def smbezier(self, x2, y2, x, y):
        self.path.append(
            'S' + str(x2) + ',' + str(y2) + ' ' + str(x) + ',' + str(y))
smooth bezier with xy2 to xy absolut
dataset/ETHPy150Open CGATOxford/cgat/CGAT/SVGdraw.py/pathdata.smbezier