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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def stZCR(frame):
 """Computes zero crossing rate of frame"""

    count = len(frame)
    countZ = numpy.sum(numpy.abs(numpy.diff(numpy.sign(frame)))) / 2
    return (numpy.float64(countZ) / numpy.float64(count-1.0))