From a2b43805114b4bd01cf11f139f2d254ade7960b1 Mon Sep 17 00:00:00 2001
From: UAEDF-tomc <tom.cornelis@ua.ac.be>
Date: Mon, 5 May 2014 16:05:07 +0200
Subject: [PATCH] Make use of reco::deltaPhi

---
 RecoJets/JetProducers/plugins/QGTagger.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/RecoJets/JetProducers/plugins/QGTagger.cc b/RecoJets/JetProducers/plugins/QGTagger.cc
index 0285e8d2adb07..49f55b464d046 100644
--- a/RecoJets/JetProducers/plugins/QGTagger.cc
+++ b/RecoJets/JetProducers/plugins/QGTagger.cc
@@ -14,6 +14,7 @@
 #include "DataFormats/JetReco/interface/PFJetCollection.h"
 #include "DataFormats/ParticleFlowCandidate/interface/PFCandidate.h"
 #include "DataFormats/Common/interface/ValueMap.h"
+#include "DataFormats/Math/interface/deltaPhi.h"
 
 #include "RecoJets/JetProducers/interface/QGTagger.h"
 #include "RecoJets/JetAlgorithms/interface/QGLikelihoodCalculator.h"
@@ -160,7 +161,7 @@ template <class jetClass> void QGTagger::calcVariables(const jetClass *jet, edm:
 	  
     if(usePart){
       float deta = part->eta() - jet->eta();
-      float dphi = 2*atan(tan(((part->phi()-jet->phi()))/2));           
+      float dphi = reco::deltaPhi(part->phi(), jet->phi());
       float partPt = part->pt(); 
       float weight = partPt*partPt;