This Bijector is initialized with shift Tensor and scale arguments, giving the forward operation: Y = g(X) = scale @ X + shift where the scale term is logically equivalent to: scale = scale_identity_multiplier * tf.diag(tf.ones(d)) + tf.diag(scale_diag) + scale_tril + scale_perturb_factor @ diag(scale_perturb_diag) @ tf.transpose([scale_perturb_factor]))

tfb_affine(
  shift = NULL,
  scale_identity_multiplier = NULL,
  scale_diag = NULL,
  scale_tril = NULL,
  scale_perturb_factor = NULL,
  scale_perturb_diag = NULL,
  adjoint = FALSE,
  validate_args = FALSE,
  name = "affine",
  dtype = NULL
)

Arguments

shift

Floating-point Tensor. If this is set to NULL, no shift is applied.

scale_identity_multiplier

floating point rank 0 Tensor representing a scaling done to the identity matrix. When scale_identity_multiplier = scale_diag = scale_tril = NULL then scale += IdentityMatrix. Otherwise no scaled-identity-matrix is added to scale.

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 NULL no diagonal term is added to scale.

scale_tril

Floating-point Tensor representing the lower triangular matrix. scale_tril has shape [N1, N2, ... k, k], which represents a k x k lower triangular matrix. When NULL no scale_tril term is added to scale. The upper triangular elements above the diagonal are ignored.

scale_perturb_factor

Floating-point Tensor representing factor matrix with last two dimensions of shape (k, r) When NULL, no rank-r update is added to scale.

scale_perturb_diag

Floating-point Tensor representing the diagonal matrix. scale_perturb_diag has shape [N1, N2, ... r], which represents an r x r diagonal matrix. When NULL low rank updates will take the form scale_perturb_factor * scale_perturb_factor.T.

adjoint

Logical indicating whether to use the scale matrix as specified or its adjoint. Default value: FALSE.

validate_args

Logical, default FALSE. Whether to validate input with asserts. If validate_args is FALSE, and the inputs are invalid, correct behavior is not guaranteed.

name

name prefixed to Ops created by this class.

dtype

tf$DType to prefer when converting args to Tensors. Else, we fall back to a common dtype inferred from the args, finally falling back to float32.

Value

a bijector instance.

Details

If NULL of scale_identity_multiplier, scale_diag, or scale_tril are specified then scale += IdentityMatrix Otherwise specifying a scale argument has the semantics of scale += Expand(arg), i.e., scale_diag != NULL means scale += tf$diag(scale_diag).

See also