Adjusting RecHit reco for edge wire groups

Adjusting RecHit reco for edge wire groups. Best improvement is obtained for the first and last wire group of ME11 station. For details see https://indico.cern.ch/event/968978/contributions/4078288/attachments/2133771/3594383/20_10_30-Voytishin_Palichik-CSC_rh_builder_improvement_updates.pdf

RecoLocalMuon/CSCRecHitD/src/CSCMake2DRecHit.cc

@@ -140,37 +140,48 @@ CSCRecHit2D CSCMake2DRecHit::hitFromStripAndWire(const CSCDetId& id,
   float sigmaWithinTheStrip = -99.;
   int quality = -1;
   LocalPoint lp0(0., 0.);
-
+  int wglo = wg_left;
+  int wghi = wg_right;
+
+  float ymiddle;
+
+  // First wire of first wiregroup in cluster
+  wglo = layergeom_->middleWireOfGroup(wglo) + 0.5 
+    - 0.5 * layergeom_->numberOfWiresPerGroup(wglo);
+
+  // Last wire in last wiregroup of cluster (OK if only 1 wiregroup too)
+  wghi = layergeom_->middleWireOfGroup(wghi) - 0.5 
+    + 0.5 * layergeom_->numberOfWiresPerGroup(wghi);
+
   float stripWidth = -99.f;
   // If at the edge, then used 1 strip cluster only
   if (centerStrip == 1 || centerStrip == specs_->nStrips() || nStrip < 2) {
-    lp0 = layergeom_->stripWireIntersection(centerStrip, centerWire);
+    lp0 = (layergeom_->possibleRecHitPosition( float(centerStrip) - 0.5, wilo, wihi )).first;
+    ymiddle = lp0.y();
     positionWithinTheStrip = 0.f;
     stripWidth = layergeom_->stripPitch(lp0);
     sigmaWithinTheStrip = stripWidth * inv_sqrt_12;
     quality = 2;
   } else {
     // If not at the edge, used cluster of size ClusterSize:
-    LocalPoint lp11 = layergeom_->stripWireIntersection(centerStrip, centerWire);
+    LocalPoint lp11 = (layergeom_->possibleRecHitPosition( float(centerStrip) - 0.5, wglo, wghi )).first;
+    ymiddle = lp11.y();
     stripWidth = layergeom_->stripPitch(lp11);
 
     //---- Calculate local position within the strip
     float xWithinChamber = lp11.x();
     quality = 0;
-    if (layergeom_->inside(lp11)) {  // save time; this hit is to be discarded anyway - see isHitInFiducial(...)
-
-      xMatchGatti_->findXOnStrip(id,
-                                 layer_,
-                                 sHit,
-                                 centerStrip,
-                                 xWithinChamber,
-                                 stripWidth,
-                                 tpeak,
-                                 positionWithinTheStrip,
-                                 sigmaWithinTheStrip,
-                                 quality);
-    }
-    lp0 = LocalPoint(xWithinChamber, layergeom_->yOfWire(centerWire, xWithinChamber));
+    xMatchGatti_->findXOnStrip(id,
+                               layer_,
+                               sHit,
+                               centerStrip,
+                               xWithinChamber,
+                               stripWidth,
+                               tpeak,
+                               positionWithinTheStrip,
+                               sigmaWithinTheStrip,
+                               quality);
+    lp0 = LocalPoint( xWithinChamber, ymiddle );
   }
 
   // compute the errors in local x and y