% This file is embedded in datatool-user.pdf version 3.1 2025-03-10
% Example 178 Redefining the Start and End Hooks
% Label: "ex:plotxyhooks"
% arara: pdflatex
% arara: pdfcrop
\documentclass[12pt]{article}
\pagestyle{empty}
\begin{filecontents}[noheader,overwrite]{xydata.csv}
X,Y
-3.5,-2.75
-3,3
-2.5,-1
-1,1.5
1,-4.2
2.6,1.8
3.2,-0.4
\end{filecontents}

\usepackage{dataplot}
\DTLsetup{store-datum}
\DTLread[name=xydata]{xydata} 

\renewcommand{\DTLplotdisplayticklabel}[1]{\ensuremath{#1}}
\renewcommand{\DTLplotatbegintikz}{\draw (0,0) node[anchor=north east] {0};}
\renewcommand{\DTLplotatendtikz}{
 \draw[blue,dotted] (\DTLminX,\DTLminY) -- (\DTLmaxX, \DTLminY)
 node[right] {$y_{\min} = \DTLminY$};
 \draw[blue,dotted] (\DTLminX,\DTLmaxY) -- (\DTLmaxX, \DTLmaxY)
 node[right] {$y_{\max} = \DTLmaxY$};
 } 
\begin{document}
\DTLplot{xydata}{
 x=X, y={Y},
 tick-dir=out, tick-gap=1, round=0,
 extend-axes={0,0.5}, 
 tick-label-style={font=\small},
 tick-label-offset=0pt,
 axis-style={->,thick},
 max-x-label={$x$}, max-y-label={$y$},
 style=lines, width=3in, height=3in
} 
\end{document}