PartialVariance.java

package umontreal.ssj.mcqmctools.anova;
 
import umontreal.ssj.stat.Tally;

public class PartialVariance extends Tally implements Comparable<PartialVariance> {
 
   protected CoordinateSet coords;
   protected Tally totalVar;
 
   protected PartialVariance(CoordinateSet coords) {
      this(coords, null);
   }
 
   protected PartialVariance(CoordinateSet coords, Tally totalVar) {
      super("variance for coordinates " + coords);
      this.coords = coords;
      this.totalVar = totalVar;
   }

   public CoordinateSet getCoordinates() {
      return coords;
   }

   public double sensitivityIndex() {
 
      if (totalVar == null)
         throw new IllegalStateException(
               "trying to access the sensitivity index without" + " a reference to the total variance");
 
      return average() / totalVar.average();
   }

   public int compareTo(PartialVariance var) {
      double v = average();
      double vx = var.average();
      return v > vx ? 1 : v < vx ? -1 : 0;
   }
 
   @Override
   public String toString() {
 
      String s = String.format("%30s: %9.4g", coords.toString(), average());
 
      if (numberObs() > 1) {
         double dvar = Math.sqrt(variance() / numberObs());
         s += String.format(" ± %.2g", dvar);
      }
 
      if (totalVar != null) {
         double varFrac = sensitivityIndex();
         if (varFrac >= 0)
            s += String.format("  (%.4g %%)", 100 * varFrac);
      }
 
      return s;
   }
}