--- java/trunk/hps-java/src/main/java/org/lcsim/hps/recon/ecal/EcalClustererCosmics.java	                        (rev 0)
+++ java/trunk/hps-java/src/main/java/org/lcsim/hps/recon/ecal/EcalClustererCosmics.java	2014-01-28 20:22:22 UTC (rev 120)
@@ -0,0 +1,174 @@

+package org.lcsim.hps.recon.ecal;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.lcsim.event.CalorimeterHit;
+import org.lcsim.event.EventHeader;
+import org.lcsim.geometry.Detector;
+import org.lcsim.geometry.subdetector.HPSEcal3.NeighborMap;
+import org.lcsim.geometry.subdetector.HPSEcal3;
+import org.lcsim.util.Driver;
+import org.lcsim.lcio.LCIOConstants;
+
+/**
+ * This Driver creates clusters from the CalorimeterHits of an
+ * {@link org.lcsim.geometry.subdetectur.HPSEcal3} detector.
+ *
+ * The clustering algorithm is from pages 83 and 84 of the HPS Proposal.
+ *
+ * @author Jeremy McCormick <[log in to unmask]>
+ * @author Tim Nelson <[log in to unmask]>
+ *
+ * @version $Id: EcalClusterer.java,v 1.1 2013/02/25 22:39:24 meeg Exp $
+ */
+public class EcalClustererCosmics extends Driver {
+
+    HPSEcal3 ecal;
+    String ecalCollectionName;
+    String ecalName = "Ecal";
+    String clusterCollectionName = "EcalClusters";
+    // Minimum E for cluster seed.
+    double seedEMin = .05 * ECalUtils.GeV;
+    // Minimum E to add hit to cluster.
+    double addEMin = .03 * ECalUtils.GeV;
+    // Odd or even number of crystals in X.
+    boolean oddX;
+    // Map of crystals to their neighbors.
+    NeighborMap neighborMap = null;
+
+    public EcalClustererCosmics() {
+    }
+
+    public void setClusterCollectionName(String clusterCollectionName) {
+        this.clusterCollectionName = clusterCollectionName;
+    }
+
+    public void setSeedEMin(double seedEMin) {
+        this.seedEMin = seedEMin;
+    }
+
+    public void setAddEMin(double addEMin) {
+        this.addEMin = addEMin;
+        if (seedEMin < addEMin) {
+            seedEMin = addEMin;
+        }
+    }
+
+    public void setEcalCollectionName(String ecalCollectionName) {
+        this.ecalCollectionName = ecalCollectionName;
+    }
+
+    public void setEcalName(String ecalName) {
+        this.ecalName = ecalName;
+    }
+
+    public void startOfData() {
+        if (ecalCollectionName == null) {
+            throw new RuntimeException("The parameter ecalCollectionName was not set!");
+        }
+
+        if (ecalName == null) {
+            throw new RuntimeException("The parameter ecalName was not set!");
+        }
+    }
+
+    public void detectorChanged(Detector detector) {
+        // Get the Subdetector.
+        ecal = (HPSEcal3) detector.getSubdetector(ecalName);
+
+        // Cache ref to neighbor map.
+        neighborMap = ecal.getNeighborMap();
+
+        //System.out.println(ecal.getName());
+        //System.out.println("  nx="+ecal.nx());
+        //System.out.println("  ny="+ecal.ny());
+        //System.out.println("  beamgap="+ecal.beamGap());
+        //System.out.println("  dface="+ecal.distanceToFace());
+
+        //System.out.println(neighborMap.toString());
+    }
+
+    public void process(EventHeader event) {
+        //System.out.println(this.getClass().getCanonicalName() + " - process");
+
+        if (event.hasCollection(CalorimeterHit.class, ecalCollectionName)) {
+            // Get the list of raw ECal hits.
+            List<CalorimeterHit> hits = event.get(CalorimeterHit.class, ecalCollectionName);
+
+            // Make a hit map for quick lookup by ID.
+            Map<Long, CalorimeterHit> hitMap = new HashMap<Long, CalorimeterHit>();
+            
+            System.out.println("Number of ECal hits: "+hitMap.size());
+            
+            for (CalorimeterHit hit : hits) {
+                hitMap.put(hit.getCellID(), hit);
+            }
+
+            // Put Cluster collection into event.
+            int flag = 1 << LCIOConstants.CLBIT_HITS;
+            event.put(clusterCollectionName, createClusters(hitMap), HPSEcalCluster.class, flag);
+        }
+    }
+
+    public List<HPSEcalCluster> createClusters(Map<Long, CalorimeterHit> map) {
+
+        // New Cluster list to be added to event.
+        List<HPSEcalCluster> clusters = new ArrayList<HPSEcalCluster>();
+
+        // Loop over ECal hits to find cluster seeds.
+        for (CalorimeterHit hit : map.values()) {
+            // Cut on min seed E.
+            if (hit.getRawEnergy() < seedEMin) {
+                continue;
+            }
+
+            // Get neighbor crystal IDs.
+            Set<Long> neighbors = neighborMap.get(hit.getCellID());
+
+            if (neighbors == null) {
+                throw new RuntimeException("Oops!  Set of neighbors is null!");
+            }
+
+            // List for neighboring hits.
+            List<CalorimeterHit> neighborHits = new ArrayList<CalorimeterHit>();
+
+            // Loop over neighbors to make hit list for cluster.
+            boolean isSeed = true;
+            for (Long neighborId : neighbors) {
+                // Find the neighbor hit in the event if it exists.
+                CalorimeterHit neighborHit = map.get(neighborId);
+
+                // Was this neighbor cell hit?
+                if (neighborHit != null) {
+                    // Check if neighbor cell has more energy.
+                    if (neighborHit.getRawEnergy() > hit.getRawEnergy()) {
+                        // Neighbor has more energy, so cell is not a seed.
+                        isSeed = false;
+                        break;
+                    }
+
+                    // Add to cluster if above min E.
+                    if (neighborHit.getRawEnergy() >= addEMin) {
+                        neighborHits.add(neighborHit);
+                    }
+                }
+            }
+
+            // Did we find a seed?
+            if (isSeed) {
+                // Make a cluster from the hit list.
+                HPSEcalCluster cluster = new HPSEcalCluster(hit);
+                cluster.addHit(hit);
+                for (CalorimeterHit clusHit : neighborHits) {
+                    cluster.addHit(clusHit);
+                }
+                clusters.add(cluster);
+            }
+        }
+        return clusters;
+    }
+}

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