遗传算法源代码

#include
#include
#include

#define POPSIZE 500
#define MAXIMIZATION 1
#define MINIMIZATION 2
#define Cmax 100
#define Cmin 0
#define LENGTH1 10
#define LENGTH2 10
#define CHROMLENGTH LENGTH1+LENGTH2
int FunctionMode=MAXIMIZATION;
int PopSize =80;
int MaxGeneration =200;
double Pc = 0.6;
double Pm = 0.001;
struct individual
{
char chrom[CHROMLENGTH+1];
double value;
double fitness;
};
int generation;
int best_index;
int worst_index;
struct individual bestindividual;
struct individual worstindividual;
struct individual currentbest;
struct individual population[POPSIZE];
void GenerateInitialPopulation(void);
void GenerateNextPopulation(void);

void EvaluatePopulation(void);
void CalculateObjectValue(void);
long DecodeChromosome(char *,int,int);

void CalculateFitnessValue(void);
void FindBestAndWorstIndividual(void);
void PerformEvolution(void);
void SelectionOperator(void);

void CrossoverOperator(void);
void MutationOperator(void);

void OutputTextReport(void);
void main(void)
{
generation=0;
GenerateInitialPopulation();

EvaluatePopulation();
while(generation{
generation++;
GenerateNextPopulation();
EvaluatePopulation();
PerformEvolution();
OutputTextReport();
}
}

void GenerateInitialPopulation(void )
{
int i,j;
for (i=0;i{
for(j=0;j{
population[i].chrom[j]=(rand()%10<5)?'0':'1';
}

population[i].chrom[CHROMLENGTH]='\0';

}
}




void GenerateNextPopulation(void)
{
SelectionOperator();
CrossoverOperator();
MutationOperator();
}

void EvaluatePopulation()
{
CalculateObjectValue();
CalculateFitnessValue();
FindBestAndWorstIndividual();
}
long DecodeChromosome(char *string,int point,int length)
{
int i;
long decimal=0L;
char *pointer;
for(i=0,pointer=string+point;i{
decimal+=(*pointer-'0')<<(length-1-i);
}
return(decimal);
}
void CalculateObjectValue(void)
{
int i;
long temp1,temp2;
double x1,x2;
for (i=0;i{
temp1=DecodeChromosome(population[i].chrom,0,LENGTH1);
temp2=DecodeChromosome(population[i].chrom,LENGTH1,LENGTH2);
x1=4.096*temp1/1023.0-2.048;
x2=4.096*temp2/1023.0-2.048;
population[i].value=100*(x1*x1-x2)*(x1*x1-x2)+(1-x1)*(1-x1);
}
}
void CalculateFitnessValue(void)
{
int i;
double temp;
for (i=0;i{
if (FunctionMode==MAXIMIZATION)
{
if((population[i].value+Cmin)>0.0)
{
temp=Cmin+population[i].value;
}
else
{
temp=0.0;
}


}
else if(FunctionMode==MINIMIZATION)
{
if(population[i].value{
temp=Cmax-population[i].value;
}
else
{
temp=0.0;
}
}

population[i].fitness=temp;
}
}
void FindBestAndWorstIndividual(void )
{
int i;
doub

le sum=0.0;

bestindividual=population[0];
worstindividual=population[0];
for (i=1;i{
if (population[i].fitness>bestindividual.fitness)
{
bestindividual=population[i];
best_index=i;
}
else if (population[i].fitness{
worstindividual=population[i];
worst_index=i;

}
sum+=population[i].fitness;
}
if (generation==0)
{
currentbest=bestindividual;
}
else
{
if(bestindividual.fitness>=currentbest.fitness)
{
currentbest=bestindividual;
}
}
}

void PerformEvolution(void)
{
if (bestindividual.fitness>currentbest.fitness)
{
currentbest=population[best_index];
}
else
{
population[worst_index]=currentbest;
}
}
void SelectionOperator(void)
{
int i,index;
double p,sum=0.0;
double cfitness[POPSIZE];
struct individual newpopulation[POPSIZE];

for(i=0;i{
sum+=population[i].fitness;
}
for(i=0;i{
cfitness[i]=population[i].fitness/sum;
}
for(i=1;i{
cfitness[i]=cfitness[i-1]+cfitness[i];
}
for (i=0;i{
p=rand()%1000/1000.0;
index=0;
while (p>cfitness[index])
{
index++;
}
newpopulation[i]=population[index];
}
for(i=0;i{
population[i]=newpopulation[i];
}
}

void CrossoverOperator(void)
{
int i,j;
int index[POPSIZE];
int point,temp;
double p;

char ch;


for (i=0;i{
index[i]=i;
}
for (i=0;i{
point=rand()%(PopSize-i);
temp=index[i];
index[i]=index[point+i];
index[point+i]=temp;
}
for (i=0;i{
p=rand()%1000/1000.0;
if (p{

point=rand()%(CHROMLENGTH-1)+1;
for (j=point; j{

ch=population[index[i]].chrom[j];
population[index[i]].chrom[j]=population[index[i+1]].chrom[j];
population[index[i+1]].chrom[j]=ch;
}
}
}
}

void MutationOperator(void)
{
int i,j;
double p;

for (i=0;i{
for(j=0;j{
p=rand()%1001/1000.0;
if (p{
population[i].chrom[j]=(population[i].chrom[j]==0)?'1':'0';
}
}
}

}
void OutputTextReport(void)
{
int i;
double sum;
double average;
sum=0.0;
for(i=0;i{
sum+=population[i].value;
}
average=sum/PopSize;
printf("gen=%d,avg=%f,best=%f,",generation,average,currentbest.value);
printf("chromosome

=");
for (i=0;i{
printf("%c",currentbest.chrom[i]);
}
printf("\n");
}