diff -N FieldTest.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ FieldTest.java	14 Sep 2007 23:01:54 -0000	1.1
@@ -0,0 +1,56 @@

+package org.lcsim.geometry.field;
+
+import hep.physics.vec.BasicHep3Vector;
+import hep.physics.vec.Hep3Vector;
+import junit.framework.*;
+import org.lcsim.geometry.FieldMap;
+
+/**
+ *
+ * @author tonyj
+ */
+public abstract class FieldTest extends TestCase
+{
+   public FieldTest(String testName)
+   {
+      super(testName);
+   }
+   
+   void testFieldAt(FieldMap map, double x, double y, double z, double bx, double by, double bz)
+   {
+      testFieldMethod1(map,x,y,z,bx,by,bz);
+      testFieldMethod2(map,x,y,z,bx,by,bz);
+      testFieldMethod3(map,x,y,z,bx,by,bz);
+      testFieldMethod4(map,x,y,z,bx,by,bz);                  
+   }
+   private void testFieldMethod1(FieldMap map, double x, double y, double z, double bx, double by, double bz)
+   {
+      double[] field = map.getField(new double[]{x,y,z});
+      assertEquals("Method 1, x",bx,field[0],1e-16);
+      assertEquals("Method 1, y",by,field[1],1e-16);
+      assertEquals("Method 1, z",bz,field[2],1e-16);
+   }
+   private void testFieldMethod2(FieldMap map, double x, double y, double z, double bx, double by, double bz)
+   {
+      Hep3Vector fieldVector = map.getField(new BasicHep3Vector(x,y,z));
+      assertEquals("Method 2, x",bx,fieldVector.x(),1e-16);
+      assertEquals("Method 2, y",by,fieldVector.y(),1e-16);
+      assertEquals("Method 2, z",bz,fieldVector.z(),1e-16); 
+   }
+   private void testFieldMethod3(FieldMap map, double x, double y, double z, double bx, double by, double bz)
+   {
+      double[] field = { 9,9,9 }; 
+      map.getField(new double[]{x,y,z},field);
+      assertEquals("Method 3, x",bx,field[0],1e-16);
+      assertEquals("Method 3, y",by,field[1],1e-16);
+      assertEquals("Method 3, z",bz,field[2],1e-16);
+   }
+   private void testFieldMethod4(FieldMap map, double x, double y, double z, double bx, double by, double bz)
+   {
+      BasicHep3Vector fieldVector = new BasicHep3Vector(9,9,9);
+      map.getField(new BasicHep3Vector(x,y,z),fieldVector);
+      assertEquals("Method 4, x",bx,fieldVector.x(),1e-16);
+      assertEquals("Method 4, y",by,fieldVector.y(),1e-16);
+      assertEquals("Method 4, z",bz,fieldVector.z(),1e-16); 
+   }
+}

diff -N SolenoidTest.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ SolenoidTest.java	14 Sep 2007 23:01:54 -0000	1.1
@@ -0,0 +1,38 @@

+package org.lcsim.geometry.field;
+
+import org.jdom.Element;
+import org.jdom.JDOMException;
+import org.lcsim.geometry.FieldMap;
+
+/**
+ *
+ * @author tonyj
+ */
+public class SolenoidTest extends FieldTest
+{
+   public SolenoidTest(String testName)
+   {
+      super(testName);
+   }
+   
+   FieldMap createMap() throws JDOMException
+   {
+      Element element = new Element("solenoid");
+      element.setAttribute("inner_field","5.0");
+      element.setAttribute("outer_field","-1.0");
+      element.setAttribute("zmax","100");
+      element.setAttribute("outer_radius","50");
+      return new Solenoid(element);
+   }
+   void checkMap(FieldMap map)
+   {
+      testFieldAt(map, 0,0,0,0,0,5);
+      testFieldAt(map, 40,40,0,0,0,-1);
+      testFieldAt(map, 0,0,-150,0,0,0);
+      testFieldAt(map, 40,40,-150,0,0,0);      
+   }
+   public void testSolenoid() throws JDOMException
+   {
+      checkMap(createMap());
+   }
+}

\ No newline at end of file

diff -N DipoleTest.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ DipoleTest.java	14 Sep 2007 23:01:54 -0000	1.1
@@ -0,0 +1,41 @@

+package org.lcsim.geometry.field;
+
+import org.jdom.Element;
+
+/**
+ *
+ * @author tonyj
+ */
+public class DipoleTest extends FieldTest
+{
+   private Dipole dipole;
+   public DipoleTest(String testName)
+   {
+      super(testName);
+   }
+   
+   protected void setUp() throws Exception
+   {
+      Element element = new Element("dipole");
+      element.setAttribute("zmin","10");
+      element.setAttribute("zmax","20");
+      element.setAttribute("rmax","100");
+      for (int i=0; i<3; i++)
+      {
+         Element coeff = new Element("dipoleCoeff");
+         coeff.setAttribute("value",String.valueOf(5-i));
+         element.addContent(coeff);
+      }
+      dipole = new Dipole(element);
+   }
+   
+   public void testDipole()
+   {
+      testFieldAt(dipole,0,0,0,0,0,0);
+      testFieldAt(dipole,0,0,40,0,0,0);
+      testFieldAt(dipole,80,80,15,0,0,0);
+      // FixMe: This is not correct 
+      testFieldAt(dipole,0,0,15,740,0,0);
+   }
+
+}

diff -u -r1.3 -r1.4
--- FieldOverlayTest.java	16 May 2007 23:27:38 -0000	1.3
+++ FieldOverlayTest.java	14 Sep 2007 23:01:54 -0000	1.4
@@ -1,9 +1,7 @@

 package org.lcsim.geometry.field;
 
 import java.io.InputStream;

-
-import junit.framework.TestCase;
-import junit.framework.TestSuite;

+import org.jdom.JDOMException;

 
 import org.lcsim.geometry.Detector;
 import org.lcsim.geometry.FieldMap;

@@ -13,21 +11,16 @@

  *
  * @author jeremym
  */

-public class FieldOverlayTest extends TestCase

+public class FieldOverlayTest extends FieldTest

 {

-    Detector det;

+    private Detector det;

 	
     /** Creates a new instance of FieldOverlayTest */
     public FieldOverlayTest(String name)
     {
         super(name);
     }

-    
-    public static junit.framework.Test suite()
-    {
-        return new TestSuite(FieldOverlayTest.class);
-    }
-    

+

     protected void setUp() throws Exception
     {
         InputStream in = 

@@ -39,10 +32,20 @@

     public void testFieldOverlay() throws Exception
     {
     	FieldMap field = det.getFieldMap();

-    	double[] p = {0,0,0};
-    	double[] v = field.getField(p);
-    	assertTrue(v[0] > 0.0);
-    	assertTrue(v[2] > 0.0);
-    	//System.out.println(v[0] + " " + v[1] + " " + v[2]);
-    }    

+        testFieldAt(field,0,0,0,1,0,5);
+    }   
+    
+    public void testEmptyOverlay()
+    {
+       FieldOverlay overlay = new FieldOverlay();
+       testFieldAt(overlay,0,0,0,0,0,0);
+    }
+    
+    public void testSingleOverlay() throws JDOMException
+    {
+       SolenoidTest test = new SolenoidTest("SolenoidTest");
+       FieldOverlay overlay = new FieldOverlay();
+       overlay.addField(test.createMap());
+       test.checkMap(overlay);
+    }

 }

\ No newline at end of file

diff -u -r1.1 -r1.2
--- RZFieldMapTest.java	1 Sep 2005 22:33:59 -0000	1.1
+++ RZFieldMapTest.java	14 Sep 2007 23:01:54 -0000	1.2
@@ -1,40 +1,28 @@

-/*
- * RZFieldMapTest.java
- *
- * Created on September 1, 2005, 1:57 PM
- *
- */
-

 package org.lcsim.geometry.field;
 
 import java.io.InputStream;

-import junit.framework.TestCase;
-import junit.framework.TestSuite;

 import org.lcsim.geometry.Detector;

+import org.lcsim.geometry.FieldMap;

 import org.lcsim.geometry.GeometryReader;
 
 /**
  *
  * @author jeremym
  */

-public class RZFieldMapTest extends TestCase

+public class RZFieldMapTest extends FieldTest

 {

-    

     /** Creates a new instance of RZFieldMapTest */
     public RZFieldMapTest(String name)
     {
         super(name);
     }

-    
-    public static junit.framework.Test suite()
-    {
-        return new TestSuite(RZFieldMapTest.class);
-    }
-    

+       

     public void testRead() throws Exception
     {
         InputStream in = this.getClass().getResourceAsStream("/org/lcsim/geometry/field/RZFieldMapTest.xml");        
         GeometryReader reader = new GeometryReader();
         Detector det = reader.read(in);

+        FieldMap map = det.getFieldMap();
+        testFieldAt(map,0,0,0,0,0,5.0011);

     }    
 }

\ No newline at end of file

diff -u -r1.5 -r1.6
--- FieldMap.java	11 May 2007 00:21:09 -0000	1.5
+++ FieldMap.java	14 Sep 2007 23:01:54 -0000	1.6
@@ -11,14 +11,14 @@

 {
    /** Get the field magnitude and direction at a particular point.
     * @param position The position at which the field is requested

-    * @param b The field (the object is passed by reference and updated)

+    * @param b The field (the object is passed by reference and set to the correct field)

     */
    public void getField(double[] position, double[] b);
    
    /**
     * Get the field magnitude and direction at a particular point. This method
     * requires allocation of a new object on each call, and should therefore not

-    * be used if it we be called many times.

+    * be used if it may be called many times.

     * @param position The position at which the field is requested
     * @return The field.
     * @deprecated @use getField(double[], double[])

@@ -28,7 +28,7 @@

    /**
     * Get the field magnitude and direction at a particular point.
     * @param position The position at which the field is requested.

-    * @param field The field. If not <code>null</code> this is passed by reference and updated

+    * @param field The field. If not <code>null</code> this is passed by reference and set to the correct field

     * @return The field. This will be the same object passed as field, unless field was <code>null</code>
     */
    public Hep3Vector getField(Hep3Vector position, BasicHep3Vector field);

diff -N AbstractFieldMap.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ AbstractFieldMap.java	14 Sep 2007 23:01:54 -0000	1.1
@@ -0,0 +1,50 @@

+package org.lcsim.geometry.field;
+
+import hep.physics.vec.BasicHep3Vector;
+import hep.physics.vec.Hep3Vector;
+import org.jdom.Element;
+import org.lcsim.geometry.FieldMap;
+import org.lcsim.geometry.compact.Field;
+
+/**
+ * Base class for field map implementations. Subclasses should override
+ * getXField, getYField, getZField as appropriate (the default implementation
+ * returns 0).
+ * @author tonyj
+ */
+abstract class AbstractFieldMap extends Field implements FieldMap
+{
+   AbstractFieldMap(Element node)
+   {
+      super(node);
+   }
+   abstract void getField(double x, double y, double z, BasicHep3Vector field);
+   
+   public Hep3Vector getField(Hep3Vector position, BasicHep3Vector field)
+   {
+      if (field == null) field = new BasicHep3Vector();
+      getField(position.x(),position.y(),position.z(),field);
+      return field;
+   }
+   
+   public Hep3Vector getField(Hep3Vector position)
+   {
+      return getField(position,null);
+   }
+   
+   public void getField(double[] position, double[] b)
+   {
+      BasicHep3Vector field = new BasicHep3Vector();
+      getField(position[0],position[1],position[2],field);
+      b[0] = field.x();
+      b[1] = field.y();
+      b[2] = field.z();
+   }
+   
+   public double[] getField(double[] position)
+   {
+      BasicHep3Vector field = new BasicHep3Vector();
+      getField(position[0],position[1],position[2],field);
+      return field.v();
+   }
+}

diff -u -r1.6 -r1.7
--- Solenoid.java	9 Apr 2007 05:04:29 -0000	1.6
+++ Solenoid.java	14 Sep 2007 23:01:54 -0000	1.7
@@ -1,24 +1,20 @@

 package org.lcsim.geometry.field;
 
 import hep.physics.vec.BasicHep3Vector;

-import hep.physics.vec.Hep3Vector;

 import org.jdom.Element;
 import org.jdom.JDOMException;

-import org.lcsim.geometry.FieldMap;
-import org.lcsim.geometry.compact.Field;

 
 /**

- * Solenoidal magentic field.

+ * Solenoidal magnetic field.

  * @author tonyj
  */
 

-public class Solenoid extends Field implements FieldMap

+public class Solenoid extends AbstractFieldMap

 {
    private double[] innerField;
    private double[] outerField;
    private double zmax;

-   private double outerRadius2;
-   //private double[] noField = { 0, 0, 0 };

+   private double outerRadiusSquared;

 
    Solenoid(Element node) throws JDOMException
    {

@@ -30,23 +26,18 @@

       outerField = new double[] { 0, 0, o};
       zmax = node.getAttribute("zmax").getDoubleValue();
       double r = node.getAttribute("outer_radius").getDoubleValue();

-      outerRadius2 = r*r;

+      outerRadiusSquared = r*r;

    }
 

-   public void getField(double[] position, double[] b)

+   void getField(double x, double y, double z, BasicHep3Vector field)

    {

-      if (Math.abs(position[2])>zmax) return;
-      double r2 = position[0]*position[0] + position[1]*position[1];
-      if (r2 > outerRadius2) b[2] += outerField[2];
-      else b[2] += innerField[2];
-   }
-   
-   // @deprecated
-   public double[] getField(double[] pos)
-   {
-   	double[] b = new double[3];
-   	getField(pos, b);
-   	return b;

+      if (Math.abs(z)>zmax) field.setV(0,0,0);
+      else
+      {
+         double r2 = x*x + y*y;
+         double bz = (r2 > outerRadiusSquared) ? outerField[2] : innerField[2];
+         field.setV(0,0,bz);
+      }

    }
 
    public double[] getInnerField()

@@ -66,18 +57,6 @@

 
    public double getOuterRadius2()
    {

-       return outerRadius2;
-   }
-
-   public Hep3Vector getField(Hep3Vector position, BasicHep3Vector field)
-   {
-      if (field == null) field = new BasicHep3Vector();
-      getField(position.v(),field.v());
-      return field;
-   }
-
-   public Hep3Vector getField(Hep3Vector position)
-   {
-      return getField(position,null);

+       return outerRadiusSquared;

    }
 }

\ No newline at end of file

diff -u -r1.3 -r1.4
--- FieldOverlay.java	9 Apr 2007 05:04:29 -0000	1.3
+++ FieldOverlay.java	14 Sep 2007 23:01:54 -0000	1.4
@@ -30,19 +30,26 @@

       fields.add(field);
    }
    

-   /**
-    * @param pos An array of size 3 containing the position.
-    * @param b An array of size 3 that is updated by this method to
-    * contain the Bfield components (bx,by,bz) of the overlay at pos.
-    */

    public void getField(double[] pos, double[] b)
    {

-      b[0] = b[1] = b[2] = 0.;
-      double[] temp = new double[3];
-      for (FieldMap field : fields)

+      int size = fields.size();
+      if (size == 0)

       {

-         field.getField(pos, temp);
-         for (int i=0; i<3; i++) b[i] += temp[i];

+         b[0] = b[1] = b[2] = 0.;
+      }
+      else if (size == 1)
+      {
+         fields.get(0).getField(pos,b);
+      }
+      else
+      {
+         double[] temp = new double[3];
+         b[0] = b[1] = b[2] = 0.;
+         for (FieldMap field : fields)
+         {
+            field.getField(pos, temp);
+            for (int i=0; i<3; i++) b[i] += temp[i];
+         }

       }
    }
    

@@ -56,13 +63,35 @@

    public Hep3Vector getField(Hep3Vector position, BasicHep3Vector field)
    {
       if (field == null) field = new BasicHep3Vector();

-      getField(position.v(),field.v());

+      int size = fields.size();
+      if (size == 0)
+      {
+         field.setV(0,0,0);
+      }
+      else if (size == 1)
+      {
+         fields.get(0).getField(position,field);
+      }
+      else
+      {
+         double bx = 0;
+         double by = 0;
+         double bz = 0;
+         BasicHep3Vector temp = new BasicHep3Vector();
+         for (FieldMap map : fields)
+         {
+            map.getField(position,temp);
+            bx += temp.x();
+            by += temp.y();
+            bz += temp.z();
+         }
+         field.setV(bx,by,bz);
+      }

       return field;
    }

-

+   

    public Hep3Vector getField(Hep3Vector position)
    {
       return getField(position,null);
    }

-   

 }

\ No newline at end of file

diff -u -r1.2 -r1.3
--- Dipole.java	9 Apr 2007 05:04:29 -0000	1.2
+++ Dipole.java	14 Sep 2007 23:01:54 -0000	1.3
@@ -1,21 +1,16 @@

 package org.lcsim.geometry.field;
 
 import hep.physics.vec.BasicHep3Vector;

-import hep.physics.vec.Hep3Vector;
-import static java.lang.Math.pow;
-import static java.lang.Math.sqrt;
-

+import java.util.List;

 import org.jdom.Element;
 import org.jdom.JDOMException;

-import org.lcsim.geometry.FieldMap;
-import org.lcsim.geometry.compact.Field;

-public class Dipole extends Field implements FieldMap

+public class Dipole extends AbstractFieldMap

 {
    private double[] coeffs;
    private double zmin;
    private double zmax;

-   private double rmax;

+   private double rSquaredMax;

    
    public Dipole(Element node) throws JDOMException
    {

@@ -23,57 +18,34 @@

       
       zmin = node.getAttribute("zmin").getDoubleValue();
       zmax = node.getAttribute("zmax").getDoubleValue();

-      rmax = node.getAttribute("rmax").getDoubleValue();

+      double rmax = node.getAttribute("rmax").getDoubleValue();
+      rSquaredMax = rmax*rmax;

       
       int ncoeff = node.getChildren("dipoleCoeff").size();
       coeffs = new double[ncoeff];
       
       int i = 0;

-      for (Object o : node.getChildren("dipoleCoeff"))

+      for (Element e : (List<Element>) node.getChildren("dipoleCoeff"))

       {

-         Element e = (Element) o;
-         double coeff = e.getAttribute("value").getDoubleValue();
-         coeffs[i] = coeff;
-         ++i;

+         coeffs[i++] = e.getAttribute("value").getDoubleValue();

       }
    }

-   
-   public void getField(double[] position, double[] b)

+   void getField(double x, double y, double z, BasicHep3Vector field)

    {
       double bx = 0;

-      double z = position[2];
-      double r = sqrt(position[0] * position[0] + position[1] * position[1]);

+      double rSquared = x*x + y*y;
+      double zPowerI = 1;

       
       // Check if z coordinate is within dipole z bounds.

-      if (z > zmin && z < zmax && r < rmax)

+      if (z > zmin && z < zmax && rSquared < rSquaredMax)

       {
          // Apply all coefficients to this z coordinate.
          for (int i = 0; i < coeffs.length; ++i)
          {

-            bx += coeffs[i] * pow(z, i);

+            bx += coeffs[i] * zPowerI;
+            zPowerI *= z;

          }

-         
-         // Apply Bx to input array.
-         b[0] += bx;

       }

-   }
-   
-   public double[] getField(double[] p)
-   {
-      double[] b = new double[3];
-      getField(p, b);
-      return b;
-   }
-   
-   public Hep3Vector getField(Hep3Vector position, BasicHep3Vector field)
-   {
-      if (field == null) field = new BasicHep3Vector();
-      getField(position.v(),field.v());
-      return field;
-   }
-
-   public Hep3Vector getField(Hep3Vector position)
-   {
-      return getField(position,null);

+      field.setV(bx,0,0);

    }
 }

\ No newline at end of file