Module « numpy.random »

Fonction beta - module numpy.random

Signature de la fonction beta

Description

beta.__doc__

        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

        .. math:: f(x; a,b) = \frac{1}{B(\alpha, \beta)} x^{\alpha - 1}
                                                         (1 - x)^{\beta - 1},

        where the normalization, B, is the beta function,

        .. math:: B(\alpha, \beta) = \int_0^1 t^{\alpha - 1}
                                     (1 - t)^{\beta - 1} dt.

        It is often seen in Bayesian inference and order statistics.

        .. note::
            New code should use the ``beta`` method of a ``default_rng()``
            instance instead; please see the :ref:`random-quick-start`.

        Parameters
        ----------
        a : float or array_like of floats
            Alpha, positive (>0).
        b : float or array_like of floats
            Beta, positive (>0).
        size : int or tuple of ints, optional
            Output shape.  If the given shape is, e.g., ``(m, n, k)``, then
            ``m * 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.

        Returns
        -------
        out : ndarray or scalar
            Drawn samples from the parameterized beta distribution.

        See Also
        --------
        Generator.beta: which should be used for new code.