From 5fe559194738e2e4c5df4196622211c0653ecf25 Mon Sep 17 00:00:00 2001
From: Paul Brossier <piem@piem.org>
Date: Sat, 8 Mar 2014 17:37:22 -0300
Subject: [PATCH] src/tempo/beattracking.c: improve confidence values by using
 interpolated peak magnitude and avoiding nan

---
 src/tempo/beattracking.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/tempo/beattracking.c b/src/tempo/beattracking.c
index 3f1708c4..5c5e01bb 100644
--- a/src/tempo/beattracking.c
+++ b/src/tempo/beattracking.c
@@ -421,8 +421,10 @@ smpl_t
 aubio_beattracking_get_confidence (aubio_beattracking_t * bt)
 {
   if (bt->gp) {
-    return fvec_max (bt->acfout) / fvec_sum(bt->acfout);
-  } else {
-    return 0.;
+    smpl_t acf_sum = fvec_sum(bt->acfout);
+    if (acf_sum != 0.) {
+      return fvec_quadratic_peak_mag (bt->acfout, bt->gp) / acf_sum;
+    }
   }
+  return 0.;
 }
-- 
2.11.0