Madagascar Programming Reference Manual |
void kiss_fftr(kiss_fftr_cfg st,const kiss_fft_scalar *timedata,kiss_fft_cpx *fr eqdata) { /* input buffer timedata is stored row-wise */ /* The real part of the DC element of the frequency spectrum in st->tmpbuf * contains the sum of the even-numbered elements of the input time sequence * The imag part is the sum of the odd-numbered elements * * The sum of tdc.r and tdc.i is the sum of the input time sequence. * yielding DC of input time sequence * The difference of tdc.r - tdc.i is the sum of the input (dot product) [1,-1,1,-1... * yielding Nyquist bin of input time sequence */ ... }