jax.random.poisson(key, lam, shape=None, dtype=<class 'int'>)[source]#

Sample Poisson random values with given shape and integer dtype.

The values are distributed according to the probability mass function:

\[f(k; \lambda) = \frac{\lambda^k e^{-\lambda}}{k!}\]

Where k is a non-negative integer and \(\lambda > 0\).

  • key (Array | ndarray | bool_ | number | bool | int | float | complex) – a PRNG key used as the random key.

  • lam (Array | ndarray | bool_ | number | bool | int | float | complex) – rate parameter (mean of the distribution), must be >= 0. Must be broadcast-compatible with shape

  • shape (Sequence[int] | None) – optional, a tuple of nonnegative integers representing the result shape. Default (None) produces a result shape equal to lam.shape.

  • dtype (str | type[Any] | dtype | SupportsDType) – optional, a integer dtype for the returned values (default int64 if jax_enable_x64 is true, otherwise int32).


A random array with the specified dtype and with shape given by shape if shape is not None, or else by ``lam.shape.

Return type: