Fix nyquist bin normalization

2026-02-16 01:59:00 +02:00 · 2026-02-16 01:59:00 +02:00 · 5610302c77
parent ce3f3c6221
commit 5610302c77
1 changed files with 6 additions and 0 deletions
--- a/src/frontend/com_fft.c
+++ b/src/frontend/com_fft.c
@ -189,6 +189,12 @@ com_fft(wordlist *wl)
            fdvec[i][j].cx_imag = out[j][1]/scale;
        }

+        /* for even-length input, the nyquist bin is paired with itself
+           and normalization does not require a factor of 2  */
+        if ( length % 2 == 0) {
+            fdvec[i][fpts-1].cx_real /= 2;
+            fdvec[i][fpts-1].cx_imag /= 2;
+        }
    }

    fftw_destroy_plan(plan_forward);