8.5.37 fft(self,chanList=[],phase=0,flag=0,$\backslash$

fft $<$ DataEntity: $<$ BoaDataEntity.py

        DES: plot FFT of signal
        INP: (int list) chanList = list of channels
             (int)         phase = phase to be plotted
             (int)          flag = flag to be used
             (logical)  optimize = if set, limit the computation to a power of 2
                                   elements