2024 年高教社杯全国大学生数学建模竞赛B题第三问详细解题思路（终版）

示例代码：

import numpy as np
import pandas as pd# 参数设定
params = {'m': 8,  # 零配件数量'n': 2,  # 半成品数量'p': [0.10, 0.10, 0.10, 0.10, 0.10, 0.10, 0.10, 0.10],  # 零配件次品率'c': [2, 8, 12, 2, 8, 12, 8, 12],  # 购买单价'd': [1, 1, 2, 1, 1, 2, 1, 2],  # 检测成本'a': [8, 8],  # 装配成本'pf': 0.10,  # 成品次品率's': 200,  # 市场售价'l': 40,  # 调换损失'r': 6  # 拆解费用
}# 决策变量
decisions = [0, 1]# 利润计算函数
def calculate_profit(D, C, R, params):cost_parts = sum(params['c'][i] + params['d'][i] * D[i] for i in range(params['m']))cost_subassemblies = sum(params['a'][j] + params['d'][j + params['m']] * C[j] for j in range(params['n']))revenue = params['s'] * (1 - params['pf'])cost_rework = params['r'] * R * params['pf']loss_replacement = params['l'] * params['pf']profit = revenue - cost_parts - cost_subassemblies - cost_rework - loss_replacementreturn profit# 遍历所有可能的决策组合
best_profit = -np.inf
best_decision = None
for D in itertools.product(decisions, repeat=params['m']):for C in itertools.product(decisions, repeat=params['n']):for R in decisions:profit = calculate_profit(D, C, R, params)if profit > best_profit:best_profit = profitbest_decision = (D, C, R)print(f"Best Decision: {best_decision}, Maximum Profit: {best_profit}")

可视化代码：

import numpy as np
import matplotlib.pyplot as plt
import itertools
import pandas as pd# 参数设定
params = {'m': 8,  # 零配件数量'n': 2,  # 半成品数量'p': [0.10, 0.10, 0.10, 0.10, 0.10, 0.10, 0.10, 0.10],  # 零配件次品率'c': [2, 8, 12, 2, 8, 12, 8, 12],  # 购买单价'd': [1, 1, 2, 1, 1, 2, 1, 2],  # 检测成本'a': [8, 8],  # 装配成本'pf': 0.10,  # 成品次品率's': 200,  # 市场售价'l': 40,  # 调换损失'r': 6  # 拆解费用
}# 决策变量
decisions = [0, 1]# 利润计算函数
def calculate_profit(D, C, R, params):cost_parts = sum(params['c'][i] + params['d'][i] * D[i] for i in range(params['m']))cost_subassemblies = sum(params['a'][j] + (params['d'][params['m'] + j] if j < len(params['d']) - params['m'] else 0) * C[j] for j in range(params['n']))revenue = params['s'] * (1 - params['pf'])cost_rework = params['r'] * R * params['pf']loss_replacement = params['l'] * params['pf']profit = revenue - cost_parts - cost_subassemblies - cost_rework - loss_replacementreturn profit# 遍历所有可能的决策组合
profits = []
decision_combinations = list(itertools.product(decisions, repeat=params['m'] + params['n'] + 1))
for combo in decision_combinations:D = combo[:params['m']]C = combo[params['m']:params['m'] + params['n']]R = combo[-1]profit = calculate_profit(D, C, R, params)profits.append(profit)# 转换为DataFrame以便可视化
df = pd.DataFrame(decision_combinations, columns=[f'D{i}' for i in range(params['m'])] + [f'C{j}' for j in range(params['n'])] + ['R'])
df['Profit'] = profits# 绘制决策变量对利润的影响图
plt.figure(figsize=(12, 8))
plt.bar(df.index, df['Profit'], color='skyblue')
plt.xlabel('Decision Combination Index')
plt.ylabel('Profit')
plt.title('Profit for Different Decision Combinations')
plt.xticks(rotation=90)
plt.show()# 敏感性分析图
sensitivity_params = ['c1', 'c2', 's', 'l', 'r']
for param in sensitivity_params:values = np.linspace(0.5, 1.5, 10) * params[param]profits_sensitivity = [calculate_profit(*[1]*params['m'], *[1]*params['n'], 1, {**params, param: value}) for value in values]plt.figure(figsize=(10, 6))plt.plot(values, profits_sensitivity, marker='o', label=f'Sensitivity to {param}')plt.xlabel(f'{param} Value')plt.ylabel('Profit')plt.title(f'Sensitivity Analysis for {param}')plt.legend()plt.grid(True)plt.show()