diff -u -r1.3 -r1.4
--- LocalHelixExtrapolator.java	20 Jun 2008 18:53:10 -0000	1.3
+++ LocalHelixExtrapolator.java	20 Jun 2008 18:59:02 -0000	1.4
@@ -347,6 +347,26 @@

 	}
     }
 

+    public Long extendToHCALLayerAndFindCell(int layer) {
+	Hep3Vector point = extendToHCALLayer(layer);
+	IDDecoder id = null;
+	if (m_barrelValid) {
+	    id = m_event.getDetector().getDecoder("HcalBarrHits");
+	    if (id == null) { throw new AssertionError("Failed to find barrel ID"); }
+	} else if (m_endcapValid) {
+	    id = m_event.getDetector().getDecoder("HcalEndcapHits");
+	    if (id == null) { throw new AssertionError("Failed to find endcap ID"); }
+	}
+	if (id != null) {
+	    long cell = id.findCellContainingXYZ(point);
+	    id.setID(cell);
+	    Hep3Vector cellCenter = id.getPositionVector();
+	    return new Long(cell);
+	} else {
+	    return null;
+	}
+    }
+

     /** Assumes extrapolation has already been done. */
     public Hep3Vector getTangent() {
 	double dphi = 0.01;