Add image to documentation.

partitioned-heat-conduction-schwarz/README.md

@@ -9,6 +9,12 @@ summary: We solve a simple heat equation. The domain is partitioned and the coup
 Get the [case files of this tutorial](https://github.com/precice/tutorials/tree/master/partitioned-heat-conduction-schwarz). Read how in the [tutorials introduction](https://www.precice.org/tutorials.html).
 {% endnote %}
 
+## Setup
+
+We solve a partitioned heat equation, but apply an overlapping Schwarz-type domain decomposition method in this tutorial.
+
+![Case setup of partitioned-heat-conduction case with Schwarz-type domain decomposition](images/tutorials-partitioned-heat-conduction-schwarz-setup.png)
+
 ## Running the simulation
 
 This tutorial is for FEniCS.

partitioned-heat-conduction-schwarz/images/.gitignore

@@ -0,0 +1,9 @@
+*.aux
+*.auxlock
+*.fdb_latexmk
+*.fls
+*.log
+tikzcode.pdf
+*.synctex.gz
+*.dpth
+*.md5

partitioned-heat-conduction-schwarz/images/tikzcode.tex

@@ -0,0 +1,75 @@
+\documentclass{standalone}
+
+\usepackage{tikz}
+\usetikzlibrary{fit,positioning,calc}
+
+\usepackage{pgfplots}
+\pgfplotsset{
+    compat=1.16,
+}
+\usepgfplotslibrary{external}
+\tikzexternalize[
+    only named,
+]
+
+\definecolor{pblue}{RGB}{0,102,189}  % precice blue
+\definecolor{porange}{RGB}{243,98,33}  % precice orange
+
+% Make the 'export as png' a seperate style, with default density 200
+\tikzset{
+    export as png/.style={
+        external/system call/.add={}{
+            && convert -density #1 -transparent white "\image.pdf" "\image.png"
+        },
+    },
+    export as png/.default={200},
+}
+
+\begin{document}
+
+\tikzset{export as png}
+\tikzsetnextfilename{tutorials-partitioned-heat-conduction-schwarz-setup}
+\begin{tikzpicture}
+    \draw[fill=pblue!50](0,0) rectangle ++(1,1);
+    \draw
+    (0,0) coordinate (a)
+    rectangle
+        ++(3,3) coordinate (b);
+        \node[fill=pblue!50, draw=black, fit=(a) (b),inner sep=0pt] (participantL) {$\Omega_\mathcal{L}$};
+
+        \draw
+        ($(participantL.south east)+(1,0)$) coordinate (a)
+        rectangle
+        ++(3,3) coordinate (b);
+        \node[fill=porange!50, draw=black, fit=(a) (b),inner sep=0pt] (participantR) {$\Omega_\mathcal{R}$};
+
+        \draw
+        ($(participantL.south east)-(1,0)$) coordinate (a)
+        rectangle
+        ($(participantL.north east)$) coordinate (b);
+        \node[fill=porange!50,opacity=0.5, fit=(a) (b),inner sep=0pt] (overlapL){};
+
+        \draw
+        ($(participantR.south west)+(1,0)$) coordinate (a)
+        rectangle
+        ($(participantR.north west)$) coordinate (b);
+        \node[fill=pblue!50,opacity=0.5, fit=(a) (b),inner sep=0pt] (overlapR){};
+
+        \node[below = 0.2cm of participantR](overlapLabel){Overlapping region: $\Omega_\mathcal{R}\cap\Omega_\mathcal{L}$};
+        \draw[dashed] ([yshift=-.5cm]overlapL.center) -- (overlapLabel);
+        \draw[dashed] ([yshift=-.5cm]overlapR.center) -- (overlapLabel);
+
+        \draw[very thick, pblue]($(participantL.south east)-(1,0)$) -- ($(participantL.north east)-(1,0)$);
+        \draw[very thick, porange]($(participantR.south west)+(1,0)$) -- ($(participantR.north west)+(1,0)$);
+
+        \draw[very thick, porange](participantL.south east) -- node[left]{$\Gamma_\mathcal{R}$}($(participantL.north east)$);
+        \draw[very thick, pblue](participantR.south west) -- node[right]{$\Gamma_\mathcal{L}$} ($(participantR.north west)$);
+
+    \node[left = 0cm of participantL,align=center] {Dirichlet solver $\mathcal{L}$\\ acts on left part $\Omega_\mathcal{L}$};
+    \node[right = 0cm of participantR,align=center] {Dirichlet solver $\mathcal{R}$\\ acts on right part $\Omega_\mathcal{R}$};
+
+    \draw[->]($(participantR.north west)+(1,0)$) to[out=150,in=30] node[above right,align=center]{Temperature $u$ on $\Gamma_\mathcal{R}$ for $\mathcal{L}$} (participantL.north east);
+    \draw[->]($(participantL.north east)-(1,0)$) to[out=30,in=150] node[above left,align=center]{Temperature $u$ on $\Gamma_\mathcal{L}$ for $\mathcal{R}$} (participantR.north west);
+\end{tikzpicture}
+
+\end{document}