请用matlab代码解决算例
时间: 2024-10-21 18:11:44 浏览: 12
要使用MATLAB代码解决您提供的算例,我们需要编写一个遗传算法来优化B2C环境下生鲜农产品的物流配送路径。下面是一个简化版的MATLAB代码示例,用于解决这个问题:
```matlab
function main
% 参数设置
popSize = 60; % 种群大小
maxGen = 300; % 最大迭代次数
Pc = 0.5; % 交叉概率
Pm = 0.06; % 变异概率
Q = 100; % 配送车最大载重量 (kg)
deliveryCost = 1; % 单位距离配送成本 (元/km)
productPrice = 20; % 生鲜农产品单价 (元/kg)
T = 48; % 生鲜农产品保质期 (小时)
w1 = 30; % 早于期望收货时间的惩罚费用 (元/小时)
w2 = 40; % 晚于期望收货时间的惩罚费用 (元/小时)
% 初始化配送中心和顾客信息
centers = [6, 15; 14, 12; 4, 8]; % 配送中心坐标
customers = struct();
customers.A = readCustomers('A');
customers.B = readCustomers('B');
customers.C = readCustomers('C');
% 初始化种群
population = initPopulation(customers, popSize);
% 遗传算法主循环
for gen = 1:maxGen
% 计算适应度
fitness = calculateFitness(population, customers, centers, Q, deliveryCost, productPrice, T, w1, w2);
% 选择操作
selectedPop = selection(population, fitness);
% 交叉操作
crossedPop = crossover(selectedPop, Pc);
% 变异操作
mutatedPop = mutation(crossedPop, Pm);
% 更新种群
population = mutatedPop;
end
% 获取最佳个体
bestChromosome = population{find(fitness == max(fitness), 1)};
% 输出结果
displayResults(bestChromosome, customers, centers, Q, deliveryCost, productPrice, T, w1, w2);
end
function cust = readCustomers(center)
% 读取顾客信息
if strcmp(center, 'A')
cust = [
1, 10, 1, 10, 10, 12, 15, 18; % x, y, demand, ET', LT', ET, LT
2, 12, 15, 1, 10, 10, 12, 15;
3, 8, 6, 1, 10, 10, 12, 15;
4, 15, 18, 1, 10, 10, 12, 15;
5, 18, 15, 1, 10, 10, 12, 15;
6, 12, 8, 1, 10, 10, 12, 15;
7, 6, 12, 1, 10, 10, 12, 15;
8, 15, 6, 1, 10, 10, 12, 15;
9, 18, 12, 1, 10, 10, 12, 15
];
elseif strcmp(center, 'B')
cust = [
1, 10, 10, 1, 10, 10, 12, 15;
2, 12, 15, 1, 10, 10, 12, 15;
3, 8, 6, 1, 10, 10, 12, 15;
4, 15, 18, 1, 10, 10, 12, 15;
5, 18, 15, 1, 10, 10, 12, 15;
6, 12, 8, 1, 10, 10, 12, 15;
7, 6, 12, 1, 10, 10, 12, 15;
8, 15, 6, 1, 10, 10, 12, 15
];
else
cust = [
1, 10, 10, 1, 10, 10, 12, 15;
2, 12, 15, 1, 10, 10, 12, 15;
3, 8, 6, 1, 10, 10, 12, 15;
4, 15, 18, 1, 10, 10, 12, 15;
5, 18, 15, 1, 10, 10, 12, 15;
6, 12, 8, 1, 10, 10, 12, 15;
7, 6, 12, 1, 10, 10, 12, 15;
8, 15, 6, 1, 10, 10, 12, 15;
9, 18, 12, 1, 10, 10, 12, 15
];
end
end
function population = initPopulation(customers, popSize)
% 初始化种群
population = cell(1, popSize);
for i = 1:popSize
chromosome = [];
for center = fieldnames(customers)'
custList = randperm(size(customers.(center{:}), 1));
chromosome = [chromosome, custList];
end
population{i} = chromosome;
end
end
function fitness = calculateFitness(population, customers, centers, Q, deliveryCost, productPrice, T, w1, w2)
% 计算适应度
fitness = zeros(1, length(population));
for i = 1:length(population)
chromosome = population{i};
totalCost = 0;
customerIndex = 1;
for center = fieldnames(customers)'
custList = chromosome(customerIndex:customerIndex + size(customers.(center{:}), 1) - 1);
routes = createRoutes(custList, customers.(center{:}), centers(center), Q);
for j = 1:length(routes)
route = [centers(center); routes{j}];
cost = 0;
time = 0;
load = 0;
for k = 1:length(route)-1
dist = norm(route(k, :) - route(k+1, :));
time = time + dist / 15 + 10; % 速度15km/h,停留10分钟
load = load + customers.(center{:})(route(k+1, 1), 3);
if time < customers.(center{:})(route(k+1, 1), 4)
cost = cost + w1 * (customers.(center{:})(route(k+1, 1), 4) - time);
elseif time > customers.(center{:})(route(k+1, 1), 5)
cost = cost + w2 * (time - customers.(center{:})(route(k+1, 1), 5));
end
freshnessLoss = productPrice * customers.(center{:})(route(k+1, 1), 3) * (1 - exp(-time/T));
cost = cost + dist * deliveryCost + freshnessLoss;
end
totalCost = totalCost + cost;
end
customerIndex = customerIndex + size(customers.(center{:}), 1);
end
fitness(i) = 1 / totalCost; % 适应度定义为总成本的倒数
end
end
function selectedPop = selection(population, fitness)
% 选择操作
selectedPop = {};
totalFitness = sum(fitness);
probabilities = fitness / totalFitness;
for i = 1:length(population)
idx = find(rand <= cumsum(probabilities), 1);
selectedPop{end+1} = population{idx};
end
end
function crossedPop = crossover(selectedPop, Pc)
% 交叉操作
crossedPop = selectedPop;
for i = 1:2:length(selectedPop)-1
if rand < Pc
p1 = selectedPop{i};
p2 = selectedPop{i+1};
crossPoint1 = randi([1, length(p1)-1]);
crossPoint2 = randi([crossPoint1+1, length(p1)]);
child1 = [p1(1:crossPoint1), p2(crossPoint1+1:crossPoint2), p1(crossPoint2+1:end)];
child2 = [p2(1:crossPoint1), p1(crossPoint1+1:crossPoint2), p2(crossPoint2+1:end)];
crossedPop{i} = unique(child1);
crossedPop{i+1} = unique(child2);
end
end
end
function mutatedPop = mutation(crossedPop, Pm)
% 变异操作
mutatedPop = crossedPop;
for i = 1:length(crossedPop)
if rand < Pm
mutPoint = randi(length(crossedPop{i}));
newGene = randi(length(crossedPop{i}));
while newGene == crossedPop{i}(mutPoint)
newGene = randi(length(crossedPop{i}));
end
temp = crossedPop{i}(mutPoint);
crossedPop{i}(mutPoint) = crossedPop{i}(newGene);
crossedPop{i}(newGene) = temp;
end
end
end
function routes = createRoutes(custList, customers, center, Q)
% 创建配送路线
routes = {};
currentRoute = [];
currentLoad = 0;
for i = 1:length(custList)
if currentLoad + customers(custList(i), 3) <= Q
currentRoute = [currentRoute, custList(i)];
currentLoad = currentLoad + customers(custList(i), 3);
else
routes{end+1} = currentRoute;
currentRoute = custList(i);
currentLoad = customers(custList(i), 3);
end
end
if ~isempty(currentRoute)
routes{end+1} = currentRoute;
end
end
function displayResults(chromosome, customers, centers, Q, deliveryCost, productPrice, T, w1, w2)
% 显示结果
fprintf('Optimal Delivery Routes:\n');
customerIndex = 1;
for center = fieldnames(customers)'
custList = chromosome(customerIndex:customerIndex + size(customers.(center{:}), 1) - 1);
routes = createRoutes(custList, customers.(center{:}), centers(center), Q);
fprintf('Center %s:\n', center);
for j = 1:length(routes)
route = [centers(center); routes{j}];
fprintf(' Route %d: ', j);
for k = 1:length(route)
if k == 1
fprintf('%s -> ', num2str(center));
else
fprintf('%d -> ', route(k));
end
end
fprintf('%s\n', num2str(center));
end
customerIndex = customerIndex + size(customers.(center{:}), 1);
end
totalCost = 0;
for center = fieldnames(customers)'
custList = chromosome(customerIndex:customerIndex + size(customers.(center{:}), 1) - 1);
routes = createRoutes(custList, customers.(center{:}), centers(center), Q);
for j = 1:length(routes)
route = [centers(center); routes{j}];
cost = 0;
time = 0;
load = 0;
for k = 1:length(route)-1
dist = norm(route(k, :) - route(k+1, :));
time = time + dist / 15 + 10;
load = load + customers.(center{:})(route(k+1, 1), 3);
if time < customers.(center{:})(route(k+1, 1), 4)
cost = cost + w1 * (customers.(center{:})(route(k+1, 1), 4) - time);
elseif time > customers.(center{:})(route(k+1, 1), 5)
cost = cost + w2 * (time - customers.(center{:})(route(k+1, 1), 5));
end
freshnessLoss = productPrice * customers.(center{:})(route(k+1, 1), 3) * (1 - exp(-time/T));
cost = cost + dist * deliveryCost + freshnessLoss;
end
totalCost = totalCost + cost;
end
customerIndex = customerIndex + size(customers.(center{:}), 1);
end
fprintf('Total Cost: %.2f\n', totalCost);
end
```
### 说明
1. **参数设置**:设置了种群大小、最大迭代次数、交叉概率、变异概率等参数。
2. **初始化配送中心和顾客信息**:读取各配送中心及其负责的顾客信息。
3. **初始化种群**:随机生成初始种群。
4. **遗传算法主循环**:包括适应度计算、选择、交叉、变异等操作。
5. **输出结果**:显示最佳配送路径和总成本。
### 注意事项
- 顾客信息需要根据实际情况调整。
- 代码中的一些参数(如配送车速度、停留时间等)也需要根据实际情况调整。
- 代码中的一些细节(如交叉和变异操作)可以根据具体需求进一步优化。
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