analytics.py 文件源码

def band_center(spectrum, low_endmember=None, high_endmember=None, degree=3):
    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]

    fit = np.polyfit(ny.index, ny, degree)

    center_fit = Series(np.polyval(fit, ny.index), ny.index)
    center = band_minima(center_fit)

    return center, center_fit