def testDiag(self):
with self.test_session():
shift = np.array([-1, 0, 1], dtype=np.float32)
diag = np.array([[1, 2, 3],
[2, 5, 6]], dtype=np.float32)
scale = linalg.LinearOperatorDiag(diag, is_non_singular=True)
affine = affine_linear_operator_lib.AffineLinearOperator(
shift=shift, scale=scale, validate_args=True)
x = np.array([[1, 0, -1], [2, 3, 4]], dtype=np.float32)
y = diag * x + shift
ildj = -np.sum(np.log(np.abs(diag)), axis=-1)
self.assertEqual(affine.name, "affine_linear_operator")
self.assertAllClose(y, affine.forward(x).eval())
self.assertAllClose(x, affine.inverse(y).eval())
self.assertAllClose(ildj, affine.inverse_log_det_jacobian(y).eval())
self.assertAllClose(-affine.inverse_log_det_jacobian(y).eval(),
affine.forward_log_det_jacobian(x).eval())
def make_diag_scale(loc=None,
scale_diag=None,
scale_identity_multiplier=None,
shape_hint=None,
validate_args=False,
assert_positive=False,
name=None):
"""Creates a LinOp representing a diagonal matrix.
Args:
loc: Floating-point `Tensor`. This is used for inferring shape in the case
where only `scale_identity_multiplier` is set.
scale_diag: Floating-point `Tensor` representing the diagonal matrix.
`scale_diag` has shape [N1, N2, ... k], which represents a k x k
diagonal matrix.
When `None` no diagonal term is added to the LinOp.
scale_identity_multiplier: floating point rank 0 `Tensor` representing a
scaling done to the identity matrix.
When `scale_identity_multiplier = scale_diag = scale_tril = None` then
`scale += IdentityMatrix`. Otherwise no scaled-identity-matrix is added
to `scale`.
shape_hint: scalar integer `Tensor` representing a hint at the dimension of
the identity matrix when only `scale_identity_multiplier` is set.
validate_args: Python `bool` indicating whether arguments should be
checked for correctness.
assert_positive: Python `bool` indicating whether LinOp should be checked
for being positive definite.
name: Python `str` name given to ops managed by this object.
Returns:
`LinearOperator` representing a lower triangular matrix.
Raises:
ValueError: If only `scale_identity_multiplier` is set and `loc` and
`shape_hint` are both None.
"""
def _maybe_attach_assertion(x):
if not validate_args:
return x
if assert_positive:
return control_flow_ops.with_dependencies([
check_ops.assert_positive(
x, message="diagonal part must be positive"),
], x)
return control_flow_ops.with_dependencies([
check_ops.assert_none_equal(
x,
array_ops.zeros([], x.dtype),
message="diagonal part must be non-zero")
], x)
with ops.name_scope(name,
"make_diag_scale",
values=[loc, scale_diag, scale_identity_multiplier]):
loc = _convert_to_tensor(loc, name="loc")
scale_diag = _convert_to_tensor(scale_diag, name="scale_diag")
scale_identity_multiplier = _convert_to_tensor(
scale_identity_multiplier, name="scale_identity_multiplier")
if scale_diag is not None:
if scale_identity_multiplier is not None:
scale_diag += scale_identity_multiplier[..., array_ops.newaxis]
return linalg.LinearOperatorDiag(
diag=_maybe_attach_assertion(scale_diag),
is_non_singular=True,
is_self_adjoint=True,
is_positive_definite=assert_positive)
if loc is None and shape_hint is None:
raise ValueError("Cannot infer `event_shape` unless `loc` or "
"`shape_hint` is specified.")
if shape_hint is None:
shape_hint = loc.shape[-1]
if scale_identity_multiplier is None:
return linalg.LinearOperatorIdentity(
num_rows=shape_hint,
dtype=loc.dtype.base_dtype,
is_self_adjoint=True,
is_positive_definite=True,
assert_proper_shapes=validate_args)
return linalg.LinearOperatorScaledIdentity(
num_rows=shape_hint,
multiplier=_maybe_attach_assertion(scale_identity_multiplier),
is_non_singular=True,
is_self_adjoint=True,
is_positive_definite=assert_positive,
assert_proper_shapes=validate_args)
def make_diag_scale(loc,
scale_diag,
scale_identity_multiplier,
validate_args,
assert_positive,
name=None):
"""Creates a LinOp from `scale_diag`, `scale_identity_multiplier` kwargs."""
def _convert_to_tensor(x, name):
return None if x is None else ops.convert_to_tensor(x, name=name)
def _maybe_attach_assertion(x):
if not validate_args:
return x
if assert_positive:
return control_flow_ops.with_dependencies([
check_ops.assert_positive(
x, message="diagonal part must be positive"),
], x)
# TODO(b/35157376): Use `assert_none_equal` once it exists.
return control_flow_ops.with_dependencies([
check_ops.assert_greater(math_ops.abs(x),
array_ops.zeros([], x.dtype),
message="diagonal part must be non-zero"),
], x)
with ops.name_scope(name,
"make_diag_scale",
values=[loc, scale_diag, scale_identity_multiplier]):
loc = _convert_to_tensor(loc, name="loc")
scale_diag = _convert_to_tensor(scale_diag, name="scale_diag")
scale_identity_multiplier = _convert_to_tensor(
scale_identity_multiplier, name="scale_identity_multiplier")
if scale_diag is not None:
if scale_identity_multiplier is not None:
scale_diag += scale_identity_multiplier[..., array_ops.newaxis]
return linalg.LinearOperatorDiag(
diag=_maybe_attach_assertion(scale_diag),
is_non_singular=True,
is_self_adjoint=True,
is_positive_definite=assert_positive)
# TODO(b/35290280): Consider inferring shape from scale_perturb_factor.
if loc is None:
raise ValueError(
"Cannot infer `event_shape` unless `loc` is specified.")
num_rows = dimension_size(loc, -1)
if scale_identity_multiplier is None:
return linalg.LinearOperatorIdentity(
num_rows=num_rows,
dtype=loc.dtype.base_dtype,
is_self_adjoint=True,
is_positive_definite=True,
assert_proper_shapes=validate_args)
return linalg.LinearOperatorScaledIdentity(
num_rows=num_rows,
multiplier=_maybe_attach_assertion(scale_identity_multiplier),
is_non_singular=True,
is_self_adjoint=True,
is_positive_definite=assert_positive,
assert_proper_shapes=validate_args)
