numpy.random.RandomState.beta — NumPy v1.15 Manual (original) (raw)
RandomState. beta(a, b, size=None)¶
Draw samples from a Beta distribution.
The Beta distribution is a special case of the Dirichlet distribution, and is related to the Gamma distribution. It has the probability distribution function
f(x; a,b) = \frac{1}{B(\alpha, \beta)} x^{\alpha - 1} (1 - x)^{\beta - 1},
where the normalisation, B, is the beta function,
B(\alpha, \beta) = \int_0^1 t^{\alpha - 1} (1 - t)^{\beta - 1} dt.
It is often seen in Bayesian inference and order statistics.
| Parameters: | a : float or array_like of floats Alpha, non-negative. b : float or array_like of floats Beta, non-negative. size : int or tuple of ints, optional Output shape. If the given shape is, e.g., (m, n, k), thenm * n * k samples are drawn. If size is None (default), a single value is returned if a and b are both scalars. Otherwise, np.broadcast(a, b).size samples are drawn. |
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| Returns: | out : ndarray or scalar Drawn samples from the parameterized beta distribution. |