util.py 文件源码

def pseudo_inverse_stable(svd, eps=1e-7):
  """pseudo-inverse, accepting existing values"""
  # use float32 machine precision as cut-off (works for MKL)
  # https://www.wolframcloud.com/objects/927b2aa5-de9c-46f5-89fe-c4a58aa4c04b
  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"
  max_eigen = tf.reduce_max(s)
  si = tf.where(s/max_eigen<eps, 0.*s, tf.pow(s, -0.9))
  return u @ tf.diag(si) @ tf.transpose(v)

# todo: rename l to L