whitening_util.py 文件源码

def pseudo_inverse_sqrt2(svd, eps=1e-7):
  """half pseduo-inverse, accepting existing values"""
  # zero threshold for eigenvalues
  if svd.__class__.__name__=='SvdTuple':
    (s, u, v) = (svd.s, svd.u, svd.v)
  elif svd.__class__.__name__=='SvdWrapper':
    (s, u, v) = (svd.s, svd.u, svd.v)
  else:
    assert False, "Unknown type"
  si = tf.where(tf.less(s, eps), s, 1./tf.sqrt(s))
  return u @ tf.diag(si) @ tf.transpose(v)