%!TEX pdflatex

\documentclass[a4paper,12pt,french]{article}
\usepackage[margin=1.5cm]{geometry}
\usepackage{ProfLycee}
\usepackage{babel}

\NewDocumentCommand\DrawOpenRightHook{ m m }{
	\draw[red,thick] ({#1 + 0.1}, {#2 + 0.025}) -- (#1,#2 + 0.025) -- (#1,#2 - 0.025) -- ({#1 + 0.1}, {#2 - 0.025});
}

\defKV[fctrepart]{%
	Couleur=\def\FctRepartColor{#1},%
	Epaisseur=\def\FctRepartThickness{#1},%
}

\setKVdefault[fctrepart]{%
	Couleur=red,%
	Epaisseur=semithick
}

\NewDocumentCommand\FonctionRepartTikz{ O{} m }{%
	\restoreKV[fctrepart]%
	\setKV[fctrepart]{#1}%
	\setsepchar[.]{/.,}%
	\readlist*\ListeFonctRepart{#2}%
	\def\NbPortions{\ListeFonctRepartlen}
	\foreach \i in {1,2,...,\ListeFonctRepartlen}
	{%
		\IfStrEq{\ListeFonctRepart[\i,2]}{*}%
		{\def\valxdeb{\xmin}}%
		{%
			\itemtomacro\ListeFonctRepart[\i,2]\valxdeb%
			\DrawOpenRightHook{\ListeFonctRepart[\i,2]}{\ListeFonctRepart[\i,1]}%
		}%
		\IfStrEq{\ListeFonctRepart[\i,3]}{*}%
		{\def\valxfin{\xmax}}%
		{%
			\itemtomacro\ListeFonctRepart[\i,3]\valxfin%
			\DrawOpenRightHook{\ListeFonctRepart[\i,3]}{\ListeFonctRepart[\i,1]}%
		}%
		\draw[very thick,red] ({\valxdeb},{\ListeFonctRepart[\i,1]})--({\valxfin},{\ListeFonctRepart[\i,1]}) ;
	}%
}

\begin{document}

\begin{PresentationCode}{}
\begin{tikzpicture}[y=4cm,xmin=-2,xmax=10,ymin=-0.1,ymax=1.1]
	\AxesTikz \AxexTikz{0,2,4,6,8}
	\foreach \y in {1/3,1/2,2/3,1}
	{\draw[thick] (2pt,{\y})--++(-4pt,0) node[left] {\ConversionFraction{\y}} ;}
	\FonctionRepartTikz{0,*,0 / {1/3},0,2 / {1/2},2,4 / {2/3},4,6 / 1,6,*}
\end{tikzpicture}
\end{PresentationCode}

\end{document}