From 2bd7e5ae175c67f6b39f48196e940bc679237980 Mon Sep 17 00:00:00 2001
From: mmusich <marco.musich@cern.ch>
Date: Mon, 7 Aug 2023 12:25:04 +0200
Subject: [PATCH] SiStripClusters2ApproxClusters: run peakFilter only if
 cluster is usable

---
 .../plugins/SiStripClusters2ApproxClusters.cc | 38 +++++++++++--------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/RecoLocalTracker/SiStripClusterizer/plugins/SiStripClusters2ApproxClusters.cc b/RecoLocalTracker/SiStripClusterizer/plugins/SiStripClusters2ApproxClusters.cc
index c842c384c4971..fd9a784fcb5a8 100644
--- a/RecoLocalTracker/SiStripClusterizer/plugins/SiStripClusters2ApproxClusters.cc
+++ b/RecoLocalTracker/SiStripClusterizer/plugins/SiStripClusters2ApproxClusters.cc
@@ -126,22 +126,28 @@ void SiStripClusters2ApproxClusters::produce(edm::Event& event, edm::EventSetup
 
       int hitStrips;
       float hitPredPos;
-      theFilter->getSizes(detId, cluster, lp, ldir, hitStrips, hitPredPos);
-
-      bool peakFilter = false;
-      SlidingPeakFinder pf(std::max<int>(2, std::ceil(std::abs(hitPredPos) + subclusterWindow_)));
-      float mipnorm = mip / std::abs(ldir.z());
-      PeakFinderTest test(mipnorm,
-                          detId,
-                          cluster.firstStrip(),
-                          theNoise_,
-                          seedCutMIPs_,
-                          seedCutSN_,
-                          subclusterCutMIPs_,
-                          subclusterCutSN_);
-      peakFilter = pf.apply(cluster.amplitudes(), test);
-
-      ff.push_back(SiStripApproximateCluster(cluster, maxNSat, hitPredPos, peakFilter));
+      bool usable = theFilter->getSizes(detId, cluster, lp, ldir, hitStrips, hitPredPos);
+      // (almost) same logic as in StripSubClusterShapeTrajectoryFilter
+      bool isTrivial = (std::abs(hitPredPos) < 2.f && hitStrips <= 2);
+
+      if (!usable || isTrivial) {
+        ff.push_back(SiStripApproximateCluster(cluster, maxNSat, hitPredPos, true));
+      } else {
+        bool peakFilter = false;
+        SlidingPeakFinder pf(std::max<int>(2, std::ceil(std::abs(hitPredPos) + subclusterWindow_)));
+        float mipnorm = mip / std::abs(ldir.z());
+        PeakFinderTest test(mipnorm,
+                            detId,
+                            cluster.firstStrip(),
+                            theNoise_,
+                            seedCutMIPs_,
+                            seedCutSN_,
+                            subclusterCutMIPs_,
+                            subclusterCutSN_);
+        peakFilter = pf.apply(cluster.amplitudes(), test);
+
+        ff.push_back(SiStripApproximateCluster(cluster, maxNSat, hitPredPos, peakFilter));
+      }
     }
   }