Palpha.java

/*
 * Class:        Palpha
 * Description:  computes the P_alpha figure of merit for a lattice
 * Environment:  Java
 * Software:     SSJ 
 * Copyright (C) 2001  Pierre L'Ecuyer and Universite de Montreal
 * Organization: DIRO, Universite de Montreal
 * @author       Richard Simard
 * @since        January 2009
 
 * SSJ is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License (GPL) as published by the
 * Free Software Foundation, either version 3 of the License, or
 * any later version.
 
 * SSJ is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 
 * A copy of the GNU General Public License is available at
   <a href="http://www.gnu.org/licenses">GPL licence site</a>.
 */
package umontreal.ssj.discrepancy;
 
import umontreal.ssj.hups.Rank1Lattice;
import umontreal.ssj.util.Num;
import umontreal.ssj.util.PrintfFormat;

public class Palpha extends Discrepancy {
   // J'utilise les gamma de la classe mère pour beta[]
   private double[] C; // beta * factors
   private int alpha;
 
   private void initFactor(int s, double[] Beta, int alpha) {
      C = new double[s];
      for (int j = 1; j <= s; j++)
         C[j - 1] = Math.pow(2.0 * Math.PI * Beta[j], (double) alpha) / Num.factorial(alpha);
   }
 
   private void initA(int s, double[] bet, int alp) {
      if (null == bet) {
         setONES(s);
         gamma = ONES;
      } else
         gamma = bet;
      alpha = alp;
   }

   public Palpha(double[][] points, int n, int s, double[] beta, int alpha) {
      super(points, n, s, beta);
      initA(s, beta, alpha);
   }

   public Palpha(double[][] points, int n, int s, int alpha) {
      super(points, n, s);
      initA(s, null, alpha);
   }

   public Palpha(int n, int s, double[] beta, int alpha) {
      super(n, s, beta);
      initA(s, beta, alpha);
   }

   public Palpha(int alpha) {
      this.alpha = alpha;
   }

   public Palpha(Rank1Lattice set, double[] beta, int alpha) {
      super(set);
      initA(set.getDimension(), beta, alpha);
   }

   public double compute(double[][] points, int n, int s) {
      return compute(points, n, s, null, alpha);
   }

   public double compute(double[][] points, int n, int s, double[] beta) {
      return compute(points, n, s, beta, alpha);
   }

   public double compute(double[][] points, int n, int s, int alpha) {
      return compute(points, n, s, null, alpha);
   }

   public double compute(double[][] points, int n, int s, double[] beta, int alpha) {
      initA(s, beta, alpha);
      initFactor(s, gamma, alpha);
 
      switch (alpha) {
      case 2:
         return calcPalpha2(points, n, s, gamma);
      case 4:
         return calcPalpha4(points, n, s, gamma);
      case 6:
         return calcPalpha6(points, n, s, gamma);
      case 8:
         return calcPalpha8(points, n, s, gamma);
      default:
         throw new IllegalArgumentException("alpha must be one of {2, 4, 6, 8}");
      }
   }

   private double calcPalpha2(double[][] points, int N, int s, double[] beta) {
      double sum = 0.0;
      for (int i = 0; i < N; ++i) {
         double prod = 1.0;
         for (int j = 0; j < s; ++j) {
            double u = Points[i][j];
            prod *= 1.0 + C[j] * (u * (u - 1.0) + UNSIX);
         }
         sum += prod;
      }
      sum /= N;
      return beta[0] * (sum - 1.0);
   }

   private double calcPalpha4(double[][] points, int N, int s, double[] beta) {
      double sum = 0.0;
      for (int i = 0; i < N; ++i) {
         double prod = 1.0;
         for (int j = 0; j < s; ++j) {
            double u = Points[i][j];
            prod *= 1.0 - C[j] * (((u - 2.0) * u + 1.0) * u * u - UNTRENTE);
         }
         sum += prod;
      }
      sum /= N;
      return beta[0] * (sum - 1.0);
   }

   private double calcPalpha6(double[][] points, int N, int s, double[] beta) {
      double sum = 0.0;
      for (int i = 0; i < N; ++i) {
         double prod = 1.0;
         for (int j = 0; j < s; ++j) {
            double u = Points[i][j];
            prod *= 1.0 + C[j] * ((((u - 3.0) * u + 2.5) * u * u - 0.5) * u * u + QUARAN);
         }
         sum += prod;
      }
      sum /= N;
      return beta[0] * (sum - 1.0);
   }

   private double calcPalpha8(double[][] points, int N, int s, double[] beta) {
      double sum = 0.0;
      for (int i = 0; i < N; ++i) {
         double prod = 1.0;
         for (int j = 0; j < s; ++j) {
            double u = Points[i][j];
            prod *= 1.0 - C[j] * (((((u - 4.0) * u + QTIERS) * u * u - STIERS) * u * u + DTIERS) * u * u - UNTRENTE);
         }
         sum += prod;
      }
      sum /= N;
      return beta[0] * (sum - 1.0);
   }
 
   public String toString() {
      StringBuffer sb = new StringBuffer(getName() + ":" + PrintfFormat.NEWLINE);
      sb.append("n = " + numPoints + ",   dim = " + dim + PrintfFormat.NEWLINE);
      sb.append("gamma = [");
      appendGamma(sb, gamma, dim + 1);
      sb.append(" ]" + PrintfFormat.NEWLINE);
      sb.append("alpha = " + alpha + PrintfFormat.NEWLINE);
      return sb.toString();
   }

   public void setBeta(double[] beta) {
      gamma = beta;
   }
 
}