人工鱼群算法java版

这是自己在图像分割时用到的，稍作修改变成简单的求解二元二次函数问题，没有进行优化，确定可以

    (1)    步长和视野为定值，可以修改为变值，先大后小

(2)    每次探路后的迈步也可以进行优化，此处未用

(3)    对于不需要的部分完全可以剪枝

(4) 可以增加变化机制，适当微量调整最优值

一、主函数

package AFAS_PACK;import java.io.IOException;public class mainTest {/** * @param args * @throws IOException * @author sun  */public static void main(String[] args) throws IOException {//int fishNum, int tryTime, int dim, double step, double delta, double visualSystem.out.println("begin");AFAS run = new AFAS(10,5,2,5,0.2,10);  run.doAFAS(40 );//括号内为迭代次数}}

二、人工鱼

package AFAS_PACK;import java.io.IOException;public class Fish {public int dim;                   //每条鱼的维度public int[] x;                //每条鱼的具体多维坐标public double fit;                //鱼的适应值，浓度public int visaul;             //每条鱼的视野public final double[] H = new double[256];public final double[] W = new double[256];public Fish(int dim, int visaul) throws IOException {super();this.dim = dim;this.visaul = visaul;x = new int[dim];for(int i=0;i<dim;i++)x[i] = (int) Math.floor(256*Math.random());fit = 0;//init();}/*getfit = newfunction(this.x[0],this.x[1]);*/public double distance(Fish f){double a = 0;for(int i=0;i<dim;i++){if(this.x[i]-f.x[i]==0)a = 0.00001;else a += (this.x[i]-f.x[i])*(this.x[i]-f.x[i]);}return Math.sqrt(a);}public  double newfunction(int[] w) throws IOException {          return -(w[0]*w[0]-160*w[0]+640+w[1]*w[1]-260*w[1]+16900);}}

三、AFAS算法部分

package AFAS_PACK;import java.io.IOException;import java.util.Date;public class AFAS {//鱼群数目private int fishNum;//尝试次数private int tryTime;//维度private int dim;//人工鱼移动步长private int step;//拥挤度因子private double delta;//视野范围private int visual;//人工鱼群、范围内最佳鱼，遍历时的下一条鱼Fish[] fish;Fish bestfish;Fish[] nextfish;//遍历索引int index;double[][] vector;private int[] choosed;//范围内鱼群数目 fishCountpublic int scopelength;public AFAS(){}public AFAS(int fishNum, int tryTime, int dim, int step, double delta, int visual) throws IOException {super();this.fishNum = fishNum;this.tryTime = tryTime;this.dim = dim;this.step = step;this.delta = delta;this.visual = visual;fish = new Fish[fishNum];nextfish = new Fish[3];vector = new double[fishNum][dim];choosed = new int[fishNum];index = 0;init();}public void doAFAS(int num) throws IOException {  long startTime = new Date().getTime();double a = 0.0;int count = 1;             //计算查找次数int len = 0;while(count<=num){     for(int i=0; i<fishNum; i++)     {     prey(i);         swarm(i);         follow(i);         bulletin(i);         System.out.println("第"+count+"遍第"+i+"条鱼结束");     }         System.out.println(count+"当前最优值："+bestfish.fit); for(int i=0; i<dim; i++) { System.out.print("位置"+(i+1)+":  "+bestfish.x[i]);   } System.out.println(); count++; System.out.println("step:"+step+"    visaul:"+visual);}System.out.println("最优值："+bestfish.fit);for(int i=0; i<dim; i++){    System.out.print("位置"+(i+1)+":  "+bestfish.x[i]);  }long endTime = new Date().getTime();System.out.println("本程序运行计时： "+(endTime-startTime)+" 毫秒。");}private void bulletin(int i) throws IOException {Fish maxfish = new Fish(dim,visual);maxfish = nextfish[0];for(int j=0;j<3;j++){if(nextfish[j].fit>maxfish.fit && nextfish[j].x[0]!=0 && nextfish[j].x[1]!=0){maxfish = nextfish[j];}}if(maxfish.fit<fish[i].fit){return ;}fish[i] = maxfish;if(maxfish.fit>bestfish.fit)bestfish = maxfish;}private void follow(int i) throws IOException {nextfish[2] = new Fish(dim,visual);Fish minfish = new Fish(dim,visual);                    // 中心位置minfish = fish[i];Fish[] scope = getScopefish(i);int key = i;if(scope!=null){for(int j=0;j<scope.length;j++){if(scope[j].fit<minfish.fit){minfish = scope[j];key = j;}}if(minfish.fit>=fish[i].fit)prey(i);else{Fish[] newScope = getScopefish(key);if(newScope!=null){if(newScope.length*minfish.fit<delta*fish[i].fit){double dis = fish[i].distance(minfish);for(int k=0;k<dim;k++){nextfish[2].x[k] = (int) (fish[i].x[k]+(minfish.x[k]-fish[i].x[k])*step*Math.random()/dis);}nextfish[2].fit = nextfish[2].newfunction(nextfish[2].x);}else prey(i);}else prey(i);}}else prey(i);}private void swarm(int i) throws IOException {                               //swam  startnextfish[1] = new Fish(dim,visual);int[] center = new int[dim];                    // 中心位置for(int j=0;j<dim;j++)center[j] = 0;Fish[] scope = getScopefish(i);if(scope!=null){for(int j=0;j<scope.length;j++)                     // 计算人工鱼的中心位置{for( i=0; i<dim; ++i )center[i] += scope[j].x[i];}for( i=0; i<dim; i++ )center[i] /= scope.length;                               // 人工鱼的中心位置//满足条件double dis=0.0;Fish centerfish = new Fish(dim,visual);centerfish.x = center;centerfish.fit = centerfish.newfunction(centerfish.x);dis = fish[i].distance(centerfish);if(centerfish.fit>fish[i].fit && scope.length*centerfish.fit<delta*fish[i].fit){for(int j=0;j<dim;j++){nextfish[1].x[j] = (int) (fish[i].x[j]+(centerfish.x[j]-fish[i].x[j])*step*Math.random()/dis);}nextfish[1].fit = nextfish[1].newfunction(nextfish[1].x);}else  prey(i); }else  prey(i); }                                               //swam  endprivate void prey(int i) throws IOException  {                      //prey startFish newfish = new Fish(dim,visual);newfish.fit = 0;nextfish[0] = new Fish(dim,visual);for(int k=0; k<tryTime; k++ )           // 进行try_number次尝试{for(int j=0; j<dim; j++ ){newfish.x[j] = (int) ((2*(Math.random())-1)*visual);}newfish.fit = newfish.newfunction(newfish.x);if( newfish.fit > fish[i].fit ){double dis = fish[i].distance(newfish);for(int j=0; j<dim; j++ ){nextfish[0].x[j] = (int) (fish[i].x[j]+(newfish.x[j]-fish[i].x[j])*step*Math.random()/dis);}nextfish[0].fit =nextfish[0].newfunction(nextfish[0].x); }else{for(int j=0; j<dim; j++){nextfish[0].x[j] = (int) (fish[i].x[j]+visual*(2*(Math.random())-1));nextfish[0].fit = nextfish[0].newfunction(nextfish[0].x);}}}}private Fish[] getScopefish(int i) {int num = 0;for(int j=0;j<fishNum;j++){choosed[j] = -1;if(fish[i].distance(fish[j])<visual){choosed[j] = i;num++;}}if(num!=0){Fish[] scope = new Fish[num];int k = 0;for(int j=0;j<fishNum;j++){if(choosed[j]!=-1)scope[k++] = fish[choosed[j]];}return scope;}return null;}                                                    //prey  endprivate void init() throws IOException {for(int i=0;i<fishNum;i++){fish[i] = new Fish(dim,visual);fish[i].fit = fish[i].newfunction(fish[i].x);}bestfish = new Fish(dim,visual);bestfish.fit = -999999;}}