#!/usr/bin/env python from pylab import * theta = arange(0,8*pi,0.1) a=1 b=.2 for dt in arange(0,2*pi,pi/2.0): x = a*cos( theta+dt )*exp(b*theta) y = a*sin( theta+dt )*exp(b*theta) dt = dt+pi/4.0 x2 = a*cos( theta+dt )*exp(b*theta) y2 = a*sin( theta+dt )*exp(b*theta) xf = concatenate( (x,x2[::-1]) ) yf = concatenate( (y,y2[::-1]) ) p1=fill(xf,yf) show()