original_function_point_set.java

Genetic Programming。GP算法在方程逼近求解上的应用。

import java.io.*;
public class Original_Function_Point_Set {

  static final int MAX_NR_OF_FITNESS_CASES = 100;

  private String rawText;
  public RealPoint[] data;
  public Original_Function_Point_Set( String rawText) {
            super();


            this.rawText = rawText;
            this.data = read(rawText);

	}

  public RealPoint[] get() {
              return data;
	}
  public static RealPoint[] read(String s) {
          StringBufferInputStream stream = new StringBufferInputStream(s);
          StreamTokenizer tokenizer = new StreamTokenizer(stream);
          RealPoint[] temp = new RealPoint[MAX_NR_OF_FITNESS_CASES];
          int count = 0;
          try {
                  int token;
                  do {
                          double x;
                          double y;
                          token = tokenizer.nextToken();
                          if (token == StreamTokenizer.TT_NUMBER) {
                                  x = tokenizer.nval;
                                  token =	tokenizer.nextToken();
                                  if (token	== StreamTokenizer.TT_NUMBER) {
                                          y = tokenizer.nval;
                                          temp[count] = new RealPoint(x, y);
                                          count++;
                                  }
                          }
                  } while (count < MAX_NR_OF_FITNESS_CASES && token != StreamTokenizer.TT_EOF);
          } catch (Exception e) {
                  ;
          }
          RealPoint[] result = new RealPoint[count];
          System.arraycopy(temp, 0, result, 0, count);
          return result;
	}
public static String makeDefaultFitnessCases(int number) {
        int NrOfFitnessCases = 20;
        String s=null;
        switch(number)
         {
         	case 0: {s="// 3*x^4 - 3*x + 1\n";break;}
         	case 1: {s="//sin(x)\n";break;}
         	case 2: {s="//cos(x)\n";break;}
         }
        
        for (int i = 0; i < NrOfFitnessCases; i++) {
                double x = (double)i / (NrOfFitnessCases - 1);
                if (x == 0.0) {
                        x = 1.0e-7;
                }
         double y = 0;
         
         switch(number)
         {
         case 0:
         {y=1.0 + (-3.0)*x + (3.0)*x*x*x*x;break;}
         case 1:
         {y=Math.sin(x);break;}
         case 2:
         {y=Math.cos(x);break;}
                
          }
               //	The stream tokenizer does not handle numbers with an exponent.
                //	Therefore, clamp small numbers like 1.2e-6 to 0:
                if (Math.abs(x) < 1.0e-5) {
                        x = 0;
                };
                if (Math.abs(y) < 1.0e-5) {
                        y = 0;
                };
                s = s + x + "  " + y + "\n";
        }
        return s;
        }

}