Files
pytorch/torch/distributions/poisson.py
Maggie Moss b13cd141b3 Add pyrefly suppressions (#164748)
Adds suppressions to pyrefly will typecheck clean: https://github.com/pytorch/pytorch/issues/163283

Test plan:
dmypy restart && python3 scripts/lintrunner.py -a
pyrefly check

step 1: delete lines in the pyrefly.toml file from the `project-excludes` field
step 2: run pyrefly check
step 3: add suppressions, clean up unused suppressions
before: https://gist.github.com/maggiemoss/4b3bf2037014e116bc00706a16aef199

after:

0 errors (4,263 ignored)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/164748
Approved by: https://github.com/oulgen
2025-10-07 17:31:18 +00:00

89 lines
2.5 KiB
Python

# mypy: allow-untyped-defs
from typing import Optional, Union
import torch
from torch import Tensor
from torch.distributions import constraints
from torch.distributions.exp_family import ExponentialFamily
from torch.distributions.utils import broadcast_all
from torch.types import _Number, Number
__all__ = ["Poisson"]
class Poisson(ExponentialFamily):
r"""
Creates a Poisson distribution parameterized by :attr:`rate`, the rate parameter.
Samples are nonnegative integers, with a pmf given by
.. math::
\mathrm{rate}^k \frac{e^{-\mathrm{rate}}}{k!}
Example::
>>> # xdoctest: +SKIP("poisson_cpu not implemented for 'Long'")
>>> m = Poisson(torch.tensor([4]))
>>> m.sample()
tensor([ 3.])
Args:
rate (Number, Tensor): the rate parameter
"""
# pyrefly: ignore # bad-override
arg_constraints = {"rate": constraints.nonnegative}
support = constraints.nonnegative_integer
@property
def mean(self) -> Tensor:
return self.rate
@property
def mode(self) -> Tensor:
return self.rate.floor()
@property
def variance(self) -> Tensor:
return self.rate
def __init__(
self,
rate: Union[Tensor, Number],
validate_args: Optional[bool] = None,
) -> None:
(self.rate,) = broadcast_all(rate)
if isinstance(rate, _Number):
batch_shape = torch.Size()
else:
batch_shape = self.rate.size()
super().__init__(batch_shape, validate_args=validate_args)
def expand(self, batch_shape, _instance=None):
new = self._get_checked_instance(Poisson, _instance)
batch_shape = torch.Size(batch_shape)
new.rate = self.rate.expand(batch_shape)
super(Poisson, new).__init__(batch_shape, validate_args=False)
new._validate_args = self._validate_args
return new
def sample(self, sample_shape=torch.Size()):
shape = self._extended_shape(sample_shape)
with torch.no_grad():
return torch.poisson(self.rate.expand(shape))
def log_prob(self, value):
if self._validate_args:
self._validate_sample(value)
rate, value = broadcast_all(self.rate, value)
return value.xlogy(rate) - rate - (value + 1).lgamma()
@property
def _natural_params(self) -> tuple[Tensor]:
return (torch.log(self.rate),)
# pyrefly: ignore # bad-override
def _log_normalizer(self, x):
return torch.exp(x)