FFT implementation in FlexPro

SupportCommunity FPScript FFT implementation in FlexPro

Ansicht von 3 Beiträgen - 1 bis 3 (von insgesamt 3)
  • Autor
    Beiträge
  • #12539
    Richard WeisangRichard Weisang
    Verwalter

    How is FFT implemented in FlexPro? The FlexPro FFT results I get differ from that in another software.

    #8202
    Richard WeisangRichard Weisang
    Verwalter

    How is FFT implemented in FlexPro? The FlexPro FFT results I get differ from that in another software.

    #8872
    Bernhard KantzBernhard Kantz
    Moderator

    Many FFT implementations return the magnitude spectrum which is not normalized. Our FFT returns the complex amplitudes which is the magnitude spectrum multiplied with 1/N. You can decide where you do the normalization – on the FFT or on the inverse. We do it on the FFT because then the complex spectrum returned directly corresponds to the amplitudes an phases of the sinusoids used to reconstruct the time signal.

    FFT
    y_k = 1/N Sum([j=0 to N-1] x_j * Exp(-2*Pi*i*j*k/N)

    IFFT
    x_j = Sum([k=0 to N-1] y_k * Exp(2*Pi*i*j*k/N)

    If you install the Spectral Analysis Option for FlexPro then you have an exact-n FFT available, which returns the magnitude spectrum instead of the complex amplitudes.

Ansicht von 3 Beiträgen - 1 bis 3 (von insgesamt 3)
  • Du musst angemeldet sein, um auf dieses Thema antworten zu können.