遗传算法的C语言程序案例

1、共享知识分享快乐卑微如蜷蚁、坚以大象盛年不重来，一日难再晨。及时宜自勉，岁月不待人遗传算法的C语言程序案例一、说明1 本程序演示的是用简单遗传算法随机一个种群，然后根据所给的交叉率，变异率，世代 数计算最大适应度所在的代数2 演示程序以用户和计算机的对话方式执行，即在计算机终端上显示“提示信息”之后， 由用户在键盘上输入演示程序中规定的命令；相应的输入数据和运算结果显示在其后。3举个例子，输入初始变量后，用 y= (x1*x1)+(x2*x2)，其中-2.048=x1,x2=2.048作适应度 函数求最大适应度即为函数的最大值4 程序流程图开始Gen=O5 类型定义int popsize;/

2、种群大小共享知识分享快乐卑微如蜷蚁粵虽似大象int maxgeneration;/ 最大世代数double pc;/ 交叉率double pm;/ 变异率struct in dividualchar chromchromle ngth+1;double value;double fitness;/ 适应度;int gen erati on;/ 世代数int best_ in dex;int worstndex;struct in dividual besti ndividual; / 最佳个体struct in dividual worsti ndividual; / 最差个体struct i

3、n dividual curre ntbest;struct in dividual populatio nPOPSIZE;3 函数声明void gen erate in itialpopulati on();void gen erate nextpopulati on();void evaluatepopulati on();long decodechromosome(char *,i nt,i nt);void calculateobjectvalue();void calculatefit nessvalue();void fin dbesta ndworsti ndividual();

4、void performevoluti on();void selectoperator();void crossoveroperator();void mutati ono perator();void in put();void outputtextreport();6 程序的各函数的简单算法说明如下：(1) void gen eratei ni tialpopulatio n ()和 void in put ()初始化种群和遗传算法参数。input()函数输入种群大小，染色体长度，最大世代数，交叉率，变异率等参数。(2)void calculateobjectvalue();计算适应度函

5、数值。根据给定的变量用适应度函数计算然后返回适度值。(3) 选择函数 selectoperator()在函数selectoperator()中首先用rand ()函数产生01间的选择算子，当适度累计值不为零共享知识分享快乐卑微如蜷蚁、粵雖大象时，比较各个体所占总的适应度百分比的累计和与选择算子，直到达到选择算子的值那个个体就被选出，即适应度为fi的个体以fi/刀的概率继续存在；显然，个体适应度愈高，被选中的概率愈大。但是，适应度小的个体也有可能被选中，以便增加下一代群体的多样性。(4 )染色体交叉函数 crossoveroperator()这是遗传算法中的最重要的函数之一，它是对个体两个变量所

6、合成的染色体进行交叉，而不是变量染色体的交叉，这要搞清楚。首先用rand ()函数产生随机概率，若小于交叉概率，则进行染色体交叉，同时交叉次数加1。这时又要用rand()函数随机产生一位交叉位，把染色体的交叉位的后面部分交叉即可；若大于交叉概率，则进行简单的染色体复制即可。(5 )染色体变异函数mutatio n()变异是针对染色体字符变异的，而不是对个体而言，即个体变异的概率是一样。随机产生比较概率，若小于变异概率，则1变为0, 0变为1，同时变异次数加1。(6) long decodechromosome(char *,int,int)本函数是染色体解码函数，它将以数组形式存储的二进制数转

7、成十进制数，然后才能用适应度函数计算。(7) void findbestandworstindividual()本函数是求最大适应度个体的，每一代的所有个体都 要和初始的最佳比较，如果大于就赋给最佳。(8) void outputtextreport () 输出种群统计结果输出每一代的种群的最大适应度和平均适应度，最后输出全局最大值二、运行环境本程序的开发工具是VC+,在VC+下运行。源代码#i ncludestdafx.h#i nclude |#in clude #in clude /The definiton of user data 定义用户数据 Illi#defi ne Cmax 10

8、0 /certa in maximal value #define Cmin 0 /certain minimum value#defi ne LENGHT1 3#defi ne LENGHT2 3/总染体长度#defi ne CHROMLENGTH LENGHT1+LENGHT2const int MaxGe nerati on = 100;const int PopSize = 10;const double Pc = 0.6;con st double Pm = 0.001;/ 数据结构定义 /struct In dividualchar chromCHROMLENGTH + 1;dou

9、ble value;double fitn ess;共享知识分享快乐皋微如蜷蚁、粵虽似大象； int gen erati on ;int bestI ndex;int worstI ndex;In dividual bestI ndividual ;In dividual worst In dividual ;/ best in dividual by nowIn dividual curre ntBest ;In dividual populati on PopSize;/ void gen erate In itialPopulati on();void gen erateNextPopu

10、lati on();void evalutePopulati on();long decomdeChromosome(char*, in t, i nt);void calculateObjectValue();void calculateFit nessValue();void fin dBestA ndWorstl ndividual();void performEvoluti on();void select ionO perator();void crossoverOperator();void mutati onO perator();void outputTextReport();

11、/以上为函数以及全局变量定义部分 int mai n()gen erati on = 0;gen erate In itialPopulati on(); evalutePopulati on();while (ge nerati on MaxGe nerati on) gen erati on+;gen erateNextPopulati on(); evalutePopulati on(); performEvoluti on(); outputTextReport();system(pause);return 0;共享知识分享快乐皋微如蜷蚁坚以大象/IIIIII产生第一代样本/void

12、gen erate In itialPopulati on() int i, j;sran d( un sig ned)time(NULL);for (i = 0; i PopSize; i+) for (j = 0; j CHROMLENGTH; j+) populatio ni.chromj = (ra nd() % 10) 5) ? O : 1;populatio ni.chromCHROMLENGTH =70：/产生下一代样本/void gen erateNextPopulati on() select ionO perator(); |crossoverOperator();muta

13、ti onO perator();变异算子void mutati onO perator() int i, j;double p;/ bit mutati onfor (i = 0; i PopSize; i+) for (j = 0; j CHROMLENGTH; j+) p = ran d() % 1000 / 1000.0;if (p Pm) populatio ni.chromj = (populatio ni.chromj = 0) ? 1: 0; /交叉算子/void crossoverOperator() int i, j;int in dexPopSize;int point,

14、 temp;double p;共享知识分享快乐皋微如蜷蚁、粵雖大象char ch;for (i = 0; i PopSize; i+) in dexi = i;for (i = 0; i PopSize; i+) point = ran d() %(PopSize - i);temp = in dexi;in dexi = in dexpo int + i;in dexpo int + i = temp;for (i = 0; i PopSize - 1; i+=2) p = ran d() % 1000 / 1000.0;if (p Pc) point = rand()% (CHROMLEN

15、GTH - 1) + 1;for (j = poi nt; j CHROMLENGTH; j+) ch = populati on i ndexi.chromj;populati on i ndexi.chromj = populati on i ndexi + 1.chromj;populati on i ndexi + 1.chromj = ch;/选择算子 /void select ionO perator() in t i, i ndex;double p, sum = 0.0;double cfitn essPopSize;In dividual n ewpopulati on Po

16、pSize;for (i = 0; i PopSize; i+) sum += populatio ni.fit ness;for (i = 0; i PopSize; i+) cfitn essi = populati on i.fit ness / sum; / calculate cumulative fitn ess for (i = 1; i PopSize; i+) cfitn essi = cfitn essi + cfitn essi - 1; for (i = 0; i cfitn essi ndex) in dex+;n ewpopulati on i = populati

17、 on i ndex;for (i = 0; i PopSize; i+) populati on i = n ewpopulati on i; /共享知识分享快乐卑微如罐蛟、竖副欢象/依据某些公式对样本进行评价1111void evalutePopulati on() calculateObjectValue();calculateFit nessValue();fin dBestA ndWorstl ndividual(); / |/找出到目前为止最好的个体/void fin dBestA ndWorstl ndividual() int i;double sum = 0.0;bestI

18、ndividual = populati on 0;worstI ndividual = populati on 0;for (i = 0; i bestIndividual.fitness) bestI ndividual = populati on i;bestI ndex = i; else if (populationi.fitness curre ntBest.fit ness) curre ntBest = bestl ndividual; |计算适应度IIIvoid calculateFit nessValue() int i;long temp1, temp2; |double

19、 x1, x2; |for (i = 0; i PopSize; i+) temp1 = decomdeChromosome(populatio ni.chrom, 0, LENGHT1);temp2 = decomdeChromosome(populatio ni.chrom, LENGHT1, LENGHT2); x1 = temp1 * temp1;x2 = temp2 * temp2;populationi.fitness = x1+x2; x1平方加上 x2 平方共享知识分享快乐皋微如蜷蚁、粵雖大象/计算目标值 / 目标函数为 f(x) = x1* x1 + x2*x2 void calculateObjectValue() int i;long temp1, temp2; double x1, x2;for (i = 0; i PopSize; i+) temp1 = decomdeChromosome(populatio ni.chrom, 0, LENGHT1);temp2 = decomdeChromosome(populatio ni.chrom, LENGHT1, LENGHT2); x1 = temp1 * temp1;x2 = temp2 * temp2;populati