scalemixture.py 文件源码

def initial_values(self, tol=1e-10):
        """
        Generate initial values by doing fixed point
        iterations to solve for alpha
        """
        n, a, b = self.n, self.a, self.b

        if abs(b) < 1e-10:
            alpha = inv_psi(a / n)
        else:
            alpha = 1.

        z = tol + 1.

        while abs(z) > tol:

            z = n * psi(alpha) - \
                b / numpy.clip(alpha, 1e-300, 1e300) - a

            alpha -= z / (n * d_approx_psi(alpha) - b
                          / (alpha ** 2 + 1e-300))
            alpha = numpy.clip(alpha, 1e-100, 1e300)

        return numpy.clip(alpha - 1 / (n + 1e-300), 1e-100, 1e300), \
               alpha + 1 / (n + 1e-300), alpha