From ce3f3c6221459ce1abeb39990f0f037d792251d0 Mon Sep 17 00:00:00 2001
From: Gerald Fournier <>
Date: Mon, 16 Feb 2026 00:02:20 +0200
Subject: [PATCH] Fix FFT normalization

---
 src/frontend/com_fft.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/frontend/com_fft.c b/src/frontend/com_fft.c
index 82ea72ca8..df73946a7 100644
--- a/src/frontend/com_fft.c
+++ b/src/frontend/com_fft.c
@@ -181,7 +181,7 @@ com_fft(wordlist *wl)
 
         fftw_execute(plan_forward);
 
-        scale = (double) fpts - 1.0;
+        scale = (double) (length*1.0/2.0);
         fdvec[i][0].cx_real = out[0][0]/scale/2.0;
         fdvec[i][0].cx_imag = 0.0;
         for (j = 1; j < fpts; j++) {
@@ -215,7 +215,7 @@ com_fft(wordlist *wl)
         rffts(in, M, 1);
         fftFree();
 
-        scale = (double) fpts - 1.0;
+        scale = (double) (length*1.0/2.0);
         /* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
         fdvec[i][0].cx_real = in[0]/scale/2.0;
         fdvec[i][0].cx_imag = 0.0;