def setworldcoordinates(self, llx, lly, urx, ury):
        if self.mode() != "world":
            self.mode("world")
        xspan = float(urx - llx)
        yspan = float(ury - lly)
        wx, wy = self._window_size()
        self.screensize(wx-20, wy-20)
        oldxscale, oldyscale = self.xscale, self.yscale
        self.xscale = self.canvwidth / xspan
        self.yscale = self.canvheight / yspan
        srx1 = llx * self.xscale
        sry1 = -ury * self.yscale
        srx2 = self.canvwidth + srx1
        sry2 = self.canvheight + sry1
        self._setscrollregion(srx1, sry1, srx2, sry2)
        self._rescale(self.xscale/oldxscale, self.yscale/oldyscale)
        #self.update()
Set up a user defined coordinate-system.
dataset/ETHPy150Open amrdraz/kodr/app/brython/www/src/Lib/site-packages/turtle.py/TurtleScreen.setworldcoordinates