gaamutation.java

Java实现的遗传算法工具集：GA Playground

public class GaaMutation {
	
	int gaType;
	int mutationType;
	double mutationRate;
	GaaAllele alleles[];
	
	public GaaMutation (GaaProblem problem) {
		
		gaType = problem.gaType;
		mutationType = problem.mutationType;
		mutationRate = problem.mutationRate;
		alleles = problem.alleles;
		
	}


	public String mutation(String chrom) {
		
		return (mutation(chrom, mutationRate));
		
	}
	

	public String mutation(String chrom, double rate) {
		
		int i, j, size;
		char kar, kar2;
		double n;
		String st;
		StringBuffer sb = new StringBuffer(chrom);
		size = chrom.length();

		switch (gaType) {
			case 1:
				for (i=0;i<size;i++) {
					if (GaaMisc.flip(rate)) {
							n = alleles[i].min + (double) Math.random()*(alleles[i].max-alleles[i].min);
							kar = alleles[i].encodeValue(n);
							sb.setCharAt(i,kar);
					}
				}
				break;
			case 2:
				for (i=0;i<size;i++) {
					if (GaaMisc.flip(rate)) {
							j = (int) Math.floor(Math.random()*size);
							Integer int1 = new Integer(i);
							Integer int2 = new Integer(j);
							if (!int2.equals(int1)) {
								kar = sb.charAt(i);
								kar2 = sb.charAt(j);
								sb.setCharAt(i,kar2);
								sb.setCharAt(j,kar);
							}
					}
				}
				break;
		}

		st = sb.toString();
		return st;

	}		
	
		
}