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correct fft scaling at Nyquist freq. in fft cmd and vector operation

This commit is contained in:
dwarning 2026-03-01 16:18:24 +01:00
parent 5e82b63f62
commit d2b1ecbb23
2 changed files with 6 additions and 2 deletions
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4
src/frontend/com_fft.c
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@ -181,10 +181,12 @@ com_fft(wordlist *wl)
scale = (double) fpts - 1.0; scale = (double) fpts - 1.0;
fdvec[i][0].cx_real = out[0][0]/scale/2.0; fdvec[i][0].cx_real = out[0][0]/scale/2.0;
fdvec[i][0].cx_imag = 0.0; fdvec[i][0].cx_imag = 0.0;
for (j = 1; j < fpts; j++) { for (j = 1; j < fpts-1; j++) {
fdvec[i][j].cx_real = out[j][0]/scale; fdvec[i][j].cx_real = out[j][0]/scale;
fdvec[i][j].cx_imag = out[j][1]/scale; fdvec[i][j].cx_imag = out[j][1]/scale;
} }
fdvec[i][fpts-1].cx_real = out[fpts-1][0]/scale/2.0;
fdvec[i][fpts-1].cx_imag = 0.0;
} }

4
src/maths/cmaths/cmath4.c
View File

@ -777,10 +777,12 @@ cx_fft(void *data, short int type, int length, int *newlength, short int *newtyp
scale = (double) fpts - 1.0; scale = (double) fpts - 1.0;
outdata[0].cx_real = out[0][0]/scale/2.0; outdata[0].cx_real = out[0][0]/scale/2.0;
outdata[0].cx_imag = 0.0; outdata[0].cx_imag = 0.0;
for (i = 1; i < fpts; i++) { for (i = 1; i < fpts-1; i++) {
outdata[i].cx_real = out[i][0]/scale; outdata[i].cx_real = out[i][0]/scale;
outdata[i].cx_imag = out[i][1]/scale; outdata[i].cx_imag = out[i][1]/scale;
} }
outdata[fpts-1].cx_real = out[fpts-1][0]/scale/2.0;
outdata[fpts-1].cx_imag = 0.0;
fftw_free(ind); fftw_free(ind);