tone_est_ok.py 文件源码

def est_tone_phase(sdata,a,f,sr):
    samples = len(sdata)
    points  = 360
    rms = numpy.zeros(points)
    sum_min = numpy.sum(numpy.square(sdata))
    min_index = 0
    for offset in xrange(points):
        sum = 0
        phase = pi*offset/180.0
        for i in xrange(samples):
            diff = (sdata[i] - a*cos(2*pi*i*f/(sr/2.0) + phase))
            sum += diff*diff
        rms[offset] = sum
        if (sum < sum_min):
            sum_min = sum
            min_index = offset
            #print "sum_min",sum_min,' index = ',min_index

    min_phase = pi*(min_index)/180.0
    #print "min for phase sweep is ",sum_min,' at offset ',min_index
    return min_phase