schemes.py 文件源码

def _gauss_from_coefficients_numpy(alpha, beta):
    assert isinstance(alpha, numpy.ndarray)
    assert isinstance(beta, numpy.ndarray)

    # eigh_tridiagonal is only available from scipy 1.0.0
    try:
        from scipy.linalg import eigh_tridiagonal
    except ImportError:
        # Use eig_banded
        x, V = eig_banded(numpy.vstack((numpy.sqrt(beta), alpha)), lower=False)
        w = beta[0]*scipy.real(scipy.power(V[0, :], 2))
    else:
        x, V = eigh_tridiagonal(alpha, numpy.sqrt(beta[1:]))
        w = beta[0] * V[0, :]**2

    return x, w