code: func (d *DFT) IFFT() []float64 {
  	sndDataCmplx := fft.IFFT(d.Coefs)
  	sndData := make([]float64, len(sndDataCmplx))
  	for i, cpx := range sndDataCmplx {
  		sndData[i] = cmplx.Abs(cpx)
  	}
  	return sndData
  }
docs: // IFFT runs an inverse fast fourrier transform and returns the float values