From e5aeec49133ba19a381291ad6dcad1164d621c61 Mon Sep 17 00:00:00 2001
From: bma <baptiste.marechal@femto-st.fr>
Date: Wed, 4 Apr 2018 16:19:44 +0200
Subject: [PATCH] use real part

---
 allan_cov.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/allan_cov.m b/allan_cov.m
index f35537b..75da6ef 100644
--- a/allan_cov.m
+++ b/allan_cov.m
@@ -328,7 +328,7 @@ if isfield(data,'rate') && data.rate > 0 % if data rate was given
 		fd2=diff(fa2);
 		% calculate two-sample variance for this tau
 		M=length(fa);
-		sm(k)=sqrt(0.5/(M-1)*(real(sum(fd.*fd2))));
+		sm(k)=sqrt(0.5/(M-1)*abs(real(sum(fd.*fd2))));
 
 		% estimate error bars
 		sme(k)=sm(k)/sqrt(M+1);
-- 
2.16.4