diff -u -r1.4 -r1.5
--- HPSEcal.java	13 Apr 2011 20:06:42 -0000	1.4
+++ HPSEcal.java	13 Apr 2011 21:58:24 -0000	1.5
@@ -24,12 +24,13 @@

  * The layout element defines the placement of the crystals.  The beamgap defines the
  * offset from the beamline in the Y coordinate, in the natural Geant4 coordinate system.
  * The nx attribute defines the number of crystals in the X coordinate.  The ny attribute

- * defines the number of crystals in Y, on each side of the beamline.

+ * defines the number of crystals in Y, on each side of the beamline.  For example, to 
+ * get 4 rows of crystals in Y, then ny would be 2.

  * 
  * @author Jeremy McCormick
  * @author Tim Nelson
  * 

- * @version $Id: HPSEcal.java,v 1.4 2011/04/13 20:06:42 jeremy Exp $

+ * @version $Id: HPSEcal.java,v 1.5 2011/04/13 21:58:24 jeremy Exp $

  */
 public class HPSEcal extends LCDDSubdetector
 {

@@ -37,10 +38,7 @@

     {
         super(node); 
     }

-
-    /* (non-Javadoc)
-     * @see org.lcsim.geometry.compact.converter.lcdd.LCDDSubdetector#addToLCDD(org.lcsim.geometry.compact.converter.lcdd.util.LCDD, org.lcsim.geometry.compact.converter.lcdd.util.SensitiveDetector)
-     */

+    

     void addToLCDD(LCDD lcdd, SensitiveDetector sens) throws JDOMException
     {
         // Get the half-dimensions of the calorimeter crystal.

@@ -63,7 +61,7 @@

         Element layout = node.getChild("layout");
         double beamgap = layout.getAttribute("beamgap").getDoubleValue();
         int nx = layout.getAttribute("nx").getIntValue();

-        int ny = layout.getAttribute("ny").getIntValue();

+        int ny = layout.getAttribute("ny").getIntValue();       

         
         System.out.println("beamgap="+beamgap);
         System.out.println("nx="+nx);

@@ -79,16 +77,25 @@

         Volume mother = lcdd.pickMotherVolume(this);
         
         // Slope of the trapezoid side in X.

-        double s = (dx2-dx1)/(2*dz);

+        double sx = (dx2-dx1)/(2*dz);

         
         // Angle of the side of the trapezoid w.r.t. center line in X.  Rotation about Y axis.

-        double dthetay = atan(s);        

+        double dthetay = atan(sx);        
+        
+        // Slope of the trapezoid side in Y.
+        double sy = (dy2-dy1)/(2*dz);      
+        
+        // Angle of the side of the trapezoid w.r.t. center line in Y.  Rotation about X axis.        
+        double dthetax = atan(sx);

-        // Distance between (virtual) angular origin and center of trapezoid.
-        double z0 = dx1/s+dz;

+        // Distance between (virtual) angular origin and center of trapezoid in X.
+        double z0x = dx1/sx+dz;
+        
+        // // Distance between (virtual) angular origin and center of trapezoid in Y.
+        double z0y = dy1/sy+dz;

         
         // Always 0. (no rotation about Z)

-        double thetaz = 0;

+        //double thetaz = 0;

         
         // Odd or even number of crystals in X.
         boolean oddx = (nx % 2 != 0);

@@ -103,77 +110,85 @@

         {
             nx /= 2;
         }

-        
-        double thetax = 0;
-        double ycenter = 0;
-        double zcorrtot = 0;
-        double xcorrtot = 0;
-                        

+
+        double ycorrtot = 0;
+        double zcorrtoty = 0;

         //double fudgeFactor = .01;

-        
-        for (int ix=0; ix<=nx; ix++)

+
+        for (int iy=1; iy<=ny; iy++)

         {

-            System.out.println("ix="+ix);
-            
-            // Factor for even/odd.
-            int coeff = 2*ix;
-            if (!oddx)
-            {
-                coeff -= 1;
-                if (ix==0)
-                    continue;
-            }
-            
-            System.out.println("coffee="+coeff);
-            
-            double thetay = coeff*dthetay;
-            double zcorr = dx1*(2*sin(coeff*dthetay));
-            // Center point of trap front face along line instead of edge.
-            // double zcorr = dx1*(sin(2*ix*dthetay))+sin(2*(ix-1)*dthetay));            
-            double xcorr = zcorr*tan((coeff-1)*dthetay);
-            //+ fudgeFactor;
-            double xcenter = z0*sin(coeff*dthetay)+xcorr+xcorrtot;
-            double zcenter = z0*(cos(coeff*dthetay)-1)+zcorr+zcorrtot;
-                        
-            System.out.println("xcorr="+xcorr);
-            System.out.println("xcorrtot="+xcorrtot);
-            System.out.println("xcenter="+xcenter);
-            System.out.println("zcenter="+zcenter);
-            System.out.println("zcorr="+zcorr);
-            System.out.println("zcorrtot="+zcorrtot);
-            System.out.println("thetay="+thetay);
-            System.out.println();

+            double zcorrtotx = 0;
+            double xcorrtot = 0;

-            Position ipos = 
-                new Position("crystal"+ix+"_pos_pos", xcenter, ycenter, zcenter);
-            Rotation irot = 
-                new Rotation("crystal"+ix+"_rot_pos", thetax, -thetay, thetaz);
-            
-            define.addPosition(ipos);
-            define.addRotation(irot);            
-                
-            // Place crystal.
-            PhysVol posCrystalPlacement = new PhysVol(crystalLogVol, mother, ipos, irot);
-            // TODO Add PhysVolID.
-            
-            // Reflection to negative.
-            if (ix != 0)
-            {
-                Position iposneg = 
-                    new Position("crystal"+ix+"_pos_neg", -xcenter, ycenter, zcenter);
-                Rotation irotneg =                 
-                    new Rotation("crystal"+ix+"_rot_neg", thetax, thetay, thetaz);

+            int coeffy = 2*iy-1;
+            double thetax = coeffy*dthetax;
+            double zcorry = dy1*(2*sin(coeffy*dthetax));
+            double ycorr = zcorry*tan((coeffy-1)*dthetax);
+            double ycenter = z0y*sin(coeffy*dthetax)+ycorr+ycorrtot;
+            
+            for (int ix=0; ix<=nx; ix++)
+            {                             
+                // Factor for even/odd.
+                int coeffx = 2*ix;
+                if (!oddx)
+                {
+                    coeffx -= 1;
+                    if (ix==0)
+                        continue;
+                }

-                define.addPosition(iposneg);
-                define.addRotation(irotneg);

+                double thetay = coeffx*dthetay;
+                double zcorrx = dx1*(2*sin(coeffx*dthetay));
+                // Center point of trap front face along line instead of edge.
+                // double zcorr = dx1*(sin(2*ix*dthetay))+sin(2*(ix-1)*dthetay));            
+                double xcorr = zcorrx*tan((coeffx-1)*dthetay);
+                //+ fudgeFactor;
+                double xcenter = z0x*sin(coeffx*dthetay)+xcorr+xcorrtot;
+                double zcenter = z0y*(cos(coeffy*dthetax)-1)+z0x*(cos(coeffx*dthetay)-1)+zcorrx+zcorrtotx+zcorry+zcorrtoty;
+
+                //double thetaz = -Math.pow(sin(thetay),2)*thetax;
+                double thetaz = 0;
+                                
+                String baseName = "crystal"+ix+"-"+iy;

-                PhysVol negCrystalPlacement = new PhysVol(crystalLogVol, mother, iposneg, irotneg);

+                // TEST
+                //if (iy == ny)
+                //{                                   
+                Position ipos = 
+                    new Position(baseName+"_pos_pos", xcenter, ycenter, zcenter);
+                Rotation irot = 
+                    new Rotation(baseName+"_rot_pos", thetax, -thetay, thetaz);
+
+                define.addPosition(ipos);
+                define.addRotation(irot);            
+
+                // Place crystal.
+                PhysVol posCrystalPlacement = new PhysVol(crystalLogVol, mother, ipos, irot);

                 // TODO Add PhysVolID.

-            }
-            
-            // Increment running X and Z totals.
-            xcorrtot += xcorr;
-            zcorrtot += zcorr;
-        }