--- java/trunk/ecal-readout-sim/src/main/java/org/hps/readout/ecal/FADCTriggerDriver.java	2014-04-08 01:02:43 UTC (rev 465)
+++ java/trunk/ecal-readout-sim/src/main/java/org/hps/readout/ecal/FADCTriggerDriver.java	2014-04-08 01:05:06 UTC (rev 466)
@@ -42,6 +42,7 @@

     private double energyDistanceThreshold = 0.5;
     // maximum time difference between two clusters, in units of readout cycles (4 ns).
     private int pairCoincidence = 2;

+    private double originX = 1393.0 * Math.tan(0.03052); //ECal midplane, defined by photon beam position (30.52 mrad) at ECal face (z=1393 mm)

     int allPairs;
     int oppositeQuadrantCount;
     int clusterEnergyCount;

@@ -126,6 +127,16 @@

         this.pairCoincidence = pairCoincidence;
     }
 

+    /**
+     * Set X coordinate used as the origin for cluster coplanarity and distance
+     * calculations. Defaults to the ECal midplane.
+     *
+     * @param originX
+     */
+    public void setOriginX(double originX) {
+        this.originX = originX;
+    }
+

     @Override
     public void detectorChanged(Detector detector) {
         setBeamEnergy(this.getBeamEnergyFromDetector(detector));

@@ -512,10 +523,10 @@

 
     protected double getClusterAngle(HPSEcalCluster cluster) { //returns angle in range of -180 to 180
         double position[] = cluster.getSeedHit().getPosition();

-        return Math.toDegrees(Math.atan2(position[1], position[0]));

+        return Math.toDegrees(Math.atan2(position[1], position[0] - originX));

     }
 
     protected double getClusterDistance(HPSEcalCluster cluster) {

-        return Math.hypot(cluster.getSeedHit().getPosition()[0], cluster.getSeedHit().getPosition()[1]);

+        return Math.hypot(cluster.getSeedHit().getPosition()[0] - originX, cluster.getSeedHit().getPosition()[1]);

     }
 }

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