%
% tikztemplate.tex -- template for standalon tikz images
%
% (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}
\input{loggammadata.tex}
\begin{tikzpicture}[>=latex,thick,scale=\skala]

% add image content here

\def\dx{1}
\def\dy{0.6}
\def\xmax{8}
\def\xmin{-4.9}
\def\ymax{8}
\def\ymin{-3.1}

\fill[color=blue!20] ({\xmin*\dx},{\ymin*\dy}) rectangle ({-4*\dx},{\ymax*\dy});
\fill[color=blue!20] ({-3*\dx},{\ymin*\dy}) rectangle ({-2*\dx},{\ymax*\dy});
\fill[color=blue!20] ({-1*\dx},{\ymin*\dy}) rectangle ({-0*\dx},{\ymax*\dy});

\draw[->] ({\xmin*\dx-0.1},0) -- ({\xmax*\dx+0.3},0)
	coordinate[label={$x$}];
\draw[->] (0,{\ymin*\dy-0.1}) -- (0,{\ymax*\dy+0.3})
	coordinate[label={right:$y$}];

\begin{scope}
\clip ({\xmin*\dx},{\ymin*\dy}) rectangle ({\xmax*\dx},{\ymax*\dy});

\foreach \x in {-1,-2,-3,-4}{
	\draw[color=blue,line width=0.3pt]
		({\x*\dx},{\ymin*\dy}) -- ({\x*\dx},{\ymax*\dy});
}

\draw[color=red,line width=1pt] \loggammapath;

\loggammaplotzero
\loggammaplotone
\loggammaplottwo
\loggammaplotthree
\loggammaplotfour

\end{scope}

\foreach \y in {0.1,10,100,1000,1000}{
	\draw[line width=0.3pt]
		({\xmin*\dx},{ln(\y)*\dy}) 
		--
		({\xmax*\dx},{ln(\y)*\dy}) ;
}

\foreach \x in {1,...,8}{
	\draw ({\x*\dx},{-0.05}) -- ({\x*\dx},{0.05});
	\node at ({\x*\dx},0) [below] {$\x$};
}

\foreach \x in {-1,...,-4}{
	\draw ({\x*\dx},{-0.05}) -- ({\x*\dx},{0.05});
}
\foreach \x in {-1,...,-3}{
	\node at ({\x*\dx},0) [below right] {$\x$};
}
\node at ({-4*\dx},0) [below left] {$-4$};

\def\htick#1#2{
	\draw (-0.05,{ln(#1)*\dy}) -- (0.05,{ln(#1)*\dy});
	\node at (0,{ln(#1)*\dy}) [above right] {#2};
}

\htick{10}{$10^1$}
\htick{100}{$10^2$}
\htick{1000}{$10^3$}
\htick{0.1}{$10^{-1}$}

\node[color=red] at ({3*\dx},{ln(30)*\dy}) {$y=\log|\Gamma(x)|$};


\end{tikzpicture}
\end{document}