# Copyright Contributors to the Pyro project.
# SPDX-License-Identifier: Apache-2.0
# The implementation follows the design in PyTorch: torch.distributions.constraints.py
#
# Copyright (c) 2016- Facebook, Inc (Adam Paszke)
# Copyright (c) 2014- Facebook, Inc (Soumith Chintala)
# Copyright (c) 2011-2014 Idiap Research Institute (Ronan Collobert)
# Copyright (c) 2012-2014 Deepmind Technologies (Koray Kavukcuoglu)
# Copyright (c) 2011-2012 NEC Laboratories America (Koray Kavukcuoglu)
# Copyright (c) 2011-2013 NYU (Clement Farabet)
# Copyright (c) 2006-2010 NEC Laboratories America (Ronan Collobert, Leon Bottou, Iain Melvin, Jason Weston)
# Copyright (c) 2006 Idiap Research Institute (Samy Bengio)
# Copyright (c) 2001-2004 Idiap Research Institute (Ronan Collobert, Samy Bengio, Johnny Mariethoz)
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
__all__ = [
"boolean",
"circular",
"complex",
"corr_cholesky",
"corr_matrix",
"dependent",
"greater_than",
"greater_than_eq",
"integer_interval",
"integer_greater_than",
"interval",
"is_dependent",
"l1_ball",
"less_than",
"lower_cholesky",
"multinomial",
"nonnegative",
"nonnegative_integer",
"ordered_vector",
"positive",
"positive_definite",
"positive_definite_circulant_vector",
"positive_semidefinite",
"positive_integer",
"real",
"real_vector",
"real_matrix",
"scaled_unit_lower_cholesky",
"simplex",
"sphere",
"softplus_lower_cholesky",
"softplus_positive",
"unit_interval",
"zero_sum",
"Constraint",
]
import math
from typing import Generic, Optional, cast
import numpy as np
import jax
import jax.numpy as jnp
from jax.tree_util import register_pytree_node
from jax.typing import ArrayLike
from numpyro._typing import NonScalarArray, NumLike, NumLikeT
from numpyro.distributions.util import array_equiv
[docs]
class Constraint(Generic[NumLikeT]):
"""
Abstract base class for constraints.
A constraint object represents a region over which a variable is valid,
e.g. within which a variable can be optimized.
"""
is_discrete: bool = False
event_dim: int = 0
def __init_subclass__(cls, **kwargs):
super().__init_subclass__(**kwargs)
register_pytree_node(cls, cls.tree_flatten, cls.tree_unflatten)
def __call__(self, x: NumLikeT) -> ArrayLike:
raise NotImplementedError
def __repr__(self) -> str:
return self.__class__.__name__[1:] + "()"
[docs]
def check(self, value: NumLikeT) -> ArrayLike:
"""
Returns a byte tensor of `sample_shape + batch_shape` indicating
whether each event in value satisfies this constraint.
"""
return self(value)
[docs]
def feasible_like(self, prototype: NumLikeT) -> NumLikeT:
"""
Get a feasible value which has the same shape as dtype as `prototype`.
"""
raise NotImplementedError
[docs]
def eq(self, other: object, static: bool = False) -> ArrayLike:
return self is other
def __eq__(self, other: object) -> bool:
return bool(self.eq(other, static=True))
[docs]
@classmethod
def tree_unflatten(cls, aux_data, params):
params_keys, aux_data = aux_data
self = cls.__new__(cls)
for k, v in zip(params_keys, params):
setattr(self, k, v)
for k, v in aux_data.items():
setattr(self, k, v)
return self
class ParameterFreeConstraint(Constraint[NumLikeT]):
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return isinstance(other, type(self))
class _SingletonConstraint(ParameterFreeConstraint[NumLikeT]):
"""
A constraint type which has only one canonical instance, like constraints.real,
and unlike constraints.interval.
"""
def __new__(cls):
if (not hasattr(cls, "_instance")) or (type(cls._instance) is not cls):
# Do not use the singleton instance of a superclass of cls.
cls._instance = super(_SingletonConstraint, cls).__new__(cls)
return cls._instance
class _Boolean(_SingletonConstraint[NumLike]):
is_discrete = True
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.equal(x, 0) | xp.equal(x, 1)
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.zeros_like(prototype)
class _CorrCholesky(_SingletonConstraint[NonScalarArray]):
event_dim = 2
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
tril = xp.tril(x)
lower_triangular = xp.all(xp.reshape(tril == x, x.shape[:-2] + (-1,)), axis=-1)
positive_diagonal = xp.all(xp.diagonal(x, axis1=-2, axis2=-1) > 0, axis=-1)
x_norm = xp.linalg.norm(x, axis=-1)
tol = xp.finfo(x.dtype).eps * x.shape[-1] * 10
unit_norm_row = xp.all(xp.abs(x_norm - 1) <= tol, axis=-1)
return lower_triangular & positive_diagonal & unit_norm_row
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.eye(prototype.shape[-1]), prototype.shape)
class _CorrMatrix(_SingletonConstraint[NonScalarArray]):
event_dim = 2
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
# check for symmetric
symmetric = xp.all(xp.isclose(x, xp.swapaxes(x, -2, -1)), axis=(-2, -1))
# check for the smallest eigenvalue is positive
positive = xp.linalg.eigvalsh(x)[..., 0] > 0
# check for diagonal equal to 1
unit_variance = xp.all(
xp.abs(xp.diagonal(x, axis1=-2, axis2=-1) - 1) < 1e-6, axis=-1
)
return symmetric & positive & unit_variance
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.eye(prototype.shape[-1]), prototype.shape)
class _Dependent(Constraint[NumLike]):
"""
Placeholder for variables whose support depends on other variables.
These variables obey no simple coordinate-wise constraints.
:param bool is_discrete: Optional value of ``.is_discrete`` in case this
can be computed statically. If not provided, access to the
``.is_discrete`` attribute will raise a NotImplementedError.
:param int event_dim: Optional value of ``.event_dim`` in case this can be
computed statically. If not provided, access to the ``.event_dim``
attribute will raise a NotImplementedError.
"""
def __init__(
self, *, is_discrete: bool = NotImplemented, event_dim: int = NotImplemented
):
self._is_discrete = is_discrete
self._event_dim = event_dim
super().__init__()
@property
def is_discrete(self) -> bool: # type: ignore[override]
if self._is_discrete is NotImplemented:
raise NotImplementedError(".is_discrete cannot be determined statically")
return self._is_discrete
@property
def event_dim(self) -> int: # type: ignore[override]
if self._event_dim is NotImplemented:
raise NotImplementedError(".event_dim cannot be determined statically")
return self._event_dim
def __call__(
self,
x: Optional[NumLike] = None,
*,
is_discrete: bool = NotImplemented,
event_dim: int = NotImplemented,
):
if x is not None:
raise ValueError("Cannot determine validity of dependent constraint")
# Support for syntax to customize static attributes::
# constraints.dependent(is_discrete=True, event_dim=1)
if is_discrete is NotImplemented:
is_discrete = self._is_discrete
if event_dim is NotImplemented:
event_dim = self._event_dim
return _Dependent(is_discrete=is_discrete, event_dim=event_dim)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _Dependent):
return False
return (
self._is_discrete == other._is_discrete
and self.event_dim == other._event_dim
)
def tree_flatten(self):
return (), (
(),
dict(_is_discrete=self._is_discrete, _event_dim=self.event_dim),
)
class dependent_property(property, _Dependent):
# XXX: this should not need to be pytree-able since it simply wraps a method
# and thus is automatically present once the method's object is created
def __init__(
self, fn=None, *, is_discrete=NotImplemented, event_dim=NotImplemented
):
super().__init__(fn)
self._is_discrete = is_discrete
self._event_dim = event_dim
def __call__(self, x):
if not callable(x):
return super().__call__(x)
# Support for syntax to customize static attributes::
# @constraints.dependent_property(is_discrete=True, event_dim=1)
# def support(self):
# ...
return dependent_property(
x, is_discrete=self._is_discrete, event_dim=self._event_dim
)
def is_dependent(constraint):
return isinstance(constraint, _Dependent)
class _GreaterThan(Constraint[NumLike]):
def __init__(self, lower_bound: NumLike) -> None:
self.lower_bound = lower_bound
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.greater(x, self.lower_bound)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(lower_bound={})".format(self.lower_bound)
return fmt_string
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.broadcast_to(self.lower_bound + 1, jnp.shape(prototype))
def tree_flatten(self):
return (self.lower_bound,), (("lower_bound",), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _GreaterThan):
return False
return array_equiv(self.lower_bound, other.lower_bound, static=static)
class _GreaterThanEq(_GreaterThan):
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.greater_equal(x, self.lower_bound)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _GreaterThanEq):
return False
return array_equiv(self.lower_bound, other.lower_bound, static=static)
class _Positive(_GreaterThan, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(0.0)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _GreaterThan.eq(self, other, static=static)
class _Nonnegative(_GreaterThanEq, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(0.0)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _GreaterThanEq.eq(self, other, static=static)
class _IndependentConstraint(Constraint[NumLikeT]):
"""
Wraps a constraint by aggregating over ``reinterpreted_batch_ndims``-many
dims in :meth:`check`, so that an event is valid only if all its
independent entries are valid.
"""
def __init__(
self, base_constraint: Constraint[NumLikeT], reinterpreted_batch_ndims: int
):
assert isinstance(base_constraint, Constraint)
assert isinstance(reinterpreted_batch_ndims, int)
assert reinterpreted_batch_ndims >= 0
if isinstance(base_constraint, _IndependentConstraint):
reinterpreted_batch_ndims = (
reinterpreted_batch_ndims + base_constraint.reinterpreted_batch_ndims
)
base_constraint = base_constraint.base_constraint
self.base_constraint: Constraint = base_constraint
self.reinterpreted_batch_ndims: int = reinterpreted_batch_ndims
super().__init__()
@property
def is_discrete(self) -> bool: # type: ignore[override]
return self.base_constraint.is_discrete
@property
def event_dim(self) -> int: # type: ignore[override]
return self.base_constraint.event_dim + self.reinterpreted_batch_ndims
def __call__(self, value: NumLikeT) -> ArrayLike:
result = self.base_constraint(value)
if self.reinterpreted_batch_ndims == 0:
return result
elif jnp.ndim(result) < self.reinterpreted_batch_ndims:
expected = self.event_dim
raise ValueError(
f"Expected value.dim() >= {expected} but got {jnp.ndim(value)}"
)
result = jnp.reshape(
result,
jnp.shape(result)[: jnp.ndim(result) - self.reinterpreted_batch_ndims]
+ (-1,),
)
result = result.all(-1)
return result
def __repr__(self) -> str:
return "{}({}, {})".format(
self.__class__.__name__[1:],
repr(self.base_constraint),
self.reinterpreted_batch_ndims,
)
def feasible_like(self, prototype: NumLikeT) -> NumLikeT:
return self.base_constraint.feasible_like(prototype)
def tree_flatten(self):
return (self.base_constraint,), (
("base_constraint",),
{"reinterpreted_batch_ndims": self.reinterpreted_batch_ndims},
)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _IndependentConstraint):
return False
if self.reinterpreted_batch_ndims != other.reinterpreted_batch_ndims:
return False
return self.base_constraint.eq(other.base_constraint, static=static)
class _RealVector(
_IndependentConstraint[NonScalarArray], _SingletonConstraint[NonScalarArray]
):
def __init__(self) -> None:
super().__init__(cast(Constraint[NonScalarArray], _Real()), 1)
class _RealMatrix(
_IndependentConstraint[NonScalarArray], _SingletonConstraint[NonScalarArray]
):
def __init__(self) -> None:
super().__init__(cast(Constraint[NonScalarArray], _Real()), 2)
class _LessThan(Constraint[NumLike]):
def __init__(self, upper_bound: NumLike) -> None:
self.upper_bound = upper_bound
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.less(x, self.upper_bound)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(upper_bound={})".format(self.upper_bound)
return fmt_string
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.broadcast_to(self.upper_bound - 1, jnp.shape(prototype))
def tree_flatten(self):
return (self.upper_bound,), (("upper_bound",), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _LessThan):
return False
return array_equiv(self.upper_bound, other.upper_bound, static=static)
class _LessThanEq(_LessThan):
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.less_equal(x, self.upper_bound)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _LessThanEq):
return False
return array_equiv(self.upper_bound, other.upper_bound, static=static)
class _IntegerInterval(Constraint[NumLike]):
is_discrete = True
def __init__(self, lower_bound: NumLike, upper_bound: NumLike) -> None:
self.lower_bound = lower_bound
self.upper_bound = upper_bound
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return (
xp.greater_equal(x, self.lower_bound)
& xp.less_equal(x, self.upper_bound)
& xp.equal(xp.mod(x, 1), 0)
)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(lower_bound={}, upper_bound={})".format(
self.lower_bound, self.upper_bound
)
return fmt_string
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.broadcast_to(self.lower_bound, jnp.shape(prototype))
def tree_flatten(self):
return (self.lower_bound, self.upper_bound), (
("lower_bound", "upper_bound"),
dict(),
)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _IntegerInterval):
return False
return array_equiv(
self.lower_bound, other.lower_bound, static=static
) & array_equiv(self.upper_bound, other.upper_bound, static=static)
class _IntegerGreaterThan(Constraint[NumLike]):
is_discrete = True
def __init__(self, lower_bound: NumLike) -> None:
self.lower_bound = lower_bound
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return (xp.mod(x, 1) == 0) & xp.greater_equal(x, self.lower_bound)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(lower_bound={})".format(self.lower_bound)
return fmt_string
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.broadcast_to(self.lower_bound, jnp.shape(prototype))
def tree_flatten(self):
return (self.lower_bound,), (("lower_bound",), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _IntegerGreaterThan):
return False
return array_equiv(self.lower_bound, other.lower_bound, static=static)
class _IntegerPositive(_IntegerGreaterThan, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(1)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _IntegerGreaterThan.eq(self, other, static=static)
class _IntegerNonnegative(_IntegerGreaterThan, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(0)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _IntegerGreaterThan.eq(self, other, static=static)
class _Interval(Constraint[NumLike]):
def __init__(self, lower_bound: NumLike, upper_bound: NumLike) -> None:
self.lower_bound = lower_bound
self.upper_bound = upper_bound
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.greater_equal(x, self.lower_bound) & xp.less_equal(
x, self.upper_bound
)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(lower_bound={}, upper_bound={})".format(
self.lower_bound, self.upper_bound
)
return fmt_string
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.broadcast_to(
(self.lower_bound + self.upper_bound) / 2, jnp.shape(prototype)
)
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _Interval):
return False
return array_equiv(
self.lower_bound, other.lower_bound, static=static
) & array_equiv(self.upper_bound, other.upper_bound, static=static)
def tree_flatten(self):
return (self.lower_bound, self.upper_bound), (
("lower_bound", "upper_bound"),
dict(),
)
class _Circular(_Interval, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(-math.pi, math.pi)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _Interval.eq(self, other, static=static)
class _UnitInterval(_Interval, _SingletonConstraint[NumLike]):
def __init__(self) -> None:
super().__init__(0.0, 1.0)
def tree_flatten(self):
return (), ((), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
return _Interval.eq(self, other, static=static)
class _OpenInterval(_Interval):
def __call__(self, x: NumLike) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return xp.greater(x, self.lower_bound) & xp.less(x, self.upper_bound)
def __repr__(self) -> str:
fmt_string = self.__class__.__name__[1:]
fmt_string += "(lower_bound={}, upper_bound={})".format(
self.lower_bound, self.upper_bound
)
return fmt_string
class _LowerCholesky(_SingletonConstraint[NonScalarArray]):
event_dim = 2
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
tril = xp.tril(x)
lower_triangular = xp.all(xp.reshape(tril == x, x.shape[:-2] + (-1,)), axis=-1)
positive_diagonal = xp.all(xp.diagonal(x, axis1=-2, axis2=-1) > 0, axis=-1)
return lower_triangular & positive_diagonal
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.eye(prototype.shape[-1]), prototype.shape)
class _Multinomial(Constraint[NonScalarArray]):
is_discrete = True
event_dim = 1
def __init__(self, upper_bound: ArrayLike) -> None:
self.upper_bound = upper_bound
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = jnp if isinstance(x, jax.Array) else np
return (x >= 0).all(axis=-1) & xp.equal(x.sum(axis=-1), self.upper_bound)
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
pad_width = ((0, 0),) * jnp.ndim(self.upper_bound) + (
(0, prototype.shape[-1] - 1),
)
value = jnp.pad(jnp.expand_dims(self.upper_bound, -1), pad_width)
return jnp.broadcast_to(value, prototype.shape)
def tree_flatten(self):
return (self.upper_bound,), (("upper_bound",), dict())
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _Multinomial):
return False
return array_equiv(self.upper_bound, other.upper_bound, static=static)
class _L1Ball(_SingletonConstraint[NumLike]):
"""
Constrain to the L1 ball of any dimension.
"""
event_dim = 1
reltol = 10.0 # Relative to finfo.eps.
def __call__(self, x: NumLike) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
eps = xp.finfo(x.dtype if isinstance(x, xp.ndarray) else type(x)).eps
return xp.abs(x).sum(axis=-1) < 1 + self.reltol * eps
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.zeros_like(prototype)
class _OrderedVector(_SingletonConstraint[NonScalarArray]):
event_dim = 1
def __call__(self, x: NonScalarArray) -> ArrayLike:
return (x[..., 1:] > x[..., :-1]).all(axis=-1)
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.arange(float(prototype.shape[-1])), prototype.shape)
class _PositiveDefinite(_SingletonConstraint[NonScalarArray]):
event_dim = 2
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
# check for symmetric
symmetric = xp.all(xp.isclose(x, xp.swapaxes(x, -2, -1)), axis=(-2, -1))
# check for the smallest eigenvalue is positive
positive = xp.linalg.eigh(x)[0][..., 0] > 0
return symmetric & positive
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.eye(prototype.shape[-1]), prototype.shape)
class _PositiveDefiniteCirculantVector(_SingletonConstraint[NonScalarArray]):
event_dim = 1
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
tol = 10 * xp.finfo(x.dtype).eps
rfft = xp.fft.rfft(x)
return (xp.abs(rfft.imag) < tol) & (rfft.real > -tol)
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.zeros_like(prototype).at[..., 0].set(1.0)
class _PositiveSemiDefinite(_SingletonConstraint[NonScalarArray]):
event_dim = 2
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
# check for symmetric
symmetric = xp.all(xp.isclose(x, xp.swapaxes(x, -2, -1)), axis=(-2, -1))
# check for the smallest eigenvalue is nonnegative
nonnegative = xp.linalg.eigh(x)[0][..., 0] >= 0
return symmetric & nonnegative
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(jnp.eye(prototype.shape[-1]), prototype.shape)
class _PositiveOrderedVector(_SingletonConstraint[NonScalarArray]):
"""
Constrains to a positive real-valued tensor where the elements are monotonically
increasing along the `event_shape` dimension.
"""
event_dim = 1
def __call__(self, x: NonScalarArray) -> ArrayLike:
return jnp.logical_and(
ordered_vector.check(x), jnp.all(positive.check(x), axis=-1)
)
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(
jnp.exp(jnp.arange(float(prototype.shape[-1]))), prototype.shape
)
class _Complex(_SingletonConstraint[NumLike]):
def __call__(self, x: NumLike) -> ArrayLike:
# XXX: consider to relax this condition to [-inf, inf] interval
xp = jnp if isinstance(x, jax.Array) else np
return (
xp.equal(x, x)
& xp.not_equal(x, float("inf"))
& xp.not_equal(x, float("-inf"))
)
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.zeros_like(prototype)
class _Real(_SingletonConstraint[NumLike]):
def __call__(self, x: NumLike) -> ArrayLike:
# XXX: consider to relax this condition to [-inf, inf] interval
return (x == x) & (x != float("inf")) & (x != float("-inf"))
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.zeros_like(prototype)
class _Simplex(_SingletonConstraint[NonScalarArray]):
event_dim = 1
def __call__(self, x: NonScalarArray) -> ArrayLike:
x_sum = x.sum(axis=-1)
return (x >= 0).all(axis=-1) & (x_sum < 1 + 1e-6) & (x_sum > 1 - 1e-6)
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.full_like(prototype, 1 / prototype.shape[-1])
class _SoftplusPositive(_SingletonConstraint[NumLike], _GreaterThan):
def __init__(self) -> None:
super().__init__(lower_bound=0.0)
def feasible_like(self, prototype: NumLike) -> NumLike:
return jnp.full(jnp.shape(prototype), np.log(2))
class _SoftplusLowerCholesky(_LowerCholesky):
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.broadcast_to(
jnp.eye(prototype.shape[-1]) * np.log(2), prototype.shape
)
class _ScaledUnitLowerCholesky(_LowerCholesky):
pass
class _Sphere(_SingletonConstraint[NonScalarArray]):
"""
Constrain to the Euclidean sphere of any dimension.
"""
event_dim = 1
reltol = 10.0 # Relative to finfo.eps.
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
eps = xp.finfo(x.dtype).eps
norm = xp.linalg.norm(x, axis=-1)
error = xp.abs(norm - 1)
return error < self.reltol * eps * x.shape[-1] ** 0.5
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.full_like(prototype, prototype.shape[-1] ** (-0.5))
class _ZeroSum(Constraint[NonScalarArray]):
def __init__(self, event_dim: int = 1) -> None:
self._event_dim = event_dim
super().__init__()
@property
def event_dim(self) -> int: # type: ignore[override]
return self._event_dim
def __call__(self, x: NonScalarArray) -> ArrayLike:
xp = np if isinstance(x, (np.ndarray, np.generic)) else jnp
tol = xp.finfo(x.dtype).eps * x.shape[-1] * 10
zerosum_true = True
for dim in range(-self.event_dim, 0):
zerosum_true = zerosum_true & xp.allclose(x.sum(dim), 0, atol=tol)
return zerosum_true
def eq(self, other: object, static: bool = False) -> ArrayLike:
if not isinstance(other, _ZeroSum):
return False
return self.event_dim == other.event_dim
def feasible_like(self, prototype: NonScalarArray) -> NonScalarArray:
return jnp.zeros_like(prototype)
def tree_flatten(self):
return (), ((), {"_event_dim": self._event_dim})
# TODO: Make types consistent
# See https://github.com/pytorch/pytorch/issues/50616
boolean = _Boolean()
circular = _Circular()
complex = _Complex()
corr_cholesky = _CorrCholesky()
corr_matrix = _CorrMatrix()
dependent: _Dependent = _Dependent()
greater_than = _GreaterThan
greater_than_eq = _GreaterThanEq
less_than = _LessThan
less_than_eq = _LessThanEq
independent = _IndependentConstraint
integer_interval = _IntegerInterval
integer_greater_than = _IntegerGreaterThan
interval = _Interval
l1_ball = _L1Ball()
lower_cholesky = _LowerCholesky()
scaled_unit_lower_cholesky = _ScaledUnitLowerCholesky()
multinomial = _Multinomial
nonnegative = _Nonnegative()
nonnegative_integer = _IntegerNonnegative()
ordered_vector = _OrderedVector()
positive = _Positive()
positive_definite = _PositiveDefinite()
positive_definite_circulant_vector = _PositiveDefiniteCirculantVector()
positive_semidefinite = _PositiveSemiDefinite()
positive_integer = _IntegerPositive()
positive_ordered_vector = _PositiveOrderedVector()
real = _Real()
real_vector = _RealVector()
real_matrix = _RealMatrix()
simplex = _Simplex()
softplus_lower_cholesky = _SoftplusLowerCholesky()
softplus_positive = _SoftplusPositive()
sphere = _Sphere()
unit_interval = _UnitInterval()
open_interval = _OpenInterval
zero_sum = _ZeroSum