dirichlet.py 文件源码

def _variance(self):
    scale = self.alpha_sum * math_ops.sqrt(1. + self.alpha_sum)
    alpha = self.alpha / scale
    outer_prod = -math_ops.batch_matmul(
        array_ops.expand_dims(alpha, dim=-1),  # column
        array_ops.expand_dims(alpha, dim=-2))  # row
    return array_ops.matrix_set_diag(outer_prod,
                                     alpha * (self.alpha_sum / scale - alpha))