diff -N CalorimeterHitDSort.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ CalorimeterHitDSort.java	6 Oct 2010 19:53:35 -0000	1.1
@@ -0,0 +1,23 @@

+package org.lcsim.recon.cluster.util;
+
+import java.util.Comparator;
+import java.util.*;
+import hep.physics.vec.*;
+import org.lcsim.event.CalorimeterHit;
+
+/**
+ * A comparator useful for sorting hits according to hit energies.
+ *
+ * Usage:   Collections.sort( aHitCollection, new CalorimeterHitESort() );
+ *
+ * @author Guilherme Lima
+ * @version $Id: CalorimeterHitDSort.java,v 1.1 2010/10/06 19:53:35 cassell Exp $
+ */
+public class CalorimeterHitDSort implements Comparator<CalorimeterHit>
+{
+    public int compare(CalorimeterHit x1, CalorimeterHit x2)
+    {
+        if( new BasicHep3Vector(x1.getPosition()).magnitudeSquared() - new BasicHep3Vector(x2.getPosition()).magnitudeSquared() > 0 ) return 1;
+        return -1;
+    }
+}