jax.random.lognormal(key, sigma=1.0, shape=None, dtype=<class 'float'>)[source]#

Sample lognormal random values with given shape and float dtype.

The values are distributed according to the probability density function:

\[f(x) = \frac{1}{x\sqrt{2\pi\sigma^2}}\exp\left(-\frac{(\log x)^2}{2\sigma^2}\right)\]

on the domain \(x > 0\).

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

  • sigma (Array | ndarray | bool_ | number | bool | int | float | complex) – a float or array of floats broadcast-compatible with shape representing the standard deviation of the underlying normal distribution. Default 1.

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

  • dtype (str | type[Any] | dtype | SupportsDType) – optional, a float dtype for the returned values (default float64 if jax_enable_x64 is true, otherwise float32).


A random array with the specified dtype and with shape given by shape.

Return type: