util.py 文件源码

def derampMatrix(displ):
    """ Deramp through fitting a bilinear plane
    Data is also de-meaned
    """
    if displ.ndim != 2:
        raise TypeError('Displacement has to be 2-dim array')
    mx = num.nanmedian(displ, axis=0)
    my = num.nanmedian(displ, axis=1)

    ix = num.arange(mx.size)
    iy = num.arange(my.size)
    dx, cx, _, _, _ = sp.stats.linregress(ix[~num.isnan(mx)],
                                          mx[~num.isnan(mx)])
    dy, cy, _, _, _ = sp.stats.linregress(iy[~num.isnan(my)],
                                          my[~num.isnan(my)])

    rx = (ix * dx)
    ry = (iy * dy)
    data = displ - (rx[num.newaxis, :] + ry[:, num.newaxis])
    data -= num.nanmean(data)
    return data