S11fit.py 文件源码

def diff_find_resonance(frec,diffS11,margin=31,doplots=False):
    """
    Returns the resonance frequency from maximum of the derivative of the phase
    """
    #Smooth data for initial guesses
    sReS11 = np.array(smooth(diffS11.real,margin,3))
    sImS11 = np.array(smooth(diffS11.imag,margin,3))
    sS11 = np.array( [x+1j*y for x,y in zip(sReS11,sImS11) ] )
    #Make smoothed phase vector removing 2pi jumps
    sArgS11 = np.angle(sS11)
    sArgS11 = np.unwrap(sArgS11)
    sdiffang = np.diff(sArgS11)

    #Get resonance index from maximum of the derivative of the phase
    avgph =  np.average(sdiffang)
    errvec = [np.power(x-avgph,2.) for x in sdiffang]
    ires = np.argmax(errvec[margin:-margin])+margin
    f0i=frec[ires]
    print("Max index: ",ires," Max frequency: ",f0i)

    if doplots:
        plt.title('Original signal (Re,Im)')
        plt.plot(frec,diffS11.real)
        plt.plot(frec,diffS11.imag)
        plt.plot(frec,np.abs(diffS11))
        plt.show()

        plt.plot(np.angle(sS11))
        plt.title('Smoothed Phase')
        plt.axis('auto')
        plt.show()
        plt.plot(sdiffang[margin:-margin])
        plt.title('Diff of Smoothed Phase')
        plt.show()

        plt.title('Smoothed (ph-phavg)\^2')
        plt.plot(errvec)
        plt.plot([ires],[errvec[ires]],'ro')
        plt.show()

    return f0i