差分进化算法 C语言实现

之前的一篇中贴出了自己研究生期间C实现的基本粒子群算法，执行速度显然要比其他的高级语言快，这也是各个编程语言之间的差别，现在对于曾经辉煌过的差分进化算法进行C语言实现。变异策略采用DE/rand/1，这个是最常见的。有错误之处请之处。

/***************Differential Evolution Algorithm*************************/
/*
* @Author: Gong Xu
* (c) Copyright 2018 ，DSP Laboratory of Lanzhou University of Technology, All rights reserved. 
*
*/

# include<stdio.h>
# include<time.h>
# include<stdlib.h>
#include <string.h>
#define nVar 30  // Number of variables
#define nPop 50   // Number of Population
#define Iter 1000  // Maximum number of iterations

struct individual
{
	double position[nVar];
	double fitness;

};

struct DE
{
	struct individual ptcle[nPop];
	double F;
	double CR;
	double(*function)(double *);  // Function pointer definition
	double global_fitness;
	double global_solution[nVar];
	double x_low_bound;
	double x_up_bound;


};
// sum(X^2)
double function_fitness(double *var)
{
	double result = 0;
	for (int i = 0; i<nVar; i++)
	{
		result += *(var + i)* *(var + i);// method one : pointer
		//result += var[i] * var[i];     // method two : array
	}
	return result;
}




void runde(double F, double CR, double x_low_bound, double x_up_bound, double(*function_fitness)(double *))
{

	struct DE de;
	de.F = F;
	de.CR= CR;
	de.x_low_bound = x_low_bound;
	de.x_up_bound = x_up_bound;
	de.function =function_fitness;
	
	srand((unsigned)time(NULL));
	// inital de for iteration program
	for (int i = 0; i<nPop; i++)
	{
		for (int j = 0; j<nVar; j++)
		{
			double randx = (double)rand() / RAND_MAX;
			de.ptcle[i].position[j] = de.x_low_bound + (de.x_up_bound - de.x_low_bound)*randx;
		}
		de.ptcle[i].fitness = de.function(de.ptcle[i].position);
	}
	
	memcpy(&de.global_solution, &de.ptcle[0].position, sizeof(double)*nVar);
	de.global_fitness = de.ptcle[0].fitness;
	struct individual mutate[nPop];
	struct individual cross[nPop];

	// End of initialization 
	for (int it = 1; it <= Iter; it++)
	{	
		// mutate 
		for (int i = 0; i < nPop; i++)
		{

			int rand1 = (int)rand() % nPop;

			int rand2 = (int)rand() % nPop;

			int rand3 = (int)rand() % nPop;
			if(rand1 == i || rand2 == i || rand3 == i || rand1 == rand2 || rand2 == rand3)
			{

				 rand1 = (int)rand() % nPop;

				 rand2 = (int)rand() % nPop;

				 rand3 = (int)rand() % nPop;
			}
			for (int j = 0; j<nVar; j++)
			{
				mutate[i].position[j] = de.ptcle[rand1].position[j] + F*(de.ptcle[rand2].position[j] - de.ptcle[rand3].position[j]);
				if (mutate[i].position[j] > de.x_up_bound)
				{
					mutate[i].position[j] = de.x_up_bound;
				}
				if (mutate[i].position[j] < de.x_low_bound)
				{
					mutate[i].position[j] = de.x_low_bound;
				}
			}
		 }
		
		//crossover
		for (int i = 0; i < nPop; i++)
		{

			int randc = (int)rand() % nVar;
			for (int j = 0; j < nVar; j++)
			{
				double rand_cr = (double)rand() / RAND_MAX;
				if ((j == randc) || (rand_cr < de.CR))
				{
					cross[i].position[j] = mutate[i].position[j];
				}
				else
				{
					cross[i].position[j] = de.ptcle[i].position[j];
				}
				// limit of variables of bound
				if (cross[i].position[j] > de.x_up_bound)
				{
					cross[i].position[j] = de.x_up_bound;
				}
				if (cross[i].position[j] < de.x_low_bound)
				{
					cross[i].position[j] = de.x_low_bound;
				}
			}
			
			cross[i].fitness = de.function(cross[i].position);
		}
		// select
		for (int i = 0; i < nPop; i++)
		{
			if (cross[i].fitness < de.ptcle[i].fitness)
			{
				de.ptcle[i].fitness = cross[i].fitness;
				memcpy(&de.ptcle[i].position, &cross[i].position, sizeof(double)*nVar);
				
				if (de.ptcle[i].fitness<de.global_fitness)
				{
					de.global_fitness = de.ptcle[i].fitness;
					memcpy(&de.global_solution, &de.ptcle[i].position, sizeof(double)*nVar);
				}
			}
			
		 }
		

		// 一次迭代结束
		printf("This is %d iteration, globalfitness is %f\n ", it, de.global_fitness);
	}
	printf("The iteration is end, show the soultion and fitness!\n");
	printf("global_fitness :%f\n", de.global_fitness);
	for (int i = 0; i < nVar; i++)
	{
		printf("%f,", de.global_solution[i]);
	}
}

void main(void)
{	// Test the running time of the program . including time.h
	printf("the program is running!\n");
	clock_t pro_start, pro_finished;
	pro_start = clock();
	runde(0.8, 0.4, -100.0, 100.0, function_fitness);
	pro_finished = clock();
	double Total_time = (double)(pro_finished - pro_start) / CLOCKS_PER_SEC;
	printf("the program ran for : %3f second", Total_time);
	system("pause");
}