef\lowcolor{\x}
    }
}

\begin{tikzpicture}[scale=0.4]
    \foreach \z [count=\cz] in {4.21, 4.21, 4.21, 4.21, 4.21, 4.38, 4.38, 4.38, 4.38, 14.74, 14.74, 14.74, 14.74, 14.74, 15.11, 15.11, 16.51, 18.54, 23.02, 23.02, 23.02, 23.02, 23.02, 22.84, 22.84, 24.77, 26.93, 25.18, 25.18, 25.18, 25.18, 25.18, 25.03, 25.03, 25.27, 28.47, 37.71, 37.71, 37.71, 37.71, 37.71, 37.71, 38.51, 40.13, 39.68, 33.62, 33.62, 33.62, 33.62, 33.62, 33.62, 34.02, 34.02, 31.52}
    {   \definecolor{myfillcolor}{rgb}{128,128,128}
        \mycolor{\z}{0}{45}{blue!50!black, blue!50!gray, blue!50!cyan, green!50!cyan, lime, yellow!50!orange, orange, red, red!50!black}
        \fill[myfillcolor] ({mod(\cz-1,9)},{div(\cz-1,9)}) rectangle ++(1,1) node[pos=0.5,black] {};
    }
    \draw[thick] (0,0) rectangle (9,6);
    \foreach \x in {0,...,8}
    { \draw[thick] (\x+0.5,6) -- (\x+0.5,5.7);
        \draw[thick] (\x+0.5,0.3) -- (\x+0.5,0) node[below] {\tiny\x};
    }
    \foreach \y [count=\c] in {0,25,33,50,66,75}
    { \draw[thick] (9,\c-0.5) -- (8.7,\c-0.5);
        \draw[thick] (0.3,\c-0.5) -- (0,\c-0.5) node[left] {\tiny\y};
    }
    \node[below] at (4.5,-0.5) {first raster};

\begin{scope}[shift={(11,0)}]
    \foreach \z [count=\cz] in {1,...,54}
    {   \definecolor{myfillcolor}{rgb}{128,128,128}
        \pgfmathsetmacro{\zr}{rnd*45}
        \mycolor{\zr}{0}{45}{blue!50!black, blue!50!gray, blue!50!cyan, green!50!cyan, lime, yellow!50!orange, orange, red, red!50!black}
        \fill[myfillcolor] ({mod(\cz-1,9)},{div(\cz-1,9)}) rectangle ++(1,1) node[pos=0.5,black] {};
    }
        \draw[thick] (0,0) rectangle (9,6);
    \foreach \x in {0,...,8}
    { \draw[thick] (\x+0.5,6) -- (\x+0.5,5.7);
        \draw[thick] (\x+0.5,0.3) -- (\x+0.5,0) node[below] {\tiny\x};
    }
    \foreach \y [count=\c] in {0,25,33,50,66,75}
    { \draw[thick] (9,\c-0.5) -- (8.7,\c-0.5);
        \draw[thick] (0.3,\c-0.5) -- (0,\c-0.5) node[left] {\tiny\y};
    }
    \node[below] at (4.5,-0.5) {chaos};
\end{scope}

\begin{scope}[shift={(0,-8)}]
    \foreach \z [count=\cz] in {1,...,54}
    {   \definecolor{myfillcolor}{rgb}{128,128,128}
        \pgfmathsetmacro{\zr}{(mod(\cz-1,9)+div(\cz-1,9))*3}
        \mycolor{\zr}{0}{45}{blue!50!black, blue!50!gray, blue!50!cyan, green!50!cyan, lime, yellow!50!orange, orange, red, red!50!black}
        \fill[myfillcolor] ({mod(\cz-1,9)},{div(\cz-1,9)}) rectangle ++(1,1) node[pos=0.5,black] {};
    }
        \draw[thick] (0,0) rectangle (9,6);
    \foreach \x in {0,...,8}
    { \draw[thick] (\x+0.5,6) -- (\x+0.5,5.7);
        \draw[thick] (\x+0.5,0.3) -- (\x+0.5,0) node[below] {\tiny\x};
    }
    \foreach \y [count=\c] in {0,25,33,50,66,75}
    { \draw[thick] (9,\c-0.5) -- (8.7,\c-0.5);
        \draw[thick] (0.3,\c-0.5) -- (0,\c-0.5) node[left] {\tiny\y};
    }
    \node[below] at (4.5,-0.5) {gradient};
\end{scope}

\begin{scope}[shift={(11,-8)}]
    \foreach \z [count=\cz] in {1,...,54}
    {   \definecolor{myfillcolor}{rgb}{128,128,128}
        \pgfmathsetmacro{\zr}{pow(mod(\cz-1,9),2)+pow(div(\cz-1,9),2)-11}
        \mycolor{\zr}{0}{45}{blue!50!black, blue!50!gray, blue!50!cyan, green!50!cyan, lime, yellow!50!orange, orange, red, red!50!black}
        \fill[myfillcolor] ({mod(\cz-1,9)},{div(\cz-1,9)}) rectangle ++(1,1) node[pos=0.5,black] {};
    }
    \draw[thick] (0,0) rectangle (9,6);
    \foreach \x in {0,...,8}
    { \draw[thick] (\x+0.5,6) -- (\x+0.5,5.7);
        \draw[thick] (\x+0.5,0.3) -- (\x+0.5,0) node[below] {\tiny\x};
    }
    \foreach \y [count=\c] in {0,25,33,50,66,75}
    { \draw[thick] (9,\c-0.5) -- (8.7,\c-0.5);
        \draw[thick] (0.3,\c-0.5) -- (0,\c-0.5) node[left] {\tiny\y};
    }
    \node[below] at (4.5,-0.5) {floor \& roof};
\end{scope}

\begin{scope}[shift={(21,-8)}]
    \mycolorbar{14}{1}{blue!50!black, blue!50!gray, blue!50!cyan, green!50!cyan, lime, yellow!50!orange, orange, red, red!50!black}{0}{45}{5}
\end{scope}
\end{tikzpicture}

\end{document}

Output