%
% rechteck.tex -- rechteck für Wertebereich der ell. Integrale
%
% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule
%
\documentclass[tikz]{standalone}
\usepackage{amsmath}
\usepackage{times}
\usepackage{txfonts}
\usepackage{pgfplots}
\usepackage{csvsimple}
\usetikzlibrary{arrows,intersections,math}
\begin{document}
\def\skala{1}
\begin{tikzpicture}[>=latex,thick,scale=\skala]

\def\dx{3}
\def\dy{3}

\input{rechteckpfade.tex}

\begin{scope}
	\clip ({-\xmax*\dx},{-\ymax*\dy}) rectangle ({\xmax*\dx},{\ymax*\dy});
	\fill[color=red!10] (0,{\ymax*\dy}) circle[radius=0.45];
	\fill[color=blue!10] (0,{-\ymax*\dy}) circle[radius=0.45];
	\draw[color=gray!80] (0,{\ymax*\dy}) -- (0,{\ymax*\dy-0.45});
	\draw[color=gray!80] (0,{-\ymax*\dy}) -- (0,{-\ymax*\dy+0.45});
\end{scope}

\draw ({-\xmax*\dx},{-\ymax*\dy}) rectangle ({\xmax*\dx},{\ymax*\dy});

\draw[->] ({-\xmax*\dx-0.3},0) -- ({\xmax*\dx+0.9},0)
	coordinate[label={$\operatorname{Re}F(k,z)$}];

\draw[<->,line width=0.7pt]
	({-\xmax*\dx},{\ymax*\dy+0.2})
	--
	({\xmax*\dx},{\ymax*\dy+0.2});
\draw[line width=0.2pt]
	({-\xmax*\dx},{\ymax*\dy})
	--
	({-\xmax*\dx},{\ymax*\dy+0.3});
\draw[line width=0.2pt]
	({\xmax*\dx},{\ymax*\dy})
	--
	({\xmax*\dx},{\ymax*\dy+0.3});

\node at ({-0.5*\xmax*\dx},{\ymax*\dy+0.2}) [above] {$2K(k)$};
\draw[->] (0,{\ymax*\dy}) -- (0,{\ymax*\dy+0.7})
	coordinate[label={right:$\operatorname{Im}F(k,z)$}];
\draw (0,{-\ymax*\dy}) -- (0,{-\ymax*\dy-0.2});

\draw[line width=0.2pt]
	({-\xmax*\dx-0.3},{-\ymax*\dy})
	--
	({-\xmax*\dx},{-\ymax*\dy});
\draw[line width=0.2pt]
	({-\xmax*\dx-0.3},{\ymax*\dy})
	--
	({-\xmax*\dx},{\ymax*\dy});
\draw[<->,line width=0.7pt] 
	({-\xmax*\dx-0.2},{\ymax*\dy})
	--
	({-\xmax*\dx-0.2},0);

\node at ({-\xmax*\dx-0.2},{-0.5*\ymax*\dy}) [rotate=90,above] {$K(k')$};
\node at ({-\xmax*\dx-0.2},{0.5*\ymax*\dy}) [rotate=90,above] {$K(k')$};

\draw[<->,line width=0.7pt] 
	({-\xmax*\dx-0.2},{-\ymax*\dy})
	--
	({-\xmax*\dx-0.2},0);

\node at ({\xmax*\dx},{\ymax*\dy}) [right] {$K(k)+iK(k')$};
\fill[color=white] ({\xmax*\dx},{\ymax*\dy}) circle[radius=0.05];
\draw ({\xmax*\dx},{\ymax*\dy}) circle[radius=0.05];

\end{tikzpicture}
\end{document}