analytics.py 文件源码

def band_area(spectrum, low_endmember=None, high_endmember=None):
    """
    Compute the area under the curve between two endpoints where the
    y-value <= 1.
    """

    x = spectrum.index
    y = spectrum

    if not low_endmember:
        low_endmember = x[0]
    if not high_endmember:
        high_endmember = x[-1]

    ny = y[low_endmember:high_endmember]

    return np.trapz(-ny[ny <= 1.0])