from pyx import * c = canvas.canvas() p1 = path.curve(0, 0, 1, 0, 1, 1, 2, 1) p2 = path.line(0, 0, p1.arclen(), 0) c.stroke(p1) c.stroke(p2) c.writeEPSfile("arclen") c.writePDFfile("arclen")