ref: 2e0a3ec2d5b2252ebab15e28998bac82c33e8edd
dir: /sys/src/cmd/plot/libplot/openpl.c/
#include "mplot.h"
void openpl(char *s){
	m_initialize(s);
	e0->left=mapminx;
	e0->bottom=mapmaxy;
	e0->sidex=mapmaxx-mapminx;
	e0->sidey=mapminy-mapmaxy;
	e0->scalex=e0->sidex;
	e0->scaley=e0->sidey;
	sscpy(e0, e1);
	move(0., 0.);
}