lcsim/src/org/lcsim/util/swim

diff -u -r1.28 -r1.29
--- Helix.java	10 Feb 2010 21:57:30 -0000	1.28
+++ Helix.java	8 Mar 2010 12:13:39 -0000	1.29
@@ -25,7 +25,7 @@

  * by Paul Avery.
  * 
  * @author tonyj

- * @version $Id: Helix.java,v 1.28 2010/02/10 21:57:30 partridge Exp $

+ * @version $Id: Helix.java,v 1.29 2010/03/08 12:13:39 cassell Exp $

  */
 public class Helix implements Trajectory {
     /**

@@ -138,9 +138,11 @@

         //  Calculate how far we are from the desired point
         Hep3Vector delta = VecOp.sub(pos, point);
 

+        int count = 0;
+        int maxcount = 20;

         //  Iteratively close in on the point of closest approach
         while (delta.magnitude() > eps) {

-            

+            count++;

             //  Calculate the coefficients of the indicial equations a*s^2 + b*s + c = 0
             double c = VecOp.dot(u, delta);
             double b = 1. - rho * VecOp.dot(VecOp.cross(u, zhat), delta);

@@ -164,15 +166,16 @@

                 u = unew;
                 pos = pos1;
                 stot += s1;

-                if (Math.abs(s1) < eps/100.) return stot;

+                if (Math.abs(s1) < eps) return stot;

             } else {
                 unew = propagateDirection(u, s2);
                 u = unew;
                 pos = pos2;
                 stot += s2;

-                if (Math.abs(s2) < eps/100.) return stot;

+                if (Math.abs(s2) < eps) return stot;

             }
 

+            if(count > maxcount)return stot;

             //  Update how far we are from the specified point
             delta = VecOp.sub(pos, point);
         }

@@ -381,4 +384,5 @@

 
     //  Set the desired precision in finding the point closest to the track
     private double eps = 1.e-6;  //  1 nm ought to be good enough for government work!

+    public void setExtrapToPointPrecision(double prec){eps = prec;}

 }