diff -u -r1.3 -r1.4
--- BilloirFitter.java	27 Mar 2006 21:45:27 -0000	1.3
+++ BilloirFitter.java	28 Mar 2006 01:15:24 -0000	1.4
@@ -1,7 +1,7 @@

 package org.lcsim.recon.vertexing.zvtop4.fitter;
 
 /**

- * @version $Id: BilloirFitter.java,v 1.3 2006/03/27 21:45:27 jstrube Exp $

+ * @version $Id: BilloirFitter.java,v 1.4 2006/03/28 01:15:24 jstrube Exp $

  */
 
 // Performs a Kalman fit to a list of tracks and returns

@@ -63,14 +63,16 @@

         }
         return pxfvtx(ntrk, withBeamConstraint, isInVtx, parameters, errors, initialPosition.getCartesianArray());
     }

-    

+    /**
+     * Conversion matrix from org.lcsim track parameters (old) to internal parameters
+     */

     private double[][] getJacobi(double[] old) {
         double[][] jacobi = new double[][]{
                  {old[0], 0, 0, 0, 0}
                , {0, 0, 0, old[1], 0}
                , {0, 0, 0, 0, old[2]}
                , {0, old[3], 0, 0, 0}

-               , {0, 0, 1+Math.tan(old[4])*Math.tan(old[4]), 0, 0}};

+               , {0, 0, -1-old[4]*old[4], 0, 0}};

         return jacobi;
     }