I need to center the axes in the coordinate origin. However, the axes is not centered and extends down as shown by the red circle.
Thank you for helping me :D
...
\pgfplotsset{compat=1.11}
...
\begin{document}
\begin{tikzpicture}[scale=1.5]
\begin{axis} [
xlabel = \textit{Voltage},
ylabel = \textit{Current},
axis lines = middle,
enlarge y limits = true,
xmin = 0, xmax = 90,
ymin = 0, ymax = 150,
width=15cm, height=8cm,
grid = major,
grid style = {dashed, line width=.1pt, draw=gray!30},
legend pos = north east,
]
\addplot table[x index = {0}, y index = {1}]{\mydata};
\legend{Townsend}
\end{axis}
\end{tikzpicture}
\end{document}
