diff -N InterpolatedHMatrixBuilder.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ InterpolatedHMatrixBuilder.java	6 Jun 2008 07:27:32 -0000	1.1
@@ -0,0 +1,135 @@

+/*
+ * InterpolatedHMatrixBuilder.java
+ *
+ * Created on June 5, 2008, 11:54 PM
+ *
+ * $Id: InterpolatedHMatrixBuilder.java,v 1.1 2008/06/06 07:27:32 ngraf Exp $
+ */
+
+package org.lcsim.recon.emid.hmatrix;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeMap;
+import org.lcsim.conditions.ConditionsManager;
+import org.lcsim.conditions.ConditionsManager.ConditionsNotFoundException;
+import org.lcsim.conditions.ConditionsManager.ConditionsSetNotFoundException;
+import org.lcsim.conditions.ConditionsSet;
+import org.lcsim.math.interpolation.BilinearInterpolator;
+
+/**
+ * This class uses data stored in a properties file to create an InterpolatedHMatrix
+ * which is able to calculate a cluster "chi-squared" for arbitrary values of theta and 
+ * energy
+ *
+ * @author Norman Graf
+ */
+public class InterpolatedHMatrixBuilder
+{
+    static final boolean debug = false;
+    
+    /**
+     * Given a detectorname, this method will locate the appropriate
+     * properties file and create an HMatrix which interpolates between 
+     * the discrete points in theta and energy.
+     *
+     * @param detectorName the name of a supported detector
+     * @return an InterpolatedHMatrix
+     */
+    public static InterpolatedHMatrix build(String detectorName)
+    {
+        String conditionsSetName = detectorName+"_HMatrices";
+        ConditionsManager mgr = ConditionsManager.defaultInstance();
+        try
+        {
+            mgr.setDetector(detectorName, 0);
+        }
+        catch( ConditionsNotFoundException e)
+        {
+            System.out.println("Conditions not found for detector "+mgr.getDetector());
+            System.out.println("Please check that this properties file exists for this detector ");
+            throw new RuntimeException("Conditions not found for detector "+mgr.getDetector());
+        }
+        ConditionsSet cs = null;
+        try
+        {
+            cs = mgr.getConditions(conditionsSetName);
+        }
+        catch(ConditionsSetNotFoundException e)
+        {
+            System.out.println("ConditionSet "+conditionsSetName+" not found for detector "+mgr.getDetector());
+            System.out.println("Please check that this properties file exists for this detector ");
+            throw new RuntimeException("ConditionSet "+conditionsSetName+" not found for detector "+mgr.getDetector());
+            
+        }
+        
+        int dim = cs.getInt("Dimensionality");
+        double[] energies = cs.getDoubleArray("EnergyVals");
+        int numEnergies = energies.length;
+        if(debug) System.out.println("energies: "+Arrays.toString(energies));
+        double[] angles = cs.getDoubleArray("ThetaVals");
+        int numAngles = angles.length;
+        if(debug) System.out.println("angles: "+Arrays.toString(angles));
+        
+        // Maps to hold all the arrays of numbers keyed on theta and energy
+        Map<String, double[]> avMap = new TreeMap<String, double[]>();
+        Map<String, double[]> covMap = new HashMap<String, double[]>();
+        
+        for(double theta : angles)
+        {
+            for( double energy : energies)
+            {
+                String key = "Theta_"+theta+"_Energy_"+energy;
+                avMap.put(key, cs.getDoubleArray(key+"_vals"));
+                covMap.put(key, cs.getDoubleArray(key+"_covs"));
+                if(debug) System.out.println(key);
+            }
+        }
+        
+        // for each theta and energy point, we have:
+        // n           average values
+        // n*(n+1)/2   covariance values (packed)
+        //
+        // will need to create a bilinearInterpolator for each of these (n^2+3n)/2 parameters
+        
+        // order is theta, energy
+        double[][] tmp = new double[numAngles][numEnergies];
+        BilinearInterpolator[] valInterpolators = new BilinearInterpolator[dim];
+        
+        // mean vector [dim]
+        for (int iVal=0; iVal<dim; ++iVal)
+        {
+            for(int i=0; i<numAngles; ++i)
+            {
+                for(int j=0; j<numEnergies; ++j)
+                {
+                    String key = "Theta_"+angles[i]+"_Energy_"+energies[j];
+                    tmp[i][j] = avMap.get(key)[iVal];
+                    if(debug) System.out.println(key +"_"+iVal+" "+  tmp[i][j]);
+                }
+            }
+            valInterpolators[iVal] = new BilinearInterpolator(angles, energies, tmp);
+        }
+        
+        // cov matrix elements [(dim*(dim+1))/2]
+        int covDim = (dim*(dim+1))/2;
+        BilinearInterpolator[] covInterpolators = new BilinearInterpolator[(dim*(dim+1))/2];
+        
+        for (int iVal=0; iVal<covDim; ++iVal)
+        {
+            for(int i=0; i<numAngles; ++i)
+            {
+                for(int j=0; j<numEnergies; ++j)
+                {
+                    String key = "Theta_"+angles[i]+"_Energy_"+energies[j];
+                    tmp[i][j] = covMap.get(key)[iVal];
+                    if(debug) System.out.println(key +"_"+iVal+" "+  tmp[i][j]);
+                }
+            }
+            covInterpolators[iVal] = new BilinearInterpolator(angles, energies, tmp);
+        }
+        
+        return new InterpolatedHMatrix(dim, valInterpolators, covInterpolators);
+    }
+}

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