tf.contrib.distributions.bijectors.Inline

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Class Inline

Bijector constructed from custom callables.

Inherits From: Bijector

Example Use:

exp = Inline(
  forward_fn=tf.exp,
  inverse_fn=tf.math.log,
  inverse_log_det_jacobian_fn=(
    lambda y: -tf.reduce_sum(tf.math.log(y), axis=-1)),
  name="exp")

The above example is equivalent to the Bijector Exp().

__init__

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__init__(
    forward_fn=None,
    inverse_fn=None,
    inverse_log_det_jacobian_fn=None,
    forward_log_det_jacobian_fn=None,
    forward_event_shape_fn=None,
    forward_event_shape_tensor_fn=None,
    inverse_event_shape_fn=None,
    inverse_event_shape_tensor_fn=None,
    is_constant_jacobian=False,
    validate_args=False,
    forward_min_event_ndims=None,
    inverse_min_event_ndims=None,
    name='inline'
)

Creates a Bijector from callables. (deprecated)

Args:

• forward_fn: Python callable implementing the forward transformation.
• inverse_fn: Python callable implementing the inverse transformation.
• inverse_log_det_jacobian_fn: Python callable implementing the log o det o jacobian of the inverse transformation.
• forward_log_det_jacobian_fn: Python callable implementing the log o det o jacobian of the forward transformation.
• forward_event_shape_fn: Python callable implementing non-identical static event shape changes. Default: shape is assumed unchanged.
• forward_event_shape_tensor_fn: Python callable implementing non-identical event shape changes. Default: shape is assumed unchanged.
• inverse_event_shape_fn: Python callable implementing non-identical static event shape changes. Default: shape is assumed unchanged.
• inverse_event_shape_tensor_fn: Python callable implementing non-identical event shape changes. Default: shape is assumed unchanged.
• is_constant_jacobian: Python bool indicating that the Jacobian is constant for all input arguments.
• validate_args: Python bool indicating whether arguments should be checked for correctness.
• forward_min_event_ndims: Python int indicating the minimal dimensionality this bijector acts on.
• inverse_min_event_ndims: Python int indicating the minimal dimensionality this bijector acts on.
• name: Python str, name given to ops managed by this object.

Properties

dtype

dtype of Tensors transformable by this distribution.

forward_min_event_ndims

Returns the minimal number of dimensions bijector.forward operates on.

graph_parents

Returns this Bijector's graph_parents as a Python list.

inverse_min_event_ndims

Returns the minimal number of dimensions bijector.inverse operates on.

is_constant_jacobian

Returns true iff the Jacobian matrix is not a function of x.

Returns:

• is_constant_jacobian: Python bool.

name

Returns the string name of this Bijector.

validate_args

Returns True if Tensor arguments will be validated.

Methods

tf.contrib.distributions.bijectors.Inline.forward

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forward(
    x,
    name='forward'
)

Returns the forward Bijector evaluation, i.e., X = g(Y).

Args:

• x: Tensor. The input to the "forward" evaluation.
• name: The name to give this op.

Returns:

Tensor.

Raises:

• TypeError: if self.dtype is specified and x.dtype is not self.dtype.
• NotImplementedError: if _forward is not implemented.

tf.contrib.distributions.bijectors.Inline.forward_event_shape

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forward_event_shape(input_shape)

Shape of a single sample from a single batch as a TensorShape.

Same meaning as forward_event_shape_tensor. May be only partially defined.

Args:

• input_shape: TensorShape indicating event-portion shape passed into forward function.

Returns:

• forward_event_shape_tensor: TensorShape indicating event-portion shape after applying forward. Possibly unknown.

tf.contrib.distributions.bijectors.Inline.forward_event_shape_tensor

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forward_event_shape_tensor(
    input_shape,
    name='forward_event_shape_tensor'
)

Shape of a single sample from a single batch as an int32 1D Tensor.

Args:

• input_shape: Tensor, int32 vector indicating event-portion shape passed into forward function.
• name: name to give to the op

Returns:

• forward_event_shape_tensor: Tensor, int32 vector indicating event-portion shape after applying forward.

tf.contrib.distributions.bijectors.Inline.forward_log_det_jacobian

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forward_log_det_jacobian(
    x,
    event_ndims,
    name='forward_log_det_jacobian'
)

Returns both the forward_log_det_jacobian.

Args:

• x: Tensor. The input to the "forward" Jacobian determinant evaluation.
• event_ndims: Number of dimensions in the probabilistic events being transformed. Must be greater than or equal to self.forward_min_event_ndims. The result is summed over the final dimensions to produce a scalar Jacobian determinant for each event, i.e. it has shape x.shape.ndims - event_ndims dimensions.
• name: The name to give this op.

Returns:

Tensor, if this bijector is injective. If not injective this is not implemented.

Raises:

• TypeError: if self.dtype is specified and y.dtype is not self.dtype.
• NotImplementedError: if neither _forward_log_det_jacobian nor {_inverse, _inverse_log_det_jacobian} are implemented, or this is a non-injective bijector.

tf.contrib.distributions.bijectors.Inline.inverse

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inverse(
    y,
    name='inverse'
)

Returns the inverse Bijector evaluation, i.e., X = g^{-1}(Y).

Args:

• y: Tensor. The input to the "inverse" evaluation.
• name: The name to give this op.

Returns:

Tensor, if this bijector is injective. If not injective, returns the k-tuple containing the unique k points (x1, ..., xk) such that g(xi) = y.

Raises:

• TypeError: if self.dtype is specified and y.dtype is not self.dtype.
• NotImplementedError: if _inverse is not implemented.

tf.contrib.distributions.bijectors.Inline.inverse_event_shape

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inverse_event_shape(output_shape)

Shape of a single sample from a single batch as a TensorShape.

Same meaning as inverse_event_shape_tensor. May be only partially defined.

Args:

• output_shape: TensorShape indicating event-portion shape passed into inverse function.

Returns:

• inverse_event_shape_tensor: TensorShape indicating event-portion shape after applying inverse. Possibly unknown.

tf.contrib.distributions.bijectors.Inline.inverse_event_shape_tensor

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inverse_event_shape_tensor(
    output_shape,
    name='inverse_event_shape_tensor'
)

Shape of a single sample from a single batch as an int32 1D Tensor.

Args:

• output_shape: Tensor, int32 vector indicating event-portion shape passed into inverse function.
• name: name to give to the op

Returns:

• inverse_event_shape_tensor: Tensor, int32 vector indicating event-portion shape after applying inverse.

tf.contrib.distributions.bijectors.Inline.inverse_log_det_jacobian

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inverse_log_det_jacobian(
    y,
    event_ndims,
    name='inverse_log_det_jacobian'
)

Returns the (log o det o Jacobian o inverse)(y).

Mathematically, returns: log(det(dX/dY))(Y). (Recall that: X=g^{-1}(Y).)

Note that forward_log_det_jacobian is the negative of this function, evaluated at g^{-1}(y).

Args:

• y: Tensor. The input to the "inverse" Jacobian determinant evaluation.
• event_ndims: Number of dimensions in the probabilistic events being transformed. Must be greater than or equal to self.inverse_min_event_ndims. The result is summed over the final dimensions to produce a scalar Jacobian determinant for each event, i.e. it has shape y.shape.ndims - event_ndims dimensions.
• name: The name to give this op.

Returns:

Tensor, if this bijector is injective. If not injective, returns the tuple of local log det Jacobians, log(det(Dg_i^{-1}(y))), where g_i is the restriction of g to the ith partition Di.

Raises:

• TypeError: if self.dtype is specified and y.dtype is not self.dtype.
• NotImplementedError: if _inverse_log_det_jacobian is not implemented.