GPU: Use average eta estimate for initial ZOffset during track seeding

davidrohr · davidrohr · commit 8d47a855bd9a · 2023-01-18T10:39:48.000+01:00
diff --git a/GPU/GPUTracking/Definitions/GPUSettingsList.h b/GPU/GPUTracking/Definitions/GPUSettingsList.h
@@ -48,6 +48,7 @@ AddOptionRTC(zsThreshold, float, 2.0f, "", 0, "Zero-Suppression threshold")
 AddOptionRTC(tubeChi2, float, 5.f * 5.f, "", 0, "Max chi2 to mark cluster adjacent to track")
 AddOptionRTC(tubeMaxSize2, float, 2.5f * 2.5f, "", 0, "Square of max tube size (normally derrived from tpcTubeChi2)")
 AddOptionRTC(clustersShiftTimebins, float, 0, "", 0, "Shift of TPC clusters (applied during CTF cluster decoding)")
+AddOptionRTC(defaultZOffsetOverR, float, 0.5210953f, "", 0, "Shift of TPC clusters (applied during CTF cluster decoding)")
 AddOptionRTC(maxTimeBinAboveThresholdIn1000Bin, unsigned short, 500, "", 0, "Except pad from cluster finding if total number of charges in a fragment is above this baseline (disable = 0)")
 AddOptionRTC(maxConsecTimeBinAboveThreshold, unsigned short, 200, "", 0, "Except pad from cluster finding if number of consecutive charges in a fragment is above this baseline (disable = 0)")
 AddOptionRTC(noisyPadSaturationThreshold, unsigned short, 700, "", 0, "Threshold where a timebin is considered saturated, disabling the noisy pad check for that pad")
diff --git a/GPU/GPUTracking/SliceTracker/GPUTPCTrackletConstructor.cxx b/GPU/GPUTracking/SliceTracker/GPUTPCTrackletConstructor.cxx
@@ -140,9 +140,10 @@ GPUdic(2, 1) void GPUTPCTrackletConstructor::UpdateTracklet(int /*nBlocks*/, int
         tParam.SetY(y);
         r.mLastY = y;
         if (tracker.Param().par.continuousTracking) {
-          tParam.SetZ(0.f);
-          r.mLastZ = 0.f;
-          tParam.SetZOffset(z);
+          float refZ = ((z > 0) ? tracker.Param().rec.tpc.defaultZOffsetOverR : -tracker.Param().rec.tpc.defaultZOffsetOverR) * x;
+          tParam.SetZ(refZ);
+          r.mLastZ = refZ;
+          tParam.SetZOffset(z - refZ);
         } else {
           tParam.SetZ(z);
           r.mLastZ = z;
