jax.random.dirichlet#

jax.random.dirichlet(key,alpha,shape=None,dtype=None)[source]#

Sample Dirichlet random values with given shape and float dtype.

The values are distributed according to the probability density function:

\[f(\{x_i\}; \{\alpha_i\}) \propto \prod_{i=1}^k x_i^{\alpha_i - 1}\]

Where\(k\) is the dimension, and\(\{x_i\}\) satisfies

\[\sum_{i=1}^k x_i = 1\]

and\(0 \le x_i \le 1\) for all\(x_i\).

Parameters:

• key (ArrayLike) – a PRNG key used as the random key.

• alpha (RealArray) – an array of shape(...,n) used as the concentrationparameter of the random variables.

• shape (Shape |None) – optional, a tuple of nonnegative integers specifying the resultbatch shape; that is, the prefix of the result shape excluding the lastelement of valuen. Must be broadcast-compatible withalpha.shape[:-1]. The default (None) produces a result shape equal toalpha.shape.

• dtype (DTypeLikeFloat |None) – optional, a float dtype for the returned values (default float64 ifjax_enable_x64 is true, otherwise float32).

Returns:

A random array with the specified dtype and shape given byshape+(alpha.shape[-1],) ifshape is not None, or elsealpha.shape.

Return type:

Array