def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def update(dt=0):
  global projpts, rgb, depth
  depth,_ = freenect.sync_get_depth()
  rgb,_ = freenect.sync_get_video()
  q = depth
  X,Y = np.meshgrid(range(640),range(480))
  # YOU CAN CHANGE THIS AND RERUN THE PROGRAM!
  # Point cloud downsampling
  d = 4
  projpts = calibkinect.depth2xyzuv(q[::d,::d],X[::d,::d],Y[::d,::d])
  refresh()