\def\yaxIs{\ifnum\yscaling=1\raise\ynumbering%
\hbox to\xpos{\advance\ylength\ht2%
\vbox to\ylength{\xfinal0\yfinal0%
\divide\ymin\ybasis\divide\ymax\ybasis%
\divide\yinc\ybasis\xvalfrac360\chelptwo180%
\ifnum\ybasis=10\else\message{ywinkel-error!}\fi%
\loop\advance\xfinal1\xvalint\ymin%
\ifnum\xvalint>\chelptwo\negadvAnce\xvalint\xvalfrac\fi\relax%
\ifnum\xvalint>\chelptwo\negadvAnce\xvalint\xvalfrac\fi\relax%
\ifnum\xvalint>-\chelptwo\else\advance\xvalint\xvalfrac\fi\relax%
\ifnum\xvalint>-\chelptwo\else\advance\xvalint\xvalfrac\fi\relax%
\setbox\xfinal\hbox to\xpos{\hfill%
\ifnum\xvalint<0$-$\xvalint-\xvalint\fi\relax%
\number\xvalint$^\circ$\kern.5\em}%
\advance\ymin\yinc\ifnum\ymin>\ymax\yfinal1\fi\relax%
\ifnum\yfinal=0\repeat%
\loop\box\xfinal\negadvAnce\xfinal1\relax%
\ifnum\xfinal>0\vss\repeat}}\kern-\xpos\fi}%