diff -u -r1.1 -r1.2
--- PerfectClusterer.java	22 Jun 2006 01:18:55 -0000	1.1
+++ PerfectClusterer.java	4 Jul 2006 23:47:54 -0000	1.2
@@ -2,6 +2,7 @@

 
 import java.util.*;
 

+import org.lcsim.util.hitmap.HitMap;

 import org.lcsim.event.EventHeader;
 import org.lcsim.util.Driver;
 import org.lcsim.event.Cluster;

@@ -13,7 +14,7 @@

 /**
  * A clusterer with perfect pattern recognition
  *

- * @version $Id: PerfectClusterer.java,v 1.1 2006/06/22 01:18:55 mcharles Exp $

+ * @version $Id: PerfectClusterer.java,v 1.2 2006/07/04 23:47:54 mcharles Exp $

  */
 
 public class PerfectClusterer extends Driver

@@ -28,13 +29,18 @@

      * Process one event, separating the input hits into
      * clusters as perfectly as possible based on the
      * MC truth list.

+     *
+     * Optionally, clusters may share a hit if more than one
+     * particle contributed to it.
+     *
+     * @version $Id: PerfectClusterer.java,v 1.2 2006/07/04 23:47:54 mcharles Exp $

      */
     public void process(EventHeader event) 
     {
 	List<MCParticle> mcList = event.get(MCParticle.class, m_mcName);

-	Map<Long, CalorimeterHit> inputHitMap = (Map<Long, CalorimeterHit>) (event.get(m_inputHitMapName));

+	HitMap inputHitMap = (HitMap) (event.get(m_inputHitMapName));

-	Map<Long, CalorimeterHit> outputHitMap = new HashMap<Long, CalorimeterHit>(inputHitMap); // initially cloned

+	HitMap outputHitMap = new HitMap(inputHitMap); // initially cloned

 	Collection<CalorimeterHit> hits = inputHitMap.values(); // initially full
 	Map<MCParticle, BasicCluster> particleToClusterMap = new HashMap<MCParticle, BasicCluster>(); // initially empty
 	

@@ -44,6 +50,21 @@

 	    //   (1) More than one particle deposits energy in the cell
 	    //   (2) The list of MC particles is ambiguous
 	    Set<MCParticle> truthParticles = findMCParticles(hit, mcList);

+	    if (!m_allowHitSharing) {
+		// We disallow hit sharing => only take the particle with
+		// the biggest contribution.
+		MCParticle biggestContributor = null;
+		double biggestContribution = 0.0;
+		for (MCParticle part : truthParticles) {
+		    double contribution = findContributionByMCParticle(hit, mcList, part);
+		    if (contribution > biggestContribution || biggestContributor == null) {
+			biggestContributor = part;
+			biggestContribution = contribution;
+		    }
+		}
+		truthParticles = new HashSet<MCParticle>();
+		truthParticles.add(biggestContributor);
+	    }

 	    for (MCParticle part : truthParticles) {
 		BasicCluster clus = particleToClusterMap.get(part);
 		if (clus == null) {

@@ -154,9 +175,14 @@

     public void setMCParticleList(String name) {
 	m_mcName = name;
     }

-    

+    /** Set whether or not hits may be shared among clusters. */
+    public void allowHitSharing(boolean allow) {
+	m_allowHitSharing = allow;
+    }
+

     String m_inputHitMapName;
     String m_outputHitMapName;
     String m_outputClusterListName;
     String m_mcName;

+    boolean m_allowHitSharing = true;

 }