utils.py 文件源码

def random_points_in_circle(n,xx,yy,rr):
  """
  get n random points in a circle.
  """

  rnd = random(size=(n,3))
  t = TWOPI*rnd[:,0]
  u = rnd[:,1:].sum(axis=1)
  r = zeros(n,'float')
  mask = u>1.
  xmask = logical_not(mask)
  r[mask] = 2.-u[mask]
  r[xmask] = u[xmask]
  xyp = reshape(rr*r,(n,1))*column_stack( (cos(t),sin(t)) )
  dartsxy  = xyp + array([xx,yy])
  return dartsxy