lagrange.py 文件源码

def lagrange_interpolator(points, delta, delta_i_list):
    """
    Construct the multidimensional Lagrange interpolating polynomial
    defined by *delta* and *delta_i_list* at *points*.

    This is (7) in the reference

    Kamron Saniee, A Simple Expression for Multivariate Lagrange
    Interpolation, SIAM, 2007.
    """
    f = 0
    for i, delta_i in enumerate(delta_i_list):
        f += points[i][-1] * delta_i / delta
    # fix for corner case when polynomial reduces to a single float
    if isinstance(f, float):
        return SYM.Float(f)
    return f