transforms.py 文件源码

def downsampleBy(v, factor):
    order = 8   # default value for decimate() anyway
    minSamples = 5
    if len(v) < (minSamples * factor):
        factor = int(len(v) / minSamples)
    v = signal.decimate(v, factor, n=order)
    if len(v) >= (order + minSamples):
        return v[(order - 1):]
    return v