How to use the aotools.fouriertransform.ift2 function in aotools

def test_ift2():
    data = numpy.zeros((10, 10))
    ift_data = fouriertransform.ift2(data, 1.)
    assert ift_data.shape == data.shape

mag = float(outputSpacing)/inputSpacing

    #Observation Plane Co-ords
    x2,y2 = numpy.meshgrid( outputSpacing*numpy.arange(-N/2,N/2),
                            outputSpacing*numpy.arange(-N/2,N/2) )
    r2sq = x2**2 + y2**2

    #Quadratic phase factors
    Q1 = numpy.exp( 1j * k/2. * (1-mag)/z * r1sq)

    Q2 = numpy.exp(-1j * numpy.pi**2 * 2 * z/mag/k*fsq)

    Q3 = numpy.exp(1j * k/2. * (mag-1)/(mag*z) * r2sq)

    #Compute propagated field
    outputComplexAmp = Q3 * fouriertransform.ift2(
                    Q2 * fouriertransform.ft2(Q1 * inputComplexAmp/mag,inputSpacing), df1)
    return outputComplexAmp

mag = float(outputSpacing)/inputSpacing

    #Observation Plane Co-ords
    x2,y2 = numpy.meshgrid( outputSpacing*numpy.arange(-N/2,N/2),
                            outputSpacing*numpy.arange(-N/2,N/2) )
    r2sq = x2**2 + y2**2

    #Quadratic phase factors
    Q1 = numpy.exp( 1j * k/2. * (1-mag)/z * r1sq)

    Q2 = numpy.exp(-1j * numpy.pi**2 * 2 * z/mag/k*fsq)

    Q3 = numpy.exp(1j * k/2. * (mag-1)/(mag*z) * r2sq)

    #Compute propagated field
    outputComplexAmp = Q3 * fouriertransform.ift2(
                    Q2 * fouriertransform.ft2(Q1 * inputComplexAmp/mag,inputSpacing), df1)
    return outputComplexAmp