遗传算法案例分析及源代码
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python遗传算法代码遗传算法是一种基于生物进化原理的优化算法,适用于解决复杂问题。
在Python中,可以使用遗传算法库DEAP (Distributed Evolutionary Algorithms in Python)来实现遗传算法。
DEAP是一个灵活且易于使用的遗传算法框架,提供了用于定义和执行遗传算法的工具。
下面介绍如何使用DEAP库来实现一个简单的遗传算法。
首先,需要安装DEAP库。
可以使用以下命令来安装:```pip install deap```接下来,我们开始编写遗传算法的代码示例。
下面是一个寻找函数f(x)的最小值的例子:```pythonimport randomfrom deap import base, creator, tools# 定义目标函数def f(x):return x**2 + 4*x + 4# 创建遗传算法的环境creator.create("FitnessMin", base.Fitness, weights=(-1.0,)) creator.create("Individual", list, fitness=creator.FitnessMin)# 初始化遗传算法的参数toolbox = base.Toolbox()toolbox.register("attr_float", random.uniform, -10, 10) toolbox.register("individual", tools.initRepeat, creator.Individual, toolbox.attr_float, n=1)toolbox.register("population", tools.initRepeat, list,toolbox.individual)# 定义评估函数def evaluate(individual):x = individual[0]return f(x),# 定义遗传算法的操作toolbox.register("evaluate", evaluate)toolbox.register("select", tools.selTournament, tournsize=3) toolbox.register("mate", tools.cxTwoPoint)toolbox.register("mutate", tools.mutGaussian, mu=0, sigma=1, indpb=0.1)# 设置遗传算法的参数population_size = 100n_generations = 100cxpb = 0.5mutpb = 0.2# 创建初始种群population = toolbox.population(n=population_size)# 进化for generation in range(n_generations):offspring = toolbox.select(population, len(population))offspring = [toolbox.clone(ind) for ind in offspring]for child1, child2 in zip(offspring[::2], offspring[1::2]):if random.random() < cxpb:toolbox.mate(child1, child2)del child1.fitness.valuesdel child2.fitness.valuesfor mutant in offspring:if random.random() < mutpb:toolbox.mutate(mutant)del mutant.fitness.valuesinvalid_ind = [ind for ind in offspring if not ind.fitness.valid] fitnesses = toolbox.map(toolbox.evaluate, invalid_ind)for ind, fit in zip(invalid_ind, fitnesses):ind.fitness.values = fitpopulation[:] = offspring# 输出最优解best_individual = tools.selBest(population, k=1)[0]best_fitness = evaluate(best_individual)[0]print("Best individual:", best_individual)print("Best fitness:", best_fitness)```在上面的代码中,首先定义了目标函数f(x),然后创建了遗传算法的环境,包括创建适应度函数和个体类,以及注册遗传算法的操作。
遗传算法代码python一、简介遗传算法是一种通过模拟自然选择和遗传学原理来寻找最优解的优化算法。
它广泛应用于各种领域,包括优化问题、搜索和机器学习等。
二、代码概述以下是一个简单的遗传算法的Python代码示例,用于解决简单的优化问题。
该算法使用一个简单的二进制编码方式,并使用适应度函数来评估每个个体的适应度。
三、代码实现```pythonimportnumpyasnp#遗传算法参数POPULATION_SIZE=100#种群规模CROSSOVER_RATE=0.8#交叉概率MUTATION_RATE=0.1#变异概率MAX_GENERATIONS=100#最大迭代次数#适应度函数deffitness(individual):#在这里定义适应度函数,评估每个个体的适应度#这里简单地返回个体值的平方,可以根据实际问题进行调整returnnp.sum(individual**2)#初始种群生成pop=np.random.randint(2,size=(POPULATION_SIZE,))#迭代过程forgenerationinrange(MAX_GENERATIONS):#评估种群中每个个体的适应度fitness_values=np.apply_along_axis(fitness,1,pop)#选择种群selected_idx=np.random.choice(np.arange(POPULATION_SIZE), size=POPULATION_SIZE,replace=True,p=fitness_values/fitness_va lues.sum())selected_pop=pop[selected_idx]#交叉操作ifCROSSOVER_RATE>np.random.rand():cross_points=np.random.rand(POPULATION_SIZE,2)<0.5#随机选择交叉点cross_pop=np.array([np.hstack((individual[cross_points[i, 0]:cross_points[i,1]]+individual[cross_points[i,1]:],other))f ori,otherinenumerate(selected_pop)]).T#合并个体并随机交叉得到新的个体cross_pop=cross_pop[cross_points]#将交叉后的个体重新排列成原始种群大小selected_pop=np.vstack((selected_pop,cross_pop))#将新个体加入种群中#变异操作ifMUTATION_RATE>np.random.rand():mutated_pop=selected_pop+np.random.randn(POPULATION_SIZE, 1)*np.sqrt(np.log(POPULATION_SIZE))*(selected_pop!=pop).astyp e(np.float)#根据变异概率对个体进行变异操作,得到新的个体种群mutated_pop=mutated_pop[mutated_pop!=0]#将二进制种群中值为0的个体去掉,因为这些个体是随机的二进制串,不是解的一部分,不应该参与变异操作selected_pop=mutated_pop[:POPULATION_SIZE]#将新种群中除最后一个以外的部分加入原始种群中(即新的种群被排除了适应度最差的个体)#选择当前最好的个体(用于更新最优解)best_idx=np.argmax(fitness_values)best_solution=selected_pop[best_idx]print(f"Generation{generation}:Bestsolution:{best_solutio n}")```四、使用示例假设要解决一个简单的优化问题:求一个一维函数的最小值。
遗传算法代码# iiiclude<stdio.h>#mclude<stnng.h> #mclude<stdlib.h> #mclude<math.h> #mclude<tmie.h>^define cities 10 〃城市的个数 ^define MAXX ]00//迭代次数 #define pc 0.8 〃交配概率 #define pm 0.05 〃变异概率 ^define num 10〃种群的人小 int bestsolution;//最优染色体int distance[cities] [cities];// 城市之间的距离stmct group //染色体的结构{int city [cities];// 城市的顺序int adapt;// 适应度 double p 〃在种群中的幸存概率} group [num] ,grouptemp [num];〃随机产生10个城市之间的相互距离 voidinit(){intij ;meniset(distance.0.sizeof(distance)); srand((uiisigned)tuue(NULL)); fbr(i=O ;i<cities;i++){fbr(j=i+l ;j<cities J++){distance [i] [j]=rand()% 100; distance[j][i]=distance[i]Ij];} }fbr(i=O;i<cities;i++)printf( ”************ 城市的距离矩阵如下************\ii n );pruitf(M%4d H,distance[i][j]);}}〃随机产生初试群void groupproduceQ{mt i j 丄k,flag;fbi(i=O ;i<num; i++) //初始化for(j=OJ<citiesj++) group[i].city[j]=-l;srand((uiisigned)tuue(NULL));fbi(i=O ;i<num: i++)血(J=Oj<citi 亡s;){ t=rand()%cities;flag=l;for(k=0;k<j;k++){if(group[i] .city[k]=t){flag=O;break:}} if(flag){group[i].city|j]=t; J++;}}}pnntfC************ 初始种群如下^***************^);fbi(i=0;i<num: i++)血(J=0 J <citi 亡s;j++) pimtf(M%4d,\gioup[i].city[j]);〃评价函数,找岀最优染色体void pmgjiaQint ij;iiit nl,ii2;mt sumdistance5biggestsum=O; double biggestp=O;fdr(i=O;i<num; i++){sumdistance=O;{nl=group[i].city|j-l];n2=group[i].city[j]; sumdistance4-=distance[nl][n2];}group [1] .adapt=sumd istaiice; 〃每条染色体的路径总和biggestsum+=sumdistance; 〃种群的总路径}fbi(i=O ;i<num: i++){group [i].p= 1 -(double)gioup(i] .adapt/(double)biggestsum;biggestp+=group[i].p;}fbi(i=O ;i<num: i++)gioup[i] .p=gioup[i] .p./biggestp;〃求最佳路劲bestsolution=0;fbi(i=O ;i<num: i++) if(gioup[i].p>gioup[bestsolution].p) bestsolution=i; }〃选择void xuanzeQ{mt ij^temp;double gradient[num]^/梯度概率double xuaiize[num];//选择染色体的随机概率mt xuaii[num];//选择了的染色体〃初始化梯度概率fbi(i=O ;i<num: i++)gradient[i]=O.O; xuaiize[i]=O.O;}gradient[0]=gioup[0].p;fbr(i= 1 ;i<num:i++)gradient[i]=gradient[i-1 ]+group[i] .p; srand((uiisigned)tune(NULL));〃随机产生染色体的存活概率fdr(i=O;i<num: i++){xuanze[i]=(rand()% 100); xuaiize[i]/=100;}〃选择能生存的染色体fdr(i=0;i<num: i++){{if(xu aiize [i] <gradient [j ]){xuan[i]=j; //第i个位置存放第j个染色体break;}}}〃拷贝种群fdr(i=0;i<num: i++){grouptenip [i]. adapt=gioup [i].adapt;giouptemp[i] .p=group[i] .p;fbi(j=0 j <cities;j ++)grouptenip [i].citv|j]=group [i]. c ity[j ];}〃数据更新fdr(i=0;i<num: i++){temp=xuan[i];groupfi] .adapt=giouptemp[temp] .adapt;group [1] .p=giouptemp [temp] .p;fbi(j=0 j <cities;j ++)group[i].city[j]=grouptemp[tenip].city[j];〃变异void bianyiQ{intij;mt t;mt temp 1 ,temp2.point;double buinyip[num]; 〃染色体的变异概率mtbianyiflag[num];//染色体的变异情况fbi(i=O ;i<num: i++)〃初始化bianyiflag[i]=O;〃随机产生变异概率srand((uiisigned)tune(NULL));fbi(i=O ;i<num: i++){bianyip[i]=(rand()% 100); bianyip[i]/=100;}〃确定可以变异的染色体t=0;for(i=0 ;i<num; i++){if(biaiivip[i]<pm){ biaiiviflag[i]=l; t++;}}〃变异操作,即交换染色体的两个节点srand((iuisigned)tiine(NULL));for(i=0 ;i<num; i++){if(biaiiviflag[i]== 1){templ=rand()%10;temp2=rand()% 10;pomt=group[i]・ city[temp 1 ]; group [i]. city [temp1 ]=gioup [1]. city [temp2 ]; group[i] .city[temp2]=pomt;o e :a【n d(XXVINV£3n¥fo C T bB U T doQonpo】ddno・bb O -S Hg o q o ・Teqo「(£2】o o y )U S S A S()UTCU 二UTo lunp 」f (A R §o q o )2wl^20q o ^.・o %w uc o sXUTPsqsns^******** ***************^f l 】0 A)近士定—障尉QTry f ******************5-:************* **********⑧ 琛c>^建翠 唳********************=)七.s】d宀(dcl.mdno乩z'uxpt%-®^^・・)七宀「(曰目。
遗传算法代码遗传算法是一种基于自然选择和遗传学原理的优化算法,用于解决许多复杂的优化问题,如机器学习、图像处理、组合优化等。
以下是一个简单的遗传算法代码示例:1. 初始化种群首先,我们需要创建一组初始个体,称为种群。
每个个体都是由一组基因表示的,这些基因可能是一些数字、布尔值或其他类型的值。
我们可以使用随机数生成器生成这些基因,并将它们组合成一个个体。
2. 适应度函数为了衡量每个个体的表现,我们需要编写一个适应度函数。
该函数将计算每个个体的适应度得分,该得分反映了该个体在解决优化问题方面的能力。
适应度函数将对每个个体进行评分,并将其分配到一个适应度等级。
3. 选择操作选择操作是基于每个个体的适应度得分来选择哪些个体将被选择并用于生成下一代种群。
较高适应度的个体将有更高的概率被选择,而较低适应度的个体将有更低的概率被选择。
这通常是通过轮盘赌选择方法实现的。
4. 交叉操作交叉操作是将两个个体的基因组合并以生成新的个体。
我们可以将两个随机个体中的某些基因进行交换,从而创建新的个体。
这样的交叉操作将增加种群的多样性,使其更有可能找到最优解。
5. 变异操作变异操作是用于引入种群中的随机性的操作。
在变异操作中,我们将随机选择一个个体,并随机更改其中的一个或多个基因。
这将引入新的、未经探索的基因组合,从而增加种群的多样性。
6. 迭代随着种群不断进化,每个个体的适应度得分也将不断提高。
我们将重复执行选择、交叉和变异操作,以生成新的个体,并淘汰旧的个体。
这个不断迭代的过程将继续,直到达到预设的迭代次数或找到最优解为止。
这是一个简单的遗传算法代码示例,它演示了如何使用遗传算法来解决优化问题。
在实际应用中,我们可以进一步对算法进行优化,以获得更好的结果。
环境配置1.安装anaconda,并配置环境变量2.Win+R运行cmd打开命令行窗口,在命令行中创建并激活所需的Python环境,也可直接使用默认的base环境a)创建:conda create -n [新环境的名字] python=[Python版本号]比如:conda create -n myEnv python=3.7b)激活环境:conda activate [环境名]。
激活成功后命令行前面会有个括号显示当前使用的环境名:3.检查当前环境下是否已有需要用到的库,若没有,则需要安装a)查询命令:conda listb)安装新的库:conda install [库名]也可指定库的版本号:conda install [库名]=[版本号]4.执行指定的python文件:python [.py文件名]如果.py文件不在当前路径下,需要指定文件的完整路径完成下列实验1,2以及3、4、5任选其二。
实验1:产生式系统1.基本要求1.1掌握产生式系统的基本原理1.2运行产生式系统的示例代码1.3尝试向示例代码中添加新数据,并完成相应的推理2.实验报告2.1总结产生式系统的基本原理2.2产生式系统的源代码分析与实验记录2.3尝试向示例代码中添加新数据,并完成相应的推理3.作业无实验2:AStar求解八数码问题1.基本要求1.1掌握AStar算法的基本原理1.2编写并运行AStar算法求解八数码问题的示例代码。
给定矩阵初始状态,允许将0与相邻的4个数字之一交换,直到矩阵转变为目标状态。
输出每一步交换后的矩阵例12.实验报告2.1 总结AStar算法的基本原理2.2 如何描述八数码问题中两个状态间的距离?2.2 如何根据状态距离将八数码问题转换为AStar寻路问题?3.作业提交编写的AStar求解八数码问题代码实验3:AStar求解迷宫寻路问题1.基本要求1.1掌握AStar算法的基本原理1.2编写并运行AStar算法求解迷宫寻路问题的示例代码。
python遗传算法代码遗传算法是一种模拟生物进化过程的优化算法,常用于解决复杂的优化问题。
Python是一种简单易用且功能强大的编程语言,非常适合实现遗传算法。
下面是一个简单的Python遗传算法代码示例,用于求解一个二进制字符串中最长连续1的长度。
```pythonimport random# 设置遗传算法的参数POPULATION_SIZE = 100 # 种群大小GENERATION_COUNT = 50 # 迭代次数MUTATION_RATE = 0.01 # 变异率# 初始化种群def initialize_population():population = []for i in range(POPULATION_SIZE):individual = []for j in range(10): # 假设二进制字符串长度为10gene = random.randint(0, 1)individual.append(gene)population.append(individual)return population# 计算适应度def calculate_fitness(individual):fitness = 0current_streak = 0for gene in individual:if gene == 1:current_streak += 1fitness = max(fitness, current_streak)else:current_streak = 0return fitness# 选择操作:轮盘赌选择def selection(population):total_fitness = sum([calculate_fitness(individual) for individual in population])probabilities = [calculate_fitness(individual) /total_fitness for individual in population]selected_population = []for _ in range(POPULATION_SIZE):selected_individual = random.choices(population, weights=probabilities)[0]selected_population.append(selected_individual)return selected_population# 交叉操作:单点交叉def crossover(parent1, parent2):point = random.randint(1, len(parent1) - 1)child1 = parent1[:point] + parent2[point:]child2 = parent2[:point] + parent1[point:]return child1, child2# 变异操作def mutation(individual):for i in range(len(individual)):if random.random() < MUTATION_RATE:individual[i] = 1 - individual[i] # 变异位点翻转return individual# 主函数def genetic_algorithm():population = initialize_population()for _ in range(GENERATION_COUNT):population = selection(population)# 交叉操作new_population = []for i in range(0, POPULATION_SIZE, 2):parent1 = population[i]parent2 = population[i + 1]child1, child2 = crossover(parent1, parent2)new_population.append(child1)new_population.append(child2)# 变异操作population = [mutation(individual) for individual in new_population]best_individual = max(population, key=calculate_fitness) return best_individual# 运行遗传算法best_individual = genetic_algorithm()best_fitness = calculate_fitness(best_individual)print('Best individual:', best_individual)print('Best fitness:', best_fitness)```该代码首先初始化一个种群,然后通过选择、交叉和变异操作迭代地更新种群,并最终返回适应度最高的个体。
遗传算法matlab程序代码
遗传算法(GA)是一种用于求解优化问题的算法,其主要思想是模拟
生物进化过程中的“选择、交叉、变异”操作,通过模拟这些操作,来寻
找最优解。
Matlab自带了GA算法工具箱,可以直接调用来实现遗传算法。
以下是遗传算法Matlab程序代码示例:
1.初始化
首先定义GA需要优化的目标函数f,以及GA算法的相关参数,如种
群大小、迭代次数、交叉概率、变异概率等,如下所示:
options = gaoptimset('PopulationSize',10,...
'Generations',50,...
2.运行遗传算法
运行GA算法时,需要调用MATLAB自带的ga函数,将目标函数、问
题的维度、上下界、约束条件和算法相关参数作为输入参数。
其中,上下
界和约束条件用于限制空间,防止到无效解。
代码如下:
[某,fval,reason,output,population] = ga(f,2,[],[],[],[],[-10,-10],[10,10],[],options);
3.结果分析
最后,将结果可视化并输出,可以使用Matlab的plot函数绘制出目
标函数的值随迭代次数的变化,如下所示:
plot(output.generations,output.bestf)
某label('Generation')
ylabel('Best function value')
总之,Matlab提供了方便易用的GA算法工具箱,开发者只需要根据具体问题定义好目标函数和相关参数,就能够在短时间内快速实现遗传算法。
题目:通信网络链路容量和流量优化遗传算法MATLAB源码function [Zp,Xp,Yp,LC1,LC2]=GACFA(M,N,Pm)%--------------------------------------------------------------------------% GACFA.m% Genetic Algorithm for Capacity and Flow Assignment% 链路容量和流量优化分配的遗传算法% GreenSim团队原创作品,转载请注明% 更多原创代码,请访问GreenSim团队主页:/greensim% 算法设计、代写程序,欢迎访问GreenSim——算法仿真团队→/greensim%--------------------------------------------------------------------------% 函数功能% 使用遗传算法求解通信网链路容量和流量联合优化分配问题%--------------------------------------------------------------------------% 参考文献% 叶大振,吴新余.基于遗传算法的计算机通信网优化设计[J].% 南京邮电学院学报.1996,16(2):9-15%--------------------------------------------------------------------------% 输入参数列表% M 遗传进化迭代次数% N 种群规模(取偶数)% Pm 变异概率%--------------------------------------------------------------------------% 输出参数列表% Zp 目标函数最优值% Xp 路由选择决策变量最优值% Yp 线路型号决策变量最优值% LC1 收敛曲线1,各代最优个体适应值的记录% LC2 收敛曲线2,各代群体平均适应值的记录%--------------------------------------------------------------------------%第一步:载入数据和输出变量初始化load DATA_CFA;Xp=zeros(14,1);Yp=zeros(8,3);LC1=zeros(1,M);LC2=LC1;%第二步:随机产生初始种群farm_X=zeros(14,N);farm_Y=zeros(8,3*N);for i=1:Nfor j=1:2:13RAND=rand;if RAND>0.5farm_X(j,i)=1;elsefarm_X(j+1,i)=1;endendendfor i=1:Nfor j=1:8RAND=rand;if RAND<1/3farm_Y(j,3*i-2)=1;elseif RAND>2/3farm_Y(j,3*i)=1;elsefarm_Y(j,3*i-1)=1;endendendcounter=0;%设置迭代计数器while counter<M%停止条件为达到最大迭代次数%第三步:交叉newfarm_X=zeros(14,N);newfarm_Y=zeros(8,3*N);Ser=randperm(N);%对X做交叉for i=1:2:(N-1)A_X=farm_X(:,Ser(i));B_X=farm_X(:,Ser(i+1));cp=2*unidrnd(6);a_X=[A_X(1:cp);B_X((cp+1):end)];b_X=[B_X(1:cp);A_X((cp+1):end)];newfarm_X(:,i)=a_X;newfarm_X(:,i+1)=b_X;end%对Y做交叉for i=1:2:(N-1)A_Y=farm_Y(:,(3*Ser(i)-2):(3*Ser(i)));B_Y=farm_Y(:,(3*Ser(i+1)-2):(3*Ser(i+1))); cp=unidrnd(7);a_Y=[A_Y(1:cp,:);B_Y((cp+1):end,:)];b_Y=[B_Y(1:cp,:);A_Y((cp+1):end,:)];newfarm_Y(:,(3*i-2):(3*i))=a_Y;newfarm_Y(:,(3*i+1):(3*i+3))=b_Y;end%新旧种群合并FARM_X=[farm_X,newfarm_X];FARM_Y=[farm_Y,newfarm_Y];%第四步:选择复制Ser=randperm(2*N);FITNESS=zeros(1,2*N);fitness=zeros(1,N);for i=1:(2*N)X=FARM_X(:,i);Y=FARM_Y(:,(3*i-2):(3*i));FITNESS(i)=COST(X,Y,x1_x14,F_x1_x14,A,Q,C,S,b);endfor i=1:Nf1=FITNESS(Ser(2*i-1));f2=FITNESS(Ser(2*i));if f1<f2farm_X(:,i)=FARM_X(:,Ser(2*i-1));farm_Y(:,(3*i-2):(3*i))=FARM_Y(:,(3*Ser(2*i-1)-2):(3*Ser(2*i-1))); fitness(i)=f1;elsefarm_X(:,i)=FARM_X(:,Ser(2*i));farm_Y(:,(3*i-2):(3*i))=FARM_Y(:,(3*Ser(2*i)-2):(3*Ser(2*i)));fitness(i)=f2;endend%记录最佳个体和收敛曲线minfitness=min(fitness);meanfitness=mean(fitness);LC1(counter+1)=minfitness;LC2(counter+1)=meanfitness;pos=find(fitness==minfitness);Xp=farm_X(:,pos(1));Yp=farm_Y(:,(3*pos(1)-2):(3*pos(1)));Zp=minfitness;%第五步:变异for i=1:Nif Pm>randGT_X=farm_X(:,i);GT_Y=farm_Y(:,(3*i-2):(3*i));pos1=2*unidrnd(7);if GT_X(pos1)==1GT_X(pos1-1)=1;GT_X(pos1)=0;farm_X(:,i)=GT_X;elseif GT_X(pos1)==0GT_X(pos1-1)=0;GT_X(pos1)=1;farm_X(:,i)=GT_X;elseendpos2=unidrnd(8);GT_Y(pos2,:)=zeros(1,3);GT_Y(pos2,unidrnd(3))=1;endendcounter=counter+1endXp=Xp';Yp=Yp';%plot(LC1)%hold onplot(LC2)遗传算法程序:说明: fga.m 为遗传算法的主程序; 采用二进制Gray编码,采用基于轮盘赌法的非线性排名选择, 均匀交叉,变异操作,而且还引入了倒位操作!function[BestPop,Trace]=fga(FUN,LB,UB,eranum,popsize,pCross,pMutation,pInversion,options)% [BestPop,Trace]=fmaxga(FUN,LB,UB,eranum,popsize,pcross,pmutation)% Finds a maximum of a function of several variables.% fmaxga solves problems of the form:% max F(X) subject to: LB <= X <= UB% BestPop - 最优的群体即为最优的染色体群% Trace - 最佳染色体所对应的目标函数值% FUN - 目标函数% LB - 自变量下限% UB - 自变量上限% eranum - 种群的代数,取100--1000(默认200)% popsize - 每一代种群的规模;此可取50--200(默认100)% pcross - 交叉概率,一般取0.5--0.85之间较好(默认0.8)% pmutation - 初始变异概率,一般取0.05-0.2之间较好(默认0.1)% pInversion - 倒位概率,一般取0.05-0.3之间较好(默认0.2)% options - 1*2矩阵,options(1)=0二进制编码(默认0),option(1)~=0十进制编%码,option(2)设定求解精度(默认1e-4)%% ------------------------------------------------------------------------T1=clock;if nargin<3, error('FMAXGA requires at least three input arguments'); endif nargin==3,eranum=200;popsize=100;pCross=0.8;pMutation=0.1;pInversion=0.15;options=[0 1e-4];endif nargin==4, popsize=100;pCross=0.8;pMutation=0.1;pInversion=0.15;options=[0 1e-4];end if nargin==5, pCross=0.8;pMutation=0.1;pInversion=0.15;options=[0 1e-4];endif nargin==6, pMutation=0.1;pInversion=0.15;options=[0 1e-4];endif nargin==7, pInversion=0.15;options=[0 1e-4];endif find((LB-UB)>0)error('数据输入错误,请重新输入(LB<UB):');ends=sprintf('程序运行需要约%.4f 秒钟时间,请稍等......',(eranum*popsize/1000));disp(s);global m n NewPop children1 children2 VarNumbounds=[LB;UB]';bits=[];VarNum=size(bounds,1);precision=options(2);%由求解精度确定二进制编码长度bits=ceil(log2((bounds(:,2)-bounds(:,1))' ./ precision));%由设定精度划分区间[Pop]=InitPopGray(popsize,bits);%初始化种群[m,n]=size(Pop);NewPop=zeros(m,n);children1=zeros(1,n);children2=zeros(1,n);pm0=pMutation;BestPop=zeros(eranum,n);%分配初始解空间BestPop,TraceTrace=zeros(eranum,length(bits)+1);i=1;while i<=eranumfor j=1:mvalue(j)=feval(FUN(1,:),(b2f(Pop(j,:),bounds,bits)));%计算适应度end[MaxValue,Index]=max(value);BestPop(i,:)=Pop(Index,:);Trace(i,1)=MaxValue;Trace(i,(2:length(bits)+1))=b2f(BestPop(i,:),bounds,bits);[selectpop]=NonlinearRankSelect(FUN,Pop,bounds,bits);%非线性排名选择[CrossOverPop]=CrossOver(selectpop,pCross,round(unidrnd(eranum-i)/eranum));%采用多点交叉和均匀交叉,且逐步增大均匀交叉的概率%round(unidrnd(eranum-i)/eranum)[MutationPop]=Mutation(CrossOverPop,pMutation,VarNum);%变异[InversionPop]=Inversion(MutationPop,pInversion);%倒位Pop=InversionPop;%更新pMutation=pm0+(i^4)*(pCross/3-pm0)/(eranum^4);%随着种群向前进化,逐步增大变异率至1/2交叉率p(i)=pMutation;i=i+1;endt=1:eranum;plot(t,Trace(:,1)');title('函数优化的遗传算法');xlabel('进化世代数(eranum)');ylabel('每一代最优适应度(maxfitness)');[MaxFval,I]=max(Trace(:,1));X=Trace(I,(2:length(bits)+1));hold on; plot(I,MaxFval,'*');text(I+5,MaxFval,['FMAX=' num2str(MaxFval)]);str1=sprintf('进化到 %d 代 ,自变量为 %s 时,得本次求解的最优值 %f\n对应染色体是:%s',I,num2str(X),MaxFval,num2str(BestPop(I,:)));disp(str1);%figure(2);plot(t,p);%绘制变异值增大过程T2=clock;elapsed_time=T2-T1;if elapsed_time(6)<0elapsed_time(6)=elapsed_time(6)+60; elapsed_time(5)=elapsed_time(5)-1;endif elapsed_time(5)<0elapsed_time(5)=elapsed_time(5)+60;elapsed_time(4)=elapsed_time(4)-1;end %像这种程序当然不考虑运行上小时啦str2=sprintf('程序运行耗时 %d 小时 %d 分钟 %.4f 秒',elapsed_time(4),elapsed_time(5),elapsed_time(6));disp(str2);TSP问题遗传算法matlab源程序(注释详细,经反复实验收敛速度快)%TSP问题(又名:旅行商问题,货郎担问题)遗传算法通用matlab程序%D是距离矩阵,n为种群个数,建议取为城市个数的1~2倍,%C为停止代数,遗传到第 C代时程序停止,C的具体取值视问题的规模和耗费的时间而定%m为适应值归一化淘汰加速指数 ,最好取为1,2,3,4 ,不宜太大%alpha为淘汰保护指数,可取为0~1之间任意小数,取1时关闭保护功能,最好取为0.8~1.0%R为最短路径,Rlength为路径长度function [R,Rlength]=geneticTSP(D,n,C,m,alpha)[N,NN]=size(D);farm=zeros(n,N);%用于存储种群for i=1:nfarm(i,=randperm(N);%随机生成初始种群endR=farm(1,;%存储最优种群len=zeros(n,1);%存储路径长度fitness=zeros(n,1);%存储归一化适应值counter=0;while counter<Cfor i=1:nlen(i,1)=myLength(D,farm(i,);%计算路径长度endmaxlen=max(len);minlen=min(len);fitness=fit(len,m,maxlen,minlen);%计算归一化适应值 rr=find(len==minlen);R=farm(rr(1,1),;%更新最短路径FARM=farm;%优胜劣汰,nn记录了复制的个数nn=0;for i=1:nif fitness(i,1)>=alpha*randnn=nn+1;FARM(nn,=farm(i,;endendFARM=FARM(1:nn,;[aa,bb]=size(FARM);%交叉和变异while aa<nif nn<=2nnper=randperm(2);elsennper=randperm(nn);endA=FARM(nnper(1),;B=FARM(nnper(2),;[A,B]=intercross(A,B);FARM=[FARM;A;B];[aa,bb]=size(FARM);endif aa>nFARM=FARM(1:n,;%保持种群规模为nendfarm=FARM;clear FARMcounter=counter+1endRlength=myLength(D,R);function [a,b]=intercross(a,b)L=length(a);if L<=10%确定交叉宽度W=1;elseif ((L/10)-floor(L/10))>=rand&&L>10W=ceil(L/10);elseW=floor(L/10);endp=unidrnd(L-W+1);%随机选择交叉范围,从p到p+Wfor i=1:W%交叉x=find(a==b(1,p+i-1));y=find(b==a(1,p+i-1));[a(1,p+i-1),b(1,p+i-1)]=exchange(a(1,p+i-1),b(1,p+i-1));[a(1,x),b(1,y)]=exchange(a(1,x),b(1,y));endfunction [x,y]=exchange(x,y)temp=x;x=y;y=temp;% 计算路径的子程序function len=myLength(D,p)[N,NN]=size(D);len=D(p(1,N),p(1,1));for i=1N-1)len=len+D(p(1,i),p(1,i+1));end%计算归一化适应值子程序function fitness=fit(len,m,maxlen,minlen)fitness=len;for i=1:length(len)fitness(i,1)=(1-((len(i,1)-minlen)/(maxlen-minlen+0.000001))).^m; end%初始化种群%采用二进制Gray编码,其目的是为了克服二进制编码的Hamming悬崖缺点function [initpop]=InitPopGray(popsize,bits)len=sum(bits);initpop=zeros(popsize,len);%The whole zero encoding individualfor i=2:popsize-1pop=round(rand(1,len));pop=mod(([0 pop]+[pop 0]),2);%i=1时,b(1)=a(1);i>1时,b(i)=mod(a(i-1)+a(i),2)%其中原二进制串:a(1)a(2)...a(n),Gray串:b(1)b(2)...b(n)initpop(i,:)=pop(1:end-1);endinitpop(popsize,:)=ones(1,len);%The whole one encoding individual%解码function [fval] = b2f(bval,bounds,bits)% fval - 表征各变量的十进制数% bval - 表征各变量的二进制编码串% bounds - 各变量的取值范围% bits - 各变量的二进制编码长度scale=(bounds(:,2)-bounds(:,1))'./(2.^bits-1); %The range of the variablesnumV=size(bounds,1);cs=[0 cumsum(bits)];for i=1:numVa=bval((cs(i)+1):cs(i+1));fval(i)=sum(2.^(size(a,2)-1:-1:0).*a)*scale(i)+bounds(i,1);end%选择操作%采用基于轮盘赌法的非线性排名选择%各个体成员按适应值从大到小分配选择概率:%P(i)=(q/1-(1-q)^n)*(1-q)^i, 其中 P(0)>P(1)>...>P(n), sum(P(i))=1function [selectpop]=NonlinearRankSelect(FUN,pop,bounds,bits)global m nselectpop=zeros(m,n);fit=zeros(m,1);for i=1:mfit(i)=feval(FUN(1,:),(b2f(pop(i,:),bounds,bits)));%以函数值为适应值做排名依据endselectprob=fit/sum(fit);%计算各个体相对适应度(0,1)q=max(selectprob);%选择最优的概率x=zeros(m,2);x(:,1)=[m:-1:1]';[y x(:,2)]=sort(selectprob);r=q/(1-(1-q)^m);%标准分布基值newfit(x(:,2))=r*(1-q).^(x(:,1)-1);%生成选择概率newfit=cumsum(newfit);%计算各选择概率之和rNums=sort(rand(m,1));fitIn=1;newIn=1;while newIn<=mif rNums(newIn)<newfit(fitIn)selectpop(newIn,:)=pop(fitIn,:);newIn=newIn+1;elsefitIn=fitIn+1;endend%交叉操作function [NewPop]=CrossOver(OldPop,pCross,opts)%OldPop为父代种群,pcross为交叉概率global m n NewPopr=rand(1,m);y1=find(r<pCross);y2=find(r>=pCross);len=length(y1);if len>2&mod(len,2)==1%如果用来进行交叉的染色体的条数为奇数,将其调整为偶数y2(length(y2)+1)=y1(len);y1(len)=[];endif length(y1)>=2for i=0:2:length(y1)-2if opts==0[NewPop(y1(i+1),:),NewPop(y1(i+2),:)]=EqualCrossOver(OldPop(y1(i+1),:),OldPop(y1(i+2), :));else[NewPop(y1(i+1),:),NewPop(y1(i+2),:)]=MultiPointCross(OldPop(y1(i+1),:),OldPop(y1(i+2) ,:));endendendNewPop(y2,:)=OldPop(y2,:);%采用均匀交叉function [children1,children2]=EqualCrossOver(parent1,parent2)global n children1 children2hidecode=round(rand(1,n));%随机生成掩码crossposition=find(hidecode==1);holdposition=find(hidecode==0);children1(crossposition)=parent1(crossposition);%掩码为1,父1为子1提供基因children1(holdposition)=parent2(holdposition);%掩码为0,父2为子1提供基因children2(crossposition)=parent2(crossposition);%掩码为1,父2为子2提供基因children2(holdposition)=parent1(holdposition);%掩码为0,父1为子2提供基因%采用多点交叉,交叉点数由变量数决定function [Children1,Children2]=MultiPointCross(Parent1,Parent2)global n Children1 Children2 VarNumChildren1=Parent1;Children2=Parent2;Points=sort(unidrnd(n,1,2*VarNum));for i=1:VarNumChildren1(Points(2*i-1):Points(2*i))=Parent2(Points(2*i-1):Points(2*i));Children2(Points(2*i-1):Points(2*i))=Parent1(Points(2*i-1):Points(2*i));end%变异操作function [NewPop]=Mutation(OldPop,pMutation,VarNum)global m n NewPopr=rand(1,m);position=find(r<=pMutation);len=length(position);if len>=1for i=1:lenk=unidrnd(n,1,VarNum); %设置变异点数,一般设置1点for j=1:length(k)if OldPop(position(i),k(j))==1OldPop(position(i),k(j))=0;elseOldPop(position(i),k(j))=1;endendendendNewPop=OldPop;%倒位操作function [NewPop]=Inversion(OldPop,pInversion)global m n NewPopNewPop=OldPop;r=rand(1,m);PopIn=find(r<=pInversion);len=length(PopIn);if len>=1for i=1:lend=sort(unidrnd(n,1,2));if d(1)~=1&d(2)~=nNewPop(PopIn(i),1:d(1)-1)=OldPop(PopIn(i),1:d(1)-1);NewPop(PopIn(i),d(1):d(2))=OldPop(PopIn(i),d(2):-1:d(1)); NewPop(PopIn(i),d(2)+1:n)=OldPop(PopIn(i),d(2)+1:n);endendend。
python 遗传算法求解ft06案例FT06问题是一个著名的优化问题,其目标是在给定一组权重的情况下,寻找一组权重和最小的权重的值。
在遗传算法中,我们使用“基因”来表示每个个体的特性,并使用“染色体”来表示个体的完整特性。
在FT06问题中,我们可以将每个个体的基因设置为一个实数,并使用一组权重来定义每个基因的重要性。
然后,我们使用遗传算法来找到一组权重和最小的染色体。
以下是一个使用Python编写的简单遗传算法求解FT06问题的示例代码:```pythonimport numpy as np定义适应度函数def fitness(chromosome):weights = (chromosome)return (weights)定义交叉函数def crossover(parent1, parent2):child = [x for x in parent1] + [x for x in parent2]return child定义变异函数def mutation(chromosome):prob = ()if prob < : 1%的概率发生变异i = (0, len(chromosome)) 随机选择一个基因chromosome[i] = 1 - chromosome[i] 翻转基因的值return chromosome初始化种群pop_size = 100 种群大小chrom_length = 10 染色体长度pop = (2, size=(pop_size, chrom_length)) 随机生成初始种群遗传算法主循环for generation in range(100): 迭代100代计算适应度值并排序种群fitness_values = [fitness(chromosome) for chromosome in pop] pop_sorted = ([pop[i] for i in (fitness_values)])选择操作:轮盘赌选择法for i in range(pop_size):if i < pop_size : 前80%的个体采用轮盘赌选择法选择fitness_values_sum = (fitness_values[:i + 1])prob = () fitness_values_sum / sum(fitness_values)j = 0while j < i and prob > sum(fitness_values[:j]):prob -= fitness_values[j]j += 1pop[i] = pop_sorted[j] 选择适应度值最高的个体else: 后20%的个体采用均匀选择法选择pop[i] = pop_sorted[(0, len(pop_sorted))]交叉操作:单点交叉法new_pop = []for i in range(int(pop_size ), pop_size): 前70%的个体不参与交叉操作parent1, parent2 = pop[(0, pop_size)], pop[(0, pop_size)]child = crossover(parent1, parent2)new_(child)new_pop += pop[:int(pop_size )] 将未参与交叉操作的个体加入新种群中pop = (new_pop) 更新种群变异操作:均匀变异法for i in range(int(pop_size )): 前10%的个体不参与变异操作chromosome = pop[(0, pop_size)]mutation(chromosome) 对染色体进行变异操作pop = ([mutation(chromosome) for chromosome in pop]) 对所有染色体进行变异操作,并更新种群```。
方案一的程序编码函数主文件:function[Xp,LC1,LC2,LC3]=CLBGA8(M,Pm) %%%陈璐斌编程,解决VRP问题(带时间窗)%%输入参数%M遗传进化迭代次数%Pm变异概率%%输出参数%Xp最优个体%LC1目标收敛曲线%LC2平均适应度收敛曲线%LC3最优适应度收敛曲线%%%变量初始化Xp=zeros(1,5);LC1=zeros(1,M);LC2=zeros(1,M);LC3=zeros(1,M);Best=inf;%%编码方式-第一步:产生初始种群N=10;%N 种群规模farm=cell(1,N);%存储种群的细胞结构k=1;while (N-k>=0)G=randperm(5);%产生5个客户的全排列farm{k}=G;k=k+1;end%%%进化迭代计数器counter=1;while counter<=M%%第二步:交叉%交叉采用双亲双子单点交叉N=10;%种群规模newfarm=cell(1,2*N-4);%存储子代的细胞结构Ser=randperm(N);%两两随机配对表生成for i=1:(N-2)%避免交叉概率为1 A=farm{Ser(i)};B=farm{Ser(i+1)};%取出父代P0=unidrnd(5);%随机选择交叉点aa=zeros(1,5);bb=zeros(1,5);A_=A;B_=B;for ii=1:5-P0aa(ii)=B(P0+ii);endfor ii=1:5-P0for iiii=1:5if(B(P0+ii)==A_(iiii))A_(iiii)=0;endendendfor iii=6-P0:5for iiii=1:5if(A_(iiii)~=0)aa(iii)=A_(iiii);A_(iiii)=0;breakendendendfor ii=1:5-P0bb(ii)=A(P0+ii);endfor ii=1:5-P0for iiii=1:5if(A(P0+ii)==B_(iiii))B_(iiii)=0;endendendfor iii=6-P0:5for iiii=1:5if(B_(iiii)~=0)bb(iii)=B_(iiii);B_(iiii)=0;breakendendend%产生子代newfarm{2*i-1}=aa;newfarm{2*i}=bb;endFARM=[farm,newfarm];%新旧种群合并%%第三步:选择复制%%计算当前种群适应度并存储N=10;SYZ=zeros(1,3*N-4);syz=zeros(1,3*N-4);for i=1:(3*N-4)x=FARM{i};SYZ(i)=clb8(x);end%%选择复制,较优的N个个体复制到下一代k=1;while k<=(3*N-4)maxSYZ=max(SYZ);posSYZ=find(SYZ==maxSYZ);POS=posSYZ(1);k=k+1;farm{k}=FARM{POS};syz(k)=SYZ(POS);SYZ(POS)=0;end%记录和更新,更新最优个体,记录收敛曲线数据maxsyz=max(syz);meansyz=mean(syz);pos=find(syz==maxsyz);LC2(counter+1)=meansyz;if maxsyzBest=maxsyz;Xp=farm{pos(1)};endLC3(counter+1)=Best;d=[0,6.4,3.2,3.9,3.7,2;6.4,0,2.9,2.1,4.5,4.1;3.2,2.9,0,1.5,3.3,1.2;3.9,2.1,1.5,0,3.6,2.6;3.7,4.5,3.3,3.6 ,0,3.8;...2.0,4.1,1.2,2.6,3.8,0;];%距离矩阵t=[0,0.16,0.08,0.1,0.09,0.05;0.16,0,0.07,0.05,0.11,0.1;0.08,0.07,0,0.04,0.08,0.03;...0.1,0.05,0.04,0,0.09,0.07;0.09,0.11,0.08,0.09,0,0.10;0.05,0.1,0.03,0.07,0.1,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7];xx=x;%取出染色体j=1;%分工点初始化%%取距离向量d1,d2d1=zeros(1,6);d1(1)=d(1,xx(1)+1);for i=1:4d1(i+1)=d(xx(i)+1,xx(i+1)+1);endd1(6)=d(xx(5)+1,1);%%时间窗计算T=t(1,xx(1)+1);pun1=0;if T<early(xx(1))pun1=early(xx(1))-T;T=early(xx(1));endT=T+w(xx(1));for i=2:5T=T+t(xx(i-1)+1,xx(i)+1);if T<early(xx(i))pun1=pun1+early(xx(i))-T;T=early(xx(i));endT=T+w(xx(5));endF=sum(10.*d1)+sum(10.*d2)+20*pun1; LC1(counter+1)=F;%%第四步:变异N=10;for i=1:Nif Pm>randAA=farm{i};POS1=unidrnd(5);POS2=unidrnd(5);temp=AA(POS1);AA(POS1)=AA(POS2);AA(POS2)=temp;farm{i}=AA;endendcounter=counter+1;end%%第五步:绘制收敛曲线图figure(2);plot(LC1);xlabel('迭代次数');ylabel('目标的值');title('目标的收敛曲线');figure(3);plot(LC2);xlabel('迭代次数');ylabel('适应度函数的平均值');title('平均适应度函数的收敛曲线');plot(LC3);xlabel('迭代次数');ylabel('适应度函数的最优值');title('最优适应度函数的收敛曲线');适应度文件:%%计算载重量和时间窗%%适应度函数计算function Fitness=clb8(x)d=[0,6.4,3.2,3.9,3.7,2;6.4,0,2.9,2.1,4.5,4.1;3.2,2.9,0,1.5,3.3,1.2;3.9,2.1,1.5,0,3.6,2.6;3.7,4.5,3.3,3.6 ,0,3.8;...2.0,4.1,1.2,2.6,3.8,0;];%距离矩阵t=[0,0.16,0.08,0.1,0.09,0.05;0.16,0,0.07,0.05,0.11,0.1;0.08,0.07,0,0.04,0.08,0.03;...0.1,0.05,0.04,0,0.09,0.07;0.09,0.11,0.08,0.09,0,0.10;0.05,0.1,0.03,0.07,0.1,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7];xx=x;%取出染色体j=1;%分工点初始化%%取距离向量d1,d2d1=zeros(1,6);d1(1)=d(1,xx(1)+1);for i=1:4d1(i+1)=d(xx(i)+1,xx(i+1)+1);endd1(6)=d(xx(5)+1,1);%%时间窗计算T=t(1,xx(1)+1);pun1=0;if T<early(xx(1))pun1=early(xx(1))-T;T=early(xx(1));endT=T+w(xx(1));T=T+t(xx(i-1)+1,xx(i)+1);if T<early(xx(i))pun1=pun1+early(xx(i))-T;T=early(xx(i));endT=T+w(xx(5));endF=sum(10.*d1)+sum(10.*d2)+20*pun1;Fitness=1/F;计算时间文件:function[T]=TOTALT(Xp1)Xp=Xp1;t=[0,0.16,0.08,0.1,0.09,0.05;0.16,0,0.07,0.05,0.11,0.1;0.08,0.07,0,0.04,0.08,0.03;...0.1,0.05,0.04,0,0.09,0.07;0.09,0.11,0.08,0.09,0,0.10;0.05,0.1,0.03,0.07,0.1,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7];T=t(1,Xp(1)+1);if T<early(Xp(1))T=early(Xp(1));endT=T+w(Xp(1));for i=2:5T=T+t(Xp(i-1)+1,Xp(i)+1);if T<early(Xp(i))T=early(Xp(1));endT=T+w(Xp(i));endT=T+t(1,Xp(5)+1);方案二的程序编码主函数文件:function[Xp,LC1,LC2,LC3]=CLBGA9(M,Pm)%%%陈璐斌编程,解决VRP问题(带时间窗)%%输入参数%M遗传进化迭代次数%Pm变异概率%%输出参数%Xp最优个体%LC1子目标2收敛曲线%LC2平均适应度收敛曲线%LC3最优适应度收敛曲线%%%变量初始化Xp=zeros(1,6);LC1=zeros(1,M);LC2=zeros(1,M);LC3=zeros(1,M);Best=inf;%%编码方式-第一步:产生初始种群N=10;%N 种群规模%Q=[2.4,3.3,2.1,2.7,2.3,1.6,2.0,1.2,3.6,1.9];%需求矩阵farm=cell(1,N);%存储种群的细胞结构k=1;while (N-k>=0)G=randperm(6);%产生6个客户的全排列farm{k}=G;k=k+1;end%%%进化迭代计数器counter=1;while counter<=M%%第二步:交叉%交叉采用双亲双子单点交叉N=10;%种群规模newfarm=cell(1,2*N-4);%存储子代的细胞结构Ser=randperm(N);%两两随机配对表生成for i=1:(N-2)%避免交叉概率为1A=farm{Ser(i)};B=farm{Ser(i+1)};%取出父代P0=unidrnd(6);%随机选择交叉点aa=zeros(1,6);bb=zeros(1,6);A_=A;B_=B;for ii=1:6-P0aa(ii)=B(P0+ii);endfor ii=1:6-P0for iiii=1:6if(B(P0+ii)==A_(iiii))A_(iiii)=0;endendendfor iii=7-P0:6for iiii=1:6if(A_(iiii)~=0)aa(iii)=A_(iiii);A_(iiii)=0;breakendendendfor ii=1:6-P0bb(ii)=A(P0+ii);endfor ii=1:6-P0for iiii=1:6if(A(P0+ii)==B_(iiii))B_(iiii)=0;endendendfor iii=7-P0:6for iiii=1:6if(B_(iiii)~=0)bb(iii)=B_(iiii);B_(iiii)=0;breakendendend%产生子代newfarm{2*i-1}=aa;newfarm{2*i}=bb;endFARM=[farm,newfarm];%新旧种群合并%%第三步:选择复制%%计算当前种群适应度并存储N=10;SYZ=zeros(1,3*N-4);syz=zeros(1,3*N-4);for i=1:(3*N-4)x=FARM{i};SYZ(i)=clb9(x);end%%选择复制,较优的N个个体复制到下一代k=1;while k<=(3*N-4)maxSYZ=max(SYZ);posSYZ=find(SYZ==maxSYZ);POS=posSYZ(1);k=k+1;farm{k}=FARM{POS};syz(k)=SYZ(POS);SYZ(POS)=0;end%记录和更新,更新最优个体,记录收敛曲线数据maxsyz=max(syz);meansyz=mean(syz);pos=find(syz==maxsyz);LC2(counter+1)=meansyz;if maxsyzBest=maxsyz;Xp=farm{pos(1)};endLC3(counter+1)=Best;d=[0,6.4,3.2,3.9,3.7,35,2;6.4,0,2.9,2.1,4.5,32.5,4.1;3.2,2.9,0,1.5,3.3,35.7,1.2;3.9,2.1,1.5,0,3.6,34.5,2.6;...3.7,4.5,3.3,3.6,0,37,3.8;35,32.5,35.7,34.5,37,0,38.5;2,4.1,1.2,2.6,3.8,38.5,0];%距离矩阵t=[0,0.16,0.08,0.1,0.1,0.88,0.05;0.16,0,0.07,0.05,0.11,0.81,0.1;0.08,0.07,0,0.04,0.08,0.9,0.03;...0.1,0.05,0.04,0,0.09,0.86,0.07;0.1,0.11,0.08,0.09,0,0.92,0.1;0.88,0.81,0.9,0.86,0.92,0,0.96;...0.05,0.1,0.03,0.07,0.1,0.96,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.2,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7,0.6];xx=x;%取出染色体j=1;%分工点初始化%%取距离向量d1,d2d1=zeros(1,7);d1(1)=d(1,xx(1)+1);for i=1:5d1(i+1)=d(xx(i)+1,xx(i+1)+1);endd1(7)=d(xx(6)+1,1);%%时间窗计算T=t(1,xx(1)+1);pun1=0;if T<early(xx(1))pun1=early(xx(1))-T;T=early(xx(1));endT=T+w(xx(1));for i=2:6T=T+t(xx(i-1)+1,xx(i)+1);if T<early(xx(i))pun1=pun1+early(xx(i))-T;T=early(xx(i));endT=T+w(xx(6));endF=sum(10.*d1) +20*pun1;LC1(counter+1)=F;%%第四步:变异N=10;for i=1:Nif Pm>randAA=farm{i};POS1=unidrnd(6);POS2=unidrnd(6);temp=AA(POS1);AA(POS1)=AA(POS2);AA(POS2)=temp;farm{i}=AA;endendcounter=counter+1;end%%第五步:绘制收敛曲线图figure(2);plot(LC1);xlabel('迭代次数');ylabel('目标的值');title('目标的收敛曲线');figure(3);plot(LC2);xlabel('迭代次数');ylabel('适应度函数的平均值');title('平均适应度函数的收敛曲线');figure(4);plot(LC3);xlabel('迭代次数');ylabel('适应度函数的最优值');title('最优适应度函数的收敛曲线');适应度文件:%%计算载重量和时间窗%%适应度函数计算function Fitness=clb9(x)d=[0,6.4,3.2,3.9,3.7,35,2;6.4,0,2.9,2.1,4.5,32.5,4.1;3.2,2.9,0,1.5,3.3,35.7,1.2;3.9,2.1,1.5,0,3.6,34.5,2.6;...3.7,4.5,3.3,3.6,0,37,3.8;35,32.5,35.7,34.5,37,0,38.5;2,4.1,1.2,2.6,3.8,38.5,0];%距离矩阵t=[0,0.16,0.08,0.1,0.1,0.88,0.05;0.16,0,0.07,0.05,0.11,0.81,0.1;0.08,0.07,0,0.04,0.08,0.9,0.03;...0.1,0.05,0.04,0,0.09,0.86,0.07;0.1,0.11,0.08,0.09,0,0.92,0.1;0.88,0.81,0.9,0.86,0.92,0,0.96;...0.05,0.1,0.03,0.07,0.1,0.96,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.2,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7,0.6];late=[2.5,3.4,3.3,2.7,2.5,4.5];xx=x;%取出染色体j=1;%分工点初始化%%取距离向量d1,d2d1=zeros(1,7);d1(1)=d(1,xx(1)+1);for i=1:5d1(i+1)=d(xx(i)+1,xx(i+1)+1);endd1(7)=d(xx(6)+1,1);%%时间窗计算T=t(1,xx(1)+1);pun1=0;if T<early(xx(1))pun1=early(xx(1))-T;T=early(xx(1));endT=T+w(xx(1));for i=2:6T=T+t(xx(i-1)+1,xx(i)+1);if T<early(xx(i))pun1=pun1+early(xx(i))-T;T=early(xx(i));endT=T+w(xx(6));endF=sum(10.*d1) +20*pun1;Fitness=1/F;计算时间文件:function[T]=TOTALT2(Xp1)Xp=Xp1;t=[0,0.16,0.08,0.1,0.1,0.88,0.05;0.16,0,0.07,0.05,0.11,0.81,0.1;0.08,0.07,0,0.04,0.08,0.9,0.03;...0.1,0.05,0.04,0,0.09,0.86,0.07;0.1,0.11,0.08,0.09,0,0.92,0.1;0.88,0.81,0.9,0.86,0.92,0,0.96;... 0.05,0.1,0.03,0.07,0.1,0.96,0;];%行驶时间矩阵w=[0.15,0.2,0.18,0.25,0.2,0.22];%服务时间矩阵%%时间窗向量early=[0.15,0.3,0.7,0.4,0.7,0.6];T=t(1,Xp(1)+1);if T<early(Xp(1))T=early(Xp(1));endT=T+w(Xp(1));for i=2:6T=T+t(Xp(i-1)+1,Xp(i)+1);if T<early(Xp(i))T=early(Xp(1));endT=T+w(Xp(i));endT=T+t(1,Xp(6)+1)。
遗传算法简述及代码详解声明:本文内容整理自网络,认为原作者同意转载,如有冒犯请联系我。
遗传算法基本内容遗传算法为群体优化算法,也就是从多个初始解开始进行优化,每个解称为一个染色体,各染色体之间通过竞争、合作、单独变异,不断进化。
遗传学与遗传算法中的基础术语比较染色体:又可以叫做基因型个体(individuals)群体/种群(population):一定数量的个体组成,及一定数量的染色体组成,群体中个体的数量叫做群体大小。
初始群体:若干染色体的集合,即解的规模,如30,50等,认为是随机选取的数据集合。
适应度(fitness):各个个体对环境的适应程度优化时先要将实际问题转换到遗传空间,就是把实际问题的解用染色体表示,称为编码,反过程为解码/译码,因为优化后要进行评价(此时得到的解是否较之前解优越),所以要返回问题空间,故要进行解码。
SGA采用二进制编码,染色体就是二进制位串,每一位可称为一个基因;如果直接生成二进制初始种群,则不必有编码过程,但要求解码时将染色体解码到问题可行域内。
遗传算法的准备工作:1) 数据转换操作,包括表现型到基因型的转换和基因型到表现型的转换。
前者是把求解空间中的参数转化成遗传空间中的染色体或者个体(encoding),后者是它的逆操作(decoding)2) 确定适应度计算函数,可以将个体值经过该函数转换为该个体的适应度,该适应度的高低要能充分反映该个体对于解得优秀程度。
非常重要的过程。
遗传算法基本过程为:1) 编码,创建初始群体2) 群体中个体适应度计算3) 评估适应度4) 根据适应度选择个体5) 被选择个体进行交叉繁殖6) 在繁殖的过程中引入变异机制7) 繁殖出新的群体,回到第二步实例一:(建议先看实例二)求 []30,0∈x 范围内的()210-=x y 的最小值1) 编码算法选择为"将x 转化为2进制的串",串的长度为5位(串的长度根据解的精度设 定,串长度越长解得精度越高)。
C语言遗传算法代码以下为遗传算法的源代码,计算一元代函数的代码和二元函数的代码以+++++++++++++++++++++++++++++++++++++为分割线分割开来,请自行选择适合的代码,使用时请略看完代码的注释,在需要更改的地方更改为自己需要的代码。
+++++++++++++++++++++++++++++++一元函数代码++++++++++++++++++++++++++++#include <stdio.h>#include<stdlib.h>#include<time.h>#include<math.h>#define POPSIZE 1000#define maximization 1#define minimization 2#define cmax 100#define cmin 0#define length1 20#define chromlength length1 //染色体长度//注意,你是求最大值还是求最小值int functionmode=minimization;//变量的上下限的修改开始float min_x1=-2;//变量的下界float max_x1=-1;//变量的上界//变量的上下限的修改结束int popsize; //种群大小int maxgeneration; //最大世代数double pc; //交叉率double pm; //变异率struct individual{char chrom[chromlength+1];double value;double fitness; //适应度};int generation; //世代数int best_index;int worst_index;struct individual bestindividual; //最佳个体struct individual worstindividual; //最差个体struct individual currentbest;struct individual population[POPSIZE];//函数声明void generateinitialpopulation();void generatenextpopulation();void evaluatepopulation();long decodechromosome(char *,int,int);void calculateobjectvalue();void calculatefitnessvalue();void findbestandworstindividual();void performevolution();void selectoperator();void crossoveroperator();void mutationoperator();void input();void outputtextreport();void generateinitialpopulation( ) //种群初始化{int i,j;for (i=0;i<popsize; i++){for(j=0;j<chromlength;j++){population[i].chrom[j]=(rand()%20<10)?'0':'1';}population[i].chrom[chromlength]='\0';}}void generatenextpopulation() //生成下一代{selectoperator();crossoveroperator();mutationoperator();}void evaluatepopulation() //评价个体,求最佳个体{calculateobjectvalue();calculatefitnessvalue();findbestandworstindividual();}long decodechromosome(char *string ,int point,int length) //给染色体解码{int i;long decimal=0;char*pointer;for(i=0,pointer=string+point;i<length;i++,pointer++)if(*pointer-'0'){decimal +=(long)pow(2,i);}return (decimal);}void calculateobjectvalue() //计算函数值{int i;long temp1,temp2;double x1;for (i=0; i<popsize; i++){temp1=decodechromosome(population[i].chrom,0,length1);x1=(max_x1-min_x1)*temp1/(1024*1024-1)+min_x1;//目标函数修改开始population[i].value=(pow(x1,5)-3*x1-1)*(pow(x1,5)-3*x1-1);//目标函数修改结束}}void calculatefitnessvalue()//计算适应度{int i;double temp;for(i=0;i<popsize;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<cmax){temp=cmax-population[i].value;}else{ temp=0.0;}}population[i].fitness=temp;}}void findbestandworstindividual( ) //求最佳个体和最差个体{int i;double sum=0.0;bestindividual=population[0];worstindividual=population[0];for (i=1;i<popsize; i++){if (population[i].fitness>bestindividual.fitness){bestindividual=population[i];best_index=i;}else if (population[i].fitness<worstindividual.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() //演示评价结果{if (bestindividual.fitness>currentbest.fitness){ currentbest=population[best_index];}else{population[worst_index]=currentbest;}}void selectoperator() //比例选择算法{int i,index;double p,sum=0.0;double cfitness[POPSIZE];struct individual newpopulation[POPSIZE];for(i=0;i<popsize;i++){sum+=population[i].fitness;}for(i=0;i<popsize; i++){cfitness[i]=population[i].fitness/sum;}for(i=1;i<popsize; i++){cfitness[i]=cfitness[i-1]+cfitness[i];}for (i=0;i<popsize;i++){p=rand()%1000/1000.0;index=0;while (p>cfitness[index]){index++;}newpopulation[i]=population[index];}for(i=0;i<popsize; i++){population[i]=newpopulation[i];}}void crossoveroperator() //交叉算法{int i,j;int index[POPSIZE];int point,temp;double p;char ch;for (i=0;i<popsize;i++){index[i]=i;}for (i=0;i<popsize;i++){point=rand()%(popsize-i);temp=index[i];index[i]=index[point+i];index[point+i]=temp;}for (i=0;i<popsize-1;i+=2){p=rand()%1000/1000.0;if (p<pc){point=rand()%(chromlength-1)+1;for (j=point; j<chromlength;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() //变异操作{int i,j;double p;for (i=0;i<popsize;i++){for(j=0;j<chromlength;j++){p=rand()%1000/1000.0;if (p<pm){population[i].chrom[j]=(population[i].chrom[j]=='0')?'1':'0';}}}void input() //数据输入{ //printf("初始化全局变量:\n");//printf(" 种群大小(50-500):");//scanf("%d", &popsize);popsize=500;if((popsize%2) != 0){//printf( " 种群大小已设置为偶数\n");popsize++;};//printf(" 最大世代数(100-300):");//scanf("%d", &maxgeneration);maxgeneration=200;//printf(" 交叉率(0.2-0.99):");//scanf("%f", &pc);pc=0.95;//printf(" 变异率(0.001-0.1):");//scanf("%f", &pm);pm=0.03;}void outputtextreport()//数据输出{int i;double sum;double average;sum=0.0;for(i=0;i<popsize;i++){sum+=population[i].value;}average=sum/popsize;printf("当前世代=%d\n当前世代平均函数值=%f\n当前世代最优函数值=%f\n",generation,average,population[best_index].value);}void main() //主函数{ int i;long temp1,temp2;double x1,x2;generation=0;input();generateinitialpopulation();evaluatepopulation();while(generation<maxgeneration)generation++;generatenextpopulation();evaluatepopulation();performevolution();outputtextreport();}printf("\n");printf(" 统计结果: ");printf("\n");//printf("最大函数值等于:%f\n",currentbest.fitness);printf("其染色体编码为:");for (i=0;i<chromlength;i++){printf("%c",currentbest.chrom[i]);}printf("\n");temp1=decodechromosome(currentbest.chrom,0,length1);x1=(max_x1-min_x1)*temp1/(1024*1024-1)+min_x1;printf("x1=%lf\n",x1);//这是需要修改的地方printf("最优值等于:%f\n",(pow(x1,5)-3*x1-1)*(pow(x1,5)-3*x1-1));}+++++++++++++++++++++++++二元函数代码+++++++++++++++++++++++++++++++++++++++++ #include <stdio.h>#include<stdlib.h>#include<time.h>#include<math.h>#define POPSIZE 500#define maximization 1#define minimization 2#define cmax 100#define cmin 0#define length1 20#define length2 20#define chromlength length1+length2 //染色体长度//-----------求最大还是最小值int functionmode=maximization;//-----------//-----------变量上下界float min_x1=0;float max_x1=3;float min_x2=1;float max_x2=5;//-----------int popsize; //种群大小int maxgeneration; //最大世代数double pc; //交叉率double pm; //变异率struct individual{char chrom[chromlength+1];double value;double fitness; //适应度};int generation; //世代数int best_index;int worst_index;struct individual bestindividual; //最佳个体struct individual worstindividual; //最差个体struct individual currentbest;struct individual population[POPSIZE];//函数声明void generateinitialpopulation();void generatenextpopulation();void evaluatepopulation();long decodechromosome(char *,int,int);void calculateobjectvalue();void calculatefitnessvalue();void findbestandworstindividual();void performevolution();void selectoperator();void crossoveroperator();void mutationoperator();void input();void outputtextreport();void generateinitialpopulation( ) //种群初始化{int i,j;for (i=0;i<popsize; i++){for(j=0;j<chromlength;j++){population[i].chrom[j]=(rand()%40<20)?'0':'1';}population[i].chrom[chromlength]='\0';}}void generatenextpopulation() //生成下一代{selectoperator();crossoveroperator();mutationoperator();}void evaluatepopulation() //评价个体,求最佳个体{calculateobjectvalue();calculatefitnessvalue();findbestandworstindividual();}long decodechromosome(char *string ,int point,int length) //给染色体解码{int i;long decimal=0;char*pointer;for(i=0,pointer=string+point;i<length;i++,pointer++)if(*pointer-'0'){decimal +=(long)pow(2,i);}return (decimal);}void calculateobjectvalue() //计算函数值{int i;long temp1,temp2;double x1,x2;for (i=0; i<popsize; i++){temp1=decodechromosome(population[i].chrom,0,length1);temp2=decodechromosome(population[i].chrom,length1,length2);x1=(max_x1-min_x1)*temp1/(1024*1024-1)+min_x1;x2=(max_x2-min_x2)*temp2/(1024*1024-1)+min_x2;//-----------函数population[i].value=x1*x1+sin(x1*x2)-x2*x2;//-----------}}void calculatefitnessvalue()//计算适应度{int i;double temp;for(i=0;i<popsize;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<cmax){temp=cmax-population[i].value;}else{ temp=0.0;}}population[i].fitness=temp;}}void findbestandworstindividual( ) //求最佳个体和最差个体{int i;double sum=0.0;bestindividual=population[0];worstindividual=population[0];for (i=1;i<popsize; i++){if (population[i].fitness>bestindividual.fitness){bestindividual=population[i];best_index=i;}else if (population[i].fitness<worstindividual.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() //演示评价结果{if (bestindividual.fitness>currentbest.fitness){currentbest=population[best_index];}else{population[worst_index]=currentbest;}}void selectoperator() //比例选择算法{int i,index;double p,sum=0.0;double cfitness[POPSIZE];struct individual newpopulation[POPSIZE];for(i=0;i<popsize;i++){sum+=population[i].fitness;}for(i=0;i<popsize; i++){cfitness[i]=population[i].fitness/sum;}for(i=1;i<popsize; i++){cfitness[i]=cfitness[i-1]+cfitness[i];}for (i=0;i<popsize;i++){p=rand()%1000/1000.0;index=0;while (p>cfitness[index]){index++;}newpopulation[i]=population[index];}for(i=0;i<popsize; i++){population[i]=newpopulation[i];}}void crossoveroperator() //交叉算法{int i,j;int index[POPSIZE];int point,temp;double p;char ch;for (i=0;i<popsize;i++){index[i]=i;}for (i=0;i<popsize;i++){point=rand()%(popsize-i);temp=index[i];index[i]=index[point+i];index[point+i]=temp;}for (i=0;i<popsize-1;i+=2){p=rand()%1000/1000.0;if (p<pc){point=rand()%(chromlength-1)+1;for (j=point; j<chromlength;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() //变异操作{int i,j;double p;for (i=0;i<popsize;i++){for(j=0;j<chromlength;j++){p=rand()%1000/1000.0;if (p<pm){population[i].chrom[j]=(population[i].chrom[j]=='0')?'1':'0';}}}}void input() //数据输入{ //printf("初始化全局变量:\n");//printf(" 种群大小(50-500):");//scanf("%d", &popsize);popsize=200;if((popsize%2) != 0){//printf( " 种群大小已设置为偶数\n");popsize++;};//printf(" 最大世代数(100-300):");//scanf("%d", &maxgeneration);maxgeneration=200;//printf(" 交叉率(0.2-0.99):");//scanf("%f", &pc);pc=0.9;//printf(" 变异率(0.001-0.1):");//scanf("%f", &pm);pm=0.003;}void outputtextreport()//数据输出{int i;double sum;double average;sum=0.0;for(i=0;i<popsize;i++){sum+=population[i].value;}average=sum/popsize;printf("当前世代=%d\n当前世代平均函数值=%f\n当前世代最优函数值=%f\n",generation,average,population[best_index].value);}void main() //主函数{ int i;long temp1,temp2;double x1,x2;generation=0;input();generateinitialpopulation();evaluatepopulation();while(generation<maxgeneration){generation++;generatenextpopulation();evaluatepopulation();performevolution();outputtextreport();}printf("\n");printf(" 统计结果: ");printf("\n");//printf("最大函数值等于:%f\n",currentbest.fitness);printf("其染色体编码为:");for (i=0;i<chromlength;i++){printf("%c",currentbest.chrom[i]);}printf("\n");temp1=decodechromosome(currentbest.chrom,0,length1);temp2=decodechromosome(currentbest.chrom,length1,length2);x1=(max_x1-min_x1)*temp1/(1024*1024-1)+min_x1;x2=(max_x2-min_x2)*temp2/(1024*1024-1)+min_x2;printf("x=%lf,y=%lf\n",x1,x2);//-----------修改函数printf("最大值=%f\n",x1*x1+sin(x1*x2)-x2*x2);//-----------}。
以下是一个简单的遗传算法的C语言代码示例:c#include <stdio.h>#include <stdlib.h>#include <time.h>#include <math.h>#define POPULATION_SIZE 100#define GENE_LENGTH 10#define MAX_GENERATIONS 1000#define MUTATION_RATE 0.01#define CROSSOVER_RATE 0.8typedef struct Individual {char genes[GENE_LENGTH];double fitness;} Individual;double calculate_fitness(Individual* individual) {// 计算适应度函数,这里使用简单的二进制字符串中1的个数作为适应度 int count = 0;for (int i = 0; i < GENE_LENGTH; i++) {if (individual->genes[i] == '1') {count++;}}return count;}void initialize_population(Individual* population) {// 初始化种群for (int i = 0; i < POPULATION_SIZE; i++) {for (int j = 0; j < GENE_LENGTH; j++) {population[i].genes[j] = rand() % 2 ? '0' : '1';}population[i].fitness = calculate_fitness(&population[i]); }}void selection(Individual* population, Individual* parents) {// 选择操作,采用轮盘赌算法选择两个父代个体double total_fitness = 0;for (int i = 0; i < POPULATION_SIZE; i++) {total_fitness += population[i].fitness;}double rand1 = rand() / (double)RAND_MAX * total_fitness;double rand2 = rand() / (double)RAND_MAX * total_fitness;double cumulative_fitness = 0;int parent1_index = -1, parent2_index = -1;for (int i = 0; i < POPULATION_SIZE; i++) {cumulative_fitness += population[i].fitness;if (rand1 < cumulative_fitness && parent1_index == -1) {parent1_index = i;}if (rand2 < cumulative_fitness && parent2_index == -1) {parent2_index = i;}}parents[0] = population[parent1_index];parents[1] = population[parent2_index];}void crossover(Individual* parents, Individual* offspring) {// 交叉操作,采用单点交叉算法生成两个子代个体int crossover_point = rand() % GENE_LENGTH;for (int i = 0; i < crossover_point; i++) {offspring[0].genes[i] = parents[0].genes[i];offspring[1].genes[i] = parents[1].genes[i];}for (int i = crossover_point; i < GENE_LENGTH; i++) {offspring[0].genes[i] = parents[1].genes[i];offspring[1].genes[i] = parents[0].genes[i];}offspring[0].fitness = calculate_fitness(&offspring[0]);offspring[1].fitness = calculate_fitness(&offspring[1]);}void mutation(Individual* individual) {// 变异操作,以一定概率翻转基因位上的值for (int i = 0; i < GENE_LENGTH; i++) {if (rand() / (double)RAND_MAX < MUTATION_RATE) {individual->genes[i] = individual->genes[i] == '0' ? '1' : '0'; }}individual->fitness = calculate_fitness(individual);}void replace(Individual* population, Individual* offspring) {// 替换操作,将两个子代个体中适应度更高的一个替换掉种群中适应度最低的一个个体int worst_index = -1;double worst_fitness = INFINITY;for (int i = 0; i < POPULATION_SIZE; i++) {if (population[i].fitness < worst_fitness) {worst_index = i;worst_fitness = population[i].fitness;}}if (offspring[0].fitness > worst_fitness || offspring[1].fitness > worst_fitness) {if (offspring[0].fitness > offspring[1].fitness) {population[worst_index] = offspring[0];} else {population[worst_index] = offspring[1];}}}。
遗传算法java代码遗传算法(Genetic Algorithm)是一种基于生物进化的启发式算法,通过模拟自然选择、交叉和突变等基因操作来优化问题的解。
以下是一个基于Java的遗传算法示例代码:```javaimport java.util.ArrayList;import java.util.List;import java.util.Random;//假设我们要求解的问题是求一个二进制序列的最大值,这个序列的长度为10public class GeneticAlgorithm//染色体长度private static final int CHROMOSOME_LENGTH = 10;//种群大小private static final int POPULATION_SIZE = 100;//迭代次数private static final int MAX_GENERATIONS = 100;//交叉概率private static final double CROSSOVER_RATE = 0.8;//变异概率private static final double MUTATION_RATE = 0.1; //随机数生成器private static final Random RANDOM = new Random(; //个体类private static class Individual//染色体private int[] chromosome;//适应度private double fitness;public Individuachromosome = new int[CHROMOSOME_LENGTH];fitness = 0.0;}//初始化染色体public void initializeChromosomfor (int i = 0; i < CHROMOSOME_LENGTH; i++) chromosome[i] = RANDOM.nextInt(2);}}//计算个体的适应度public void calculateFitnesint decimalValue = 0;for (int i = CHROMOSOME_LENGTH - 1; i >= 0; i--) decimalValue += chromosome[i] * Math.pow(2, CHROMOSOME_LENGTH - i - 1);}fitness = decimalValue;}//获取个体的适应度public double getFitnesreturn fitness;}//获取染色体public int[] getChromosomreturn chromosome;}//设置染色体public void setChromosome(int[] chromosome)this.chromosome = chromosome;}}//生成初始种群private static List<Individual> createInitialPopulatioList<Individual> population = new ArrayList<>(;for (int i = 0; i < POPULATION_SIZE; i++)Individual individual = new Individual(;individual.initializeChromosome(;population.add(individual);}return population;}//选择父母个体private static Individual selectParent(List<Individual> population)double sumFitness = 0.0;for (Individual individual : population)sumFitness += individual.getFitness(;}double randomFitness = RANDOM.nextDouble( * sumFitness;double cumulativeFitness = 0.0;for (Individual individual : population)cumulativeFitness += individual.getFitness(;if (cumulativeFitness > randomFitness)return individual;}}return population.get(0);}//交叉操作private static Individual crossover(Individual parent1, Individual parent2)Individual offspring = new Individual(;int[] parent1Chromosome = parent1.getChromosome(;int[] parent2Chromosome = parent2.getChromosome(;int crossoverPoint = RANDOM.nextInt(CHROMOSOME_LENGTH - 1) + 1;int[] offspringChromosome = new int[CHROMOSOME_LENGTH];System.arraycopy(parent1Chromosome, 0, offspringChromosome, 0, crossoverPoint);System.arraycopy(parent2Chromosome, crossoverPoint, offspringChromosome, crossoverPoint, CHROMOSOME_LENGTH - crossoverPoint);offspring.setChromosome(offspringChromosome);return offspring;}//变异操作private static void mutate(Individual individual)int[] chromosome = individual.getChromosome(;for (int i = 0; i < CHROMOSOME_LENGTH; i++)if (RANDOM.nextDouble( < MUTATION_RATE)chromosome[i] = chromosome[i] == 0 ? 1 : 0;}}individual.setChromosome(chromosome);}//遗传算法主函数public static void main(String[] args)List<Individual> population = createInitialPopulation(;for (int generation = 0; generation < MAX_GENERATIONS; generation++)for (Individual individual : population)individual.calculateFitness(;}Individual bestIndividual = population.get(0);for (Individual individual : population)if (individual.getFitness( > bestIndividual.getFitness() bestIndividual = individual;}}System.out.println("Generation: " + generation + " Best Individual: " + bestIndividual.getFitness();List<Individual> newPopulation = new ArrayList<>(;while (newPopulation.size( < POPULATION_SIZE)Individual parent1 = selectParent(population);Individual parent2 = selectParent(population);Individual offspring = crossover(parent1, parent2);mutate(offspring);newPopulation.add(offspring);}population = newPopulation;}}```以上示例代码实现了一个简单的二进制序列的最大化遗传算法。
Python遗传算法代码概述遗传算法是一种用于解决优化问题的算法,它模拟了生物进化的过程,通过选择、交叉和变异等操作来逐步优化解的质量。
Python作为一种简单易学的编程语言,非常适合用于实现遗传算法。
在本文中,我们将介绍如何使用Python编写遗传算法的代码,并通过实例演示其应用。
具体而言,我们将通过一个二进制字符串的优化问题来讲解遗传算法的实现过程。
问题描述假设我们有一个由0和1组成的二进制字符串,长度为N。
我们的目标是找到一个最优的二进制字符串,使得其中1的个数最多。
算法思想遗传算法是基于自然进化的思想,模拟了物种进化的过程。
它通过选择、交叉和变异等操作来逐步优化解的质量。
具体而言,遗传算法包括以下几个关键步骤: 1. 初始化种群:随机生成一定数量的二进制字符串,作为初始种群。
2. 计算适应度:针对每个个体,计算其适应度值,即1的个数。
3. 选择操作:根据适应度值选取优秀的个体,用于产生下一代。
常用的选择策略有轮盘赌选择、锦标赛选择等。
4. 交叉操作:选取一对个体,按照一定的规则进行基因交叉,生成新个体。
常见的交叉方式有单点交叉、多点交叉等。
5. 变异操作:随机选取一个个体的某个基因位,进行基因突变,生成具有变异基因的个体。
6. 产生下一代:根据选择、交叉和变异的操作,生成下一代种群。
7. 重复执行:重复执行上述步骤,直到满足终止条件。
代码实现下面是使用Python编写的遗传算法代码:import random# 定义问题相关的参数N = 20 # 二进制串的长度POP_SIZE = 50 # 种群大小GENERATIONS = 100 # 迭代代数SELECT_RATE = 0.2 # 选择概率CROSS_RATE = 0.8 # 交叉概率MUTATE_RATE = 0.01 # 变异概率# 生成初始种群def generate_population(pop_size):return [random.choices([0, 1], k=N) for _ in range(pop_size)]# 计算个体的适应度def fitness(individual):return sum(individual)# 选择操作def select(population, select_rate):fitness_values = [fitness(individual) for individual in population]total_fitness = sum(fitness_values)probabilities = [fitness_value / total_fitness for fitness_value in fitnes s_values]selected_population = random.choices(population, probabilities, k=int(pop_ size * select_rate))return selected_population# 交叉操作def crossover(parent_a, parent_b):cross_point = random.randint(0, N-1)child_a = parent_a[:cross_point] + parent_b[cross_point:]child_b = parent_b[:cross_point] + parent_a[cross_point:]return child_a, child_b# 变异操作def mutate(individual, mutate_rate):mutated_individual = individual.copy()for i in range(N):if random.random() < mutate_rate:mutated_individual[i] = 1 - mutated_individual[i]return mutated_individual# 产生下一代种群def generate_next_population(population, select_rate, cross_rate, mutate_rate): selected_population = select(population, select_rate)next_population = selected_population.copy()while len(next_population) < len(population):parent_a = random.choice(selected_population)parent_b = random.choice(selected_population)if random.random() < cross_rate:child_a, child_b = crossover(parent_a, parent_b)else:child_a, child_b = parent_a, parent_bchild_a = mutate(child_a, mutate_rate)child_b = mutate(child_b, mutate_rate)next_population.append(child_a)next_population.append(child_b)return next_population# 主函数def main():population = generate_population(POP_SIZE)for generation in range(GENERATIONS):population = generate_next_population(population, SELECT_RATE, CROSS_R ATE, MUTATE_RATE)best_individual = max(population, key=fitness)print(f"Generation: {generation}, Best Individual: {best_individual}, Fitness: {fitness(best_individual)}")if __name__ == "__main__":main()实例演示假设我们将二进制串的长度设为20,种群大小为50,迭代代数为100,选择概率为0.2,交叉概率为0.8,变异概率为0.01。
R课程遗传算法实验报告及源代码1. 简介本实验报告旨在介绍使用遗传算法解决问题的过程和实现源代码。
遗传算法是一种模拟自然进化过程的优化算法,它通过模拟遗传、变异和选择等操作来寻找问题的最优解。
2. 实验目标本实验的目标是使用遗传算法解决某个特定问题,并通过实现源代码来验证算法的有效性。
具体问题的背景和目标将在下一章节进行介绍。
3. 实验过程本实验包括以下步骤:3.1 确定问题和目标在本实验中,我们选择了一个具体的问题,并明确了优化的目标。
该问题将在下一章节进行详细描述。
3.2 设计遗传算法根据问题的特点和目标,我们设计了适当的遗传算法。
该算法包括基因表示、交叉和变异操作等关键步骤。
具体算法细节将在下一章节进行说明。
3.3 实现源代码基于所设计的遗传算法,我们使用R语言实现了相关的源代码。
代码将在附件中提供。
3.4 运行实验我们使用实现的源代码进行实验,并记录实验结果。
所得结果将在下一章节进行展示和分析。
3.5 结果分析和讨论根据实验结果,我们对所得结果进行了分析和讨论。
通过比较不同参数设置和算法策略的实验结果,我们评估了算法的性能和有效性。
具体分析和讨论内容将在下一章节进行描述。
4. 具体问题描述和实验结果本章节将详细描述选择的问题和实验结果。
由于篇幅限制,具体内容将在实际报告中提供。
5. 结论通过本次实验,我们成功使用遗传算法解决了特定问题,并验证了算法的有效性。
实验结果表明,遗传算法在优化问题中具有较好的性能和适用性。
6. 参考文献在实验报告中会引用相关的参考文献,供读者进一步了解该问题和遗传算法的相关理论。
// 在这里插入实现的R源代码。
附页:一.遗传算法源程序:clc;clear;population;%评价目标函数值for uim=1:popsizevector=population(uim,:);obj(uim)=hanshu(hromlength,vector,phen); end%obj%min(obj)clear uim;objmin=min(obj);for sequ=1:popsizeif obj(sequ)==objminopti=population(sequ,:);endendclear sequ;fmax=22000;%==for gen=1:maxgen%选择操作%将求最小值的函数转化为适应度函数for indivi=1:popsizeobj1(indivi)=1/obj(indivi);endclear indivi;%适应度函数累加总合total=0;for indivi=1:popsizetotal=total+obj1(indivi);endclear indivi;%每条染色体被选中的几率for indivi=1:popsizefitness1(indivi)=obj1(indivi)/total;endclear indivi;%各条染色体被选中的范围for indivi=1:popsizefitness(indivi)=0;for j=1:indivifitness(indivi)=fitness(indivi)+fitness1(j);endendclear j;fitness;%选择适应度高的个体for ranseti=1:popsizeran=rand;while (ran>1||ran<0)ran=rand;endran;if ran<=fitness(1)newpopulation(ranseti,:)=population(1,:);elsefor fet=2:popsizeif (ran>fitness(fet-1))&&(ran<=fitness(fet))newpopulation(ranseti,:)=population(fet,:);endendendendclear ran;newpopulation;%交叉for int=1:2:popsize-1popmoth=newpopulation(int,:);popfath=newpopulation(int+1,:);popcross(int,:)=popmoth;popcross(int+1,:)=popfath;randnum=rand;if(randnum< P>cpoint1=round(rand*hromlength);cpoint2=round(rand*hromlength);while (cpoint2==cpoint1)cpoint2=round(rand*hromlength);endif cpoint1>cpoint2tem=cpoint1;cpoint1=cpoint2;cpoint2=tem;endcpoint1;cpoint2;for term=cpoint1+1:cpoint2for ss=1:hromlengthif popcross(int,ss)==popfath(term)tem1=popcross(int,ss);popcross(int,ss)=popcross(int,term);popcross(int,term)=tem1;endendclear tem1;endfor term=cpoint1+1:cpoint2for ss=1:hromlengthif popcross(int+1,ss)==popmoth(term)tem1=popcross(int+1,ss);popcross(int+1,ss)=popcross(int+1,term);popcross(int+1,term)=tem1;endendclear tem1;endendclear term;endclear randnum;popcross;%变异操作newpop=popcross;for int=1:popsizerandnum=rand;if randnumcpoint12=round(rand*hromlength);cpoint22=round(rand*hromlength);if (cpoint12==0)cpoint12=1;endif (cpoint22==0)cpoint22=1;endwhile (cpoint22==cpoint12)cpoint22=round(rand*hromlength);if cpoint22==0;cpoint22=1;endendtemp=newpop(int,cpoint12);newpop(int,cpoint12)=newpop(int,cpoint22);newpop(int,cpoint22)=temp;endendnewpop;clear cpoint12;clear cpoint22;clear randnum;clear int;for ium=1:popsizevector1=newpop(ium,:);obj1(ium)=hanshu(hromlength,vector1,phen);endclear ium;obj1max=max(obj1);for ar=1:popsizeif obj1(ar)==obj1maxnewpop(ar,:)=opti;endend%遗传操作结束二.粒子群算法源程序:%------初始格式化-------------------------------------------------- clear all;clc;format long;%------给定初始化条件---------------------------------------------- c1=1.4962;%学习因子1c2=1.4962;%学习因子2w=0.7298;%惯性权重MaxDT=100;%最大迭代次数D=2;%搜索空间维数(未知数个数)N=40;%初始化群体个体数目eps=10^(-6);%设置精度(在已知最小值时候用)%------初始化种群的个体(可以在这里限定位置和速度的范围)------------ for i=1:Nfor j=1:Dx(i,j)=randn;%随机初始化位置v(i,j)=randn;%随机初始化速度endend%------先计算各个粒子的适应度,并初始化Pi和Pg---------------------- for i=1:Np(i)=fitness(x(i,:),D);y(i,:)=x(i,:);endpg=x(1,:);%Pg为全局最优for i=2:Nif fitness(x(i,:),D)<FITNESS(pg,D)pg=x(i,:);endend%------进入主要循环,按照公式依次迭代,直到满足精度要求------------ for t=1:MaxDTtfor i=1:Nv(i,:)=w*v(i,:)+c1*rand*(y(i,:)-x(i,:))+c2*rand*(pg-x(i,:)); x(i,:)=x(i,:)+v(i,:);if fitness(x(i,:),D)<p(i)p(i)=fitness(x(i,:),D);y(i,:)=x(i,:);endif p(i)<FITNESS(pg,D)pg=y(i,:);endendPbest(t)=fitness(pg,D);end%------进入主要循环,按照公式依次迭代,直到满足精度要求------------ for t=1:MaxDTfor i=1:Nv(i,:)=w*v(i,:)+c1*rand*(y(i,:)-x(i,:))+c2*rand*(pg-x(i,:));x(i,:)=x(i,:)+v(i,:);if fitness(x(i,:),D)<p(i)p(i)=fitness(x(i,:),D);y(i,:)=x(i,:);endif p(i)<FITNESS(pg,D)pg=y(i,:);endendPbest(t)=fitness(pg,D);end%------最后给出计算结果disp('*************************************************************') disp('函数的全局最优位置为:')Solution=pg'disp('最后得到的优化极值为:')Result=fitness(pg,D)disp('*************************************************************') [X,Y]=meshgrid(-500:2:500);Z=X.*sin(sqrt(X))+Y.*(sin(sqrt(Y)));hold oncontour(X,Y,Z)plot(x(:,1),x(:,2),'*');hold off标准文档实用文案。
一.问题描述:
在某一区域内有n 个客户,拟建一个物流中心,已知客户j 地址坐标为),(i i y x 。
确定物流中心的地址坐标),(y x ,使得该物流中心到几个客户之间的距离最短。
假设:简单的用两点之间的距离代替运输距离。
目标函数:
22)()(min i i y Y x X z -+-=
约束条件:
}
8,7,6,5,4,3,2,1,0{}8,7,6,5,4,3,2,1,0{X ∈∈Y 假设某一区域内有 5 个客户,其位置坐标如下表所示,
(1)变量:
C :是一个1*6数组,每个数组里面是一个6位二进制数,它是遗传算法中的染色体。
new_c:每一轮的新变量c 。
first_c:初始群体矩阵。
sur_value :个体适应值的概率值,为0-1之间的数,所有概率值和为1。
survived :经过选择运算后产生的个体基因型组合。
intersect_c :经过交叉运算后产生的个体基因型组合。
mutation_c :经过变异运算后产生的个体基因型组合。
f :最后计算得到的最大值
(2)程序里面的方程
function out = value_function( ci ):价值函数(自适应度函数)。
function [ sur_value ] = calc_value( c ):计算群体中每一个个体的适应度的值
function survived = surviver( sur_value ):利用概率选择函数
function [ intersect_c ] = intersect( new_c ):交叉运算
function [ mutation_c ,mutation_value] = mutation( intersect_c ):变异运算
(1)遗传算法主程序
%遗传算法的主程序
%初始群体的产生,本例中,群体规模大小取为6,即由6个个体组成,每个个体随机产生。
c = rand(6,6);%产生随机群体,c表示个体变量。
%第一个6表示个体个体,第二个6表示基因型由6位无符号二进制数组成
c(c>0.5) = 1;
c(c<0.5) = 0;
%显示初始群体
first_c = c;
points = [1,5;2,8;5,1;7,6;8,3];
%目的点
%一轮算法包括选择,交叉,变异,变异完成后产生新的个体,作为子代群体进行下一轮进化。
一共设置1000次进化
for n = 1:1000%设置循环次数
sur_value = calc_value(c,points);
survived = surviver(sur_value);
new_c = zeros(6,6);
for ii =1:6
new_c(ii,:) = c(survived(ii),:);
end
intersect_c = intersect(new_c);%交叉个体
mutation_c = mutation( intersect_c );%变异个体,作为子代群体
c = mutation_c;%子代群体作为新一轮的个体,继续选择,交叉,变异
end
f=0;
for jj=1:6
b = value_function(new_c(jj,:),points);
if b>f
f=b;
end
end
(2)适应度函数计算:适应度函数选择为目标函数的倒数
function distance = value_function( ci,points )
%遗传算法的价值函数,同时也可以将此目标函数值作为个体的适应度。
x = 4*ci(1)+2*ci(2)+1*ci(3)+1;
y = 4*ci(4)+2*ci(5)+1*ci(6)+1;
distance = 0;
for ii=1:length(points)
distance = distance +
((x-points(ii,1))^(2)+(y-points(ii,2))^(2))^(1/2);
end
end
function [ sur_value ] = calc_value( c,points )
%计算群体中每一个个体的适应度的值
value = zeros(1,6);
for ii = 1:6 %对于第1到第6个个体
value(ii) = 1 / value_function(c(ii,:),points);%计算每个个体的适应度值end
sur_value = value ./ sum(value);%将适应度值归一化,即每个个
%体被遗传到下一代群体中的概率
end
(3)选择计算
function survived = surviver( sur_value )
%选择个体,采用与适应度成正比的概率来确定各个个体复制到下一代群体中
survived = ones(1,6);
for ii = 1:6
random = rand(1)%随机产生一个0到1的数
%判断该随机数出现在哪一个概率区间内,以此来判断哪个个体被选中
sur_v_a=0;
%设置最后结果的输出
for jj = 1:6
sur_v_a=sur_v_a+sur_value(jj);
if random <sur_v_a
survived(ii) = jj;
break;
end
end
end
end
(4)交叉运算
随机设置交叉点
function [ r ] = random5( )
%随机设置交叉点位置,一共有5个交叉点位置。
6个个体共需3次交叉
r = rand(1)*5;
r = floor(r)+1;
end
function [ intersect_c ] = intersect( new_c )
%j进行交叉运算:以某一概率相互交换某两个个体之间的部分染色体
% 此处显示详细说明
intersect_c =zeros(6,6);
for ii = 1:3
r5 = random5();
intersect_c(ii*2-1,1:r5) = new_c(ii*2-1,1:r5);
intersect_c(ii*2-1,r5+1:6) = new_c(ii*2,r5+1:6);
intersect_c(ii*2,1:r5) =new_c(ii*2,1:r5);
intersect_c(ii*2,r5+1:6) = new_c(ii*2-1,r5+1:6);
end
end
(5)变异运算,变异概率为0.05
function [ mutation_c ,mutation_value] = mutation( intersect_c ) %变异运算:对个体的某一个或某一些基因座上的基因值按某一较小的概率进行改变
%
mutation_c = intersect_c;
mutation_value = zeros(2,36);
count=1;
for ii=1:6
for jj=1:6
r = rand(1);
if r<0.05
mutation_c(ii,jj)=1-mutation_c(ii,jj);
mutation_value(1,count)=ii;
mutation_value(2,count)=jj;
count=count+1;
end
end
end
end
经过1000次迭代后,产生的结果为:C的值。
对应的最优解为f的值。