Python math_ops.complex函数代码示例

  def testStripDefaultAttrsInconsistentConsumerDefaults(self):
    if ops._USE_C_API: return  # TODO(skyewm): get this working

    export_dir = self._get_export_dir(
        "test_strip_default_attrs_no_consumer_defaults")
    builder = saved_model_builder.SavedModelBuilder(export_dir)

    # Add a graph with two float32 variables and a Complex Op composing them
    # with strip_default_attrs enabled. This must remove the following
    # defaults for the "Complex" Op:
    #   o "T"    : float32.   (input type)
    #   o "Tout" : complex64. (output type)
    with session.Session(graph=ops.Graph()) as sess:
      real_num = variables.Variable(1.0, dtype=dtypes.float32, name="real")
      imag_num = variables.Variable(2.0, dtype=dtypes.float32, name="imag")
      math_ops.complex(real_num, imag_num, name="complex")
      sess.run(variables.global_variables_initializer())
      builder.add_meta_graph_and_variables(
          sess, ["foo"], strip_default_attrs=True)

    # Save the SavedModel to disk in text format.
    builder.save(as_text=True)

    # Update the Op registry to remove defaults for all attrs("T", "Tout") from
    # the "Complex" OpDef.
    complex_op_def = op_def_registry.get_registered_ops()["Complex"]
    original_complex_op_def = op_def_pb2.OpDef()
    original_complex_op_def.CopyFrom(complex_op_def)
    for attr_def in complex_op_def.attr:
      attr_def.ClearField("default_value")

    # Loading the SavedModel via the loader must fail because the SavedModel
    # does not have any attr values for the "Complex" node and the current
    # op registry does not have have any default values for the "Complex" op.
    sess = session.Session(graph=ops.Graph())
    with self.assertRaisesRegexp(
        ValueError,
        "Expected one attr with name .*T(out)?.* in name: \"complex\".*"):
      loader.load(sess, ["foo"], export_dir)

    # Update the Op registry to change the defaults for attr "Tout"
    # (complex64 -> complex128).
    complex_op_def.CopyFrom(original_complex_op_def)
    for attr_def in complex_op_def.attr:
      if attr_def.name == "Tout":
        attr_def.default_value.type = types_pb2.DT_COMPLEX128

    # Loading the SavedModel via the loader must set "Tout" attr_value for the
    # "Complex" node according to the latest defaults (complex128). This is
    # expected to fail the model import as there is no OpKernel registered to
    # handle attrs "T" (float32) and "Tout" (complex128).
    sess = session.Session(graph=ops.Graph())
    with self.assertRaisesRegexp(
        errors.InvalidArgumentError,
        ".*No OpKernel was registered to support Op \'Complex\' with these "
        "attrs..*"):
      loader.load(sess, ["foo"], export_dir)

def _AngleGrad(op, grad):
  """Returns -grad / (Im(x) + iRe(x))"""
  x = op.inputs[0]
  with ops.control_dependencies([grad]):
    re = math_ops.real(x)
    im = math_ops.imag(x)
    z = math_ops.reciprocal(math_ops.complex(im, re))
    zero = constant_op.constant(0, dtype=grad.dtype)
    complex_grad = math_ops.complex(grad, zero)
    return -complex_grad * z

  def testDefaultAttrStripping(self):
    """Verifies that default attributes are stripped from a graph def."""

    # Complex Op has 2 attributes with defaults:
    #   o "T"    : float32.
    #   o "Tout" : complex64.

    # When inputs to the Complex Op are float32 instances, "T" maps to float32
    # and "Tout" maps to complex64. Since these attr values map to their
    # defaults, they must be stripped unless stripping of default attrs is
    # disabled.
    with self.cached_session():
      real_num = constant_op.constant(1.0, dtype=dtypes.float32, name="real")
      imag_num = constant_op.constant(2.0, dtype=dtypes.float32, name="imag")
      math_ops.complex(real_num, imag_num, name="complex")

      # strip_default_attrs is enabled.
      meta_graph_def, _ = meta_graph.export_scoped_meta_graph(
          graph_def=ops.get_default_graph().as_graph_def(),
          strip_default_attrs=True)
      node_def = test_util.get_node_def_from_graph("complex",
                                                   meta_graph_def.graph_def)
      self.assertNotIn("T", node_def.attr)
      self.assertNotIn("Tout", node_def.attr)
      self.assertTrue(meta_graph_def.meta_info_def.stripped_default_attrs)

      # strip_default_attrs is disabled.
      meta_graph_def, _ = meta_graph.export_scoped_meta_graph(
          graph_def=ops.get_default_graph().as_graph_def(),
          strip_default_attrs=False)
      node_def = test_util.get_node_def_from_graph("complex",
                                                   meta_graph_def.graph_def)
      self.assertIn("T", node_def.attr)
      self.assertIn("Tout", node_def.attr)
      self.assertFalse(meta_graph_def.meta_info_def.stripped_default_attrs)

    # When inputs to the Complex Op are float64 instances, "T" maps to float64
    # and "Tout" maps to complex128. Since these attr values don't map to their
    # defaults, they must not be stripped.
    with self.session(graph=ops.Graph()):
      real_num = constant_op.constant(1.0, dtype=dtypes.float64, name="real")
      imag_num = constant_op.constant(2.0, dtype=dtypes.float64, name="imag")
      math_ops.complex(real_num, imag_num, name="complex")
      meta_graph_def, _ = meta_graph.export_scoped_meta_graph(
          graph_def=ops.get_default_graph().as_graph_def(),
          strip_default_attrs=True)
      node_def = test_util.get_node_def_from_graph("complex",
                                                   meta_graph_def.graph_def)
      self.assertEqual(node_def.attr["T"].type, dtypes.float64)
      self.assertEqual(node_def.attr["Tout"].type, dtypes.complex128)
      self.assertTrue(meta_graph_def.meta_info_def.stripped_default_attrs)

 def test_assert_non_singular_does_not_raise_for_complex_nonsingular(self):
   with self.test_session():
     x = [1., 0.]
     y = [0., 1.]
     diag = math_ops.complex(x, y)
     # Should not raise.
     linalg.LinearOperatorDiag(diag).assert_non_singular().run()

 def test_assert_positive_definite_does_not_raise_if_pd_and_complex(self):
   with self.test_session():
     x = [1., 2.]
     y = [1., 0.]
     diag = math_ops.complex(x, y)  # Re[diag] > 0.
     # Should not fail
     linalg.LinearOperatorDiag(diag).assert_positive_definite().run()

  def _test_unary_cwise_ops(self, ops, is_complex):
    for op in ops:
      with backprop.GradientTape(persistent=True) as g:
        x = random_ops.random_uniform([3, 5])
        g.watch(x)
        if is_complex:
          y = random_ops.random_uniform([3, 5])
          g.watch(y)
          x = math_ops.complex(x, y)

      # pylint: disable=cell-var-from-loop
      output_dtypes = []

      def loop_fn(i):
        with g:
          x1 = array_ops.gather(x, i)
          y1 = op(x1)
          outputs = [op(x), y1]
          if y1.dtype == dtypes.float32:
            loss = math_ops.reduce_sum(y1 * y1)
          else:
            loss = None
        if loss is not None:
          grad = g.gradient(loss, x1)
          if grad is not None:
            outputs.append(grad)
        del output_dtypes[:]
        output_dtypes.extend([t.dtype for t in outputs])
        return outputs

      # pylint: enable=cell-var-from-loop

      self._test_loop_fn(loop_fn, 3, loop_fn_dtypes=output_dtypes)

def random_normal(shape, mean=0.0, stddev=1.0, dtype=dtypes.float32, seed=None):
  """Tensor with (possibly complex) Gaussian entries.

  Samples are distributed like

  ```
  N(mean, stddev^2), if dtype is real,
  X + iY,  where X, Y ~ N(mean, stddev^2) if dtype is complex.
  ```

  Args:
    shape:  `TensorShape` or Python list.  Shape of the returned tensor.
    mean:  `Tensor` giving mean of normal to sample from.
    stddev:  `Tensor` giving stdev of normal to sample from.
    dtype:  `TensorFlow` `dtype` or numpy dtype
    seed:  Python integer seed for the RNG.

  Returns:
    `Tensor` with desired shape and dtype.
  """
  dtype = dtypes.as_dtype(dtype)

  with ops.name_scope("random_normal"):
    samples = random_ops.random_normal(
        shape, mean=mean, stddev=stddev, dtype=dtype.real_dtype, seed=seed)
    if dtype.is_complex:
      if seed is not None:
        seed += 1234
      more_samples = random_ops.random_normal(
          shape, mean=mean, stddev=stddev, dtype=dtype.real_dtype, seed=seed)
      samples = math_ops.complex(samples, more_samples)
    return samples

 def test_complex_tensor_with_imag_zero_doesnt_raise(self):
   x = ops.convert_to_tensor([1., 0, 3])
   y = ops.convert_to_tensor([0., 0, 0])
   z = math_ops.complex(x, y)
   with self.cached_session():
     # Should not raise.
     linear_operator_util.assert_zero_imag_part(z, message="ABC123").run()

 def test_complex_tensor_with_nonzero_imag_raises(self):
   x = ops.convert_to_tensor([1., 2, 0])
   y = ops.convert_to_tensor([1., 2, 0])
   z = math_ops.complex(x, y)
   with self.cached_session():
     with self.assertRaisesOpError("ABC123"):
       linear_operator_util.assert_zero_imag_part(z, message="ABC123").run()

  def _trace(self):
    # The diagonal of the [[nested] block] circulant operator is the mean of
    # the spectrum.
    # Proof:  For the [0,...,0] element, this follows from the IDFT formula.
    # Then the result follows since all diagonal elements are the same.

    # Therefore, the trace is the sum of the spectrum.

    # Get shape of diag along with the axis over which to reduce the spectrum.
    # We will reduce the spectrum over all block indices.
    if self.spectrum.get_shape().is_fully_defined():
      spec_rank = self.spectrum.get_shape().ndims
      axis = np.arange(spec_rank - self.block_depth, spec_rank, dtype=np.int32)
    else:
      spec_rank = array_ops.rank(self.spectrum)
      axis = math_ops.range(spec_rank - self.block_depth, spec_rank)

    # Real diag part "re_d".
    # Suppose spectrum.shape = [B1,...,Bb, N1, N2]
    # self.shape = [B1,...,Bb, N, N], with N1 * N2 = N.
    # re_d_value.shape = [B1,...,Bb]
    re_d_value = math_ops.reduce_sum(math_ops.real(self.spectrum), axis=axis)

    if not self.dtype.is_complex:
      return math_ops.cast(re_d_value, self.dtype)

    # Imaginary part, "im_d".
    if self.is_self_adjoint:
      im_d_value = 0.
    else:
      im_d_value = math_ops.reduce_sum(math_ops.imag(self.spectrum), axis=axis)

    return math_ops.cast(math_ops.complex(re_d_value, im_d_value), self.dtype)

 def test_zero_complex_tensor_raises(self):
   x = ops.convert_to_tensor([1., 2, 0])
   y = ops.convert_to_tensor([1., 2, 0])
   z = math_ops.complex(x, y)
   with self.test_session():
     with self.assertRaisesOpError("ABC123"):
       linear_operator_util.assert_no_entries_with_modulus_zero(
           z, message="ABC123").run()

 def test_assert_self_adjoint_does_not_raise_for_diag_with_zero_imag(self):
   with self.test_session():
     x = [1., 0.]
     y = [0., 0.]
     diag = math_ops.complex(x, y)
     operator = linalg.LinearOperatorDiag(diag)
     # Should not raise
     operator.assert_self_adjoint().run()

 def test_assert_self_adjoint_raises_if_diag_has_complex_part(self):
   with self.test_session():
     x = [1., 0.]
     y = [0., 1.]
     diag = math_ops.complex(x, y)
     operator = linalg.LinearOperatorDiag(diag)
     with self.assertRaisesOpError("imaginary.*not self-adjoint"):
       operator.assert_self_adjoint().run()

 def test_nonzero_complex_tensor_doesnt_raise(self):
   x = ops.convert_to_tensor([1., 0, 3])
   y = ops.convert_to_tensor([1., 2, 0])
   z = math_ops.complex(x, y)
   with self.cached_session():
     # Should not raise.
     linear_operator_util.assert_no_entries_with_modulus_zero(
         z, message="ABC123").run()

def dct(input, type=2, n=None, axis=-1, norm=None, name=None):  # pylint: disable=redefined-builtin
  """Computes the 1D [Discrete Cosine Transform (DCT)][dct] of `input`.

  Currently only Type II is supported. Implemented using a length `2N` padded
  @{tf.spectral.rfft}, as described here: https://dsp.stackexchange.com/a/10606

  @compatibility(scipy)
  Equivalent to scipy.fftpack.dct for the Type-II DCT.
  https://docs.scipy.org/doc/scipy-0.14.0/reference/generated/scipy.fftpack.dct.html
  @end_compatibility

  Args:
    input: A `[..., samples]` `float32` `Tensor` containing the signals to
      take the DCT of.
    type: The DCT type to perform. Must be 2.
    n: For future expansion. The length of the transform. Must be `None`.
    axis: For future expansion. The axis to compute the DCT along. Must be `-1`.
    norm: The normalization to apply. `None` for no normalization or `'ortho'`
      for orthonormal normalization.
    name: An optional name for the operation.

  Returns:
    A `[..., samples]` `float32` `Tensor` containing the DCT of `input`.

  Raises:
    ValueError: If `type` is not `2`, `n` is not `None, `axis` is not `-1`, or
      `norm` is not `None` or `'ortho'`.

  [dct]: https://en.wikipedia.org/wiki/Discrete_cosine_transform
  """
  _validate_dct_arguments(type, n, axis, norm)
  with _ops.name_scope(name, "dct", [input]):
    # We use the RFFT to compute the DCT and TensorFlow only supports float32
    # for FFTs at the moment.
    input = _ops.convert_to_tensor(input, dtype=_dtypes.float32)

    axis_dim = input.shape[-1].value or _array_ops.shape(input)[-1]
    axis_dim_float = _math_ops.to_float(axis_dim)
    scale = 2.0 * _math_ops.exp(_math_ops.complex(
        0.0, -_math.pi * _math_ops.range(axis_dim_float) /
        (2.0 * axis_dim_float)))

    # TODO(rjryan): Benchmark performance and memory usage of the various
    # approaches to computing a DCT via the RFFT.
    dct2 = _math_ops.real(
        rfft(input, fft_length=[2 * axis_dim])[..., :axis_dim] * scale)

    if norm == "ortho":
      n1 = 0.5 * _math_ops.rsqrt(axis_dim_float)
      n2 = n1 * _math_ops.sqrt(2.0)
      # Use tf.pad to make a vector of [n1, n2, n2, n2, ...].
      weights = _array_ops.pad(
          _array_ops.expand_dims(n1, 0), [[0, axis_dim - 1]],
          constant_values=n2)
      dct2 *= weights

    return dct2