我有使用ASD仪器测量的真实不同草的光谱反射率,如何利用遗传算法优化oif指数进行高光谱波段选择?请帮我写出具体需要的文件以及其格式,并写出具体实现代码,并注释所有代码
时间: 2023-06-13 17:06:24 浏览: 140
首先需要准备的文件有:
1. 光谱反射率数据文件,格式为:每行为一个波段,每列为不同草的反射率值,用制表符分隔。
2. 遗传算法参数配置文件,包括种群大小、迭代次数、交叉概率、变异概率等。
3. 遗传算法适应度函数代码文件,用于计算每个个体的适应度值。
4. 遗传算法主程序代码文件,包括种群初始化、适应度计算、选择、交叉、变异等操作。
以下是一个示例代码,供参考:
首先是光谱反射率数据文件的读取:
```python
import numpy as np
# 读取光谱反射率数据文件
def read_data_file(file_path):
with open(file_path, 'r') as f:
lines = f.readlines()
data = []
for line in lines:
line = line.strip().split('\t')
line = [float(x) for x in line]
data.append(line)
return np.array(data)
```
接下来是遗传算法参数配置文件的读取:
```python
# 读取遗传算法参数配置文件
def read_config_file(file_path):
with open(file_path, 'r') as f:
lines = f.readlines()
config = {}
for line in lines:
line = line.strip().split('=')
key = line[0].strip()
value = line[1].strip()
config[key] = value
return config
```
然后是遗传算法适应度函数代码,这里可以使用OIF指数作为适应度函数:
```python
# 计算OIF指数
def calculate_oif(data, wavelengths):
x = wavelengths[np.newaxis, :]
y = data.T
y_mean = np.mean(y, axis=0, keepdims=True)
y_norm = y - y_mean
cov = (1 / (y.shape[0] - 1)) * np.dot(y_norm.T, y_norm)
invcov = np.linalg.inv(cov)
oif = np.sum(np.dot(np.dot(x, invcov), x.T), axis=1)
return oif
# 计算适应度值
def calculate_fitness(data, wavelengths, selected_bands):
selected_data = data[selected_bands, :]
oif = calculate_oif(selected_data, wavelengths[selected_bands])
fitness = np.mean(oif)
return fitness
```
最后是遗传算法主程序代码,包括种群初始化、适应度计算、选择、交叉、变异等操作:
```python
import random
# 初始化种群
def init_population(pop_size, num_bands):
population = []
for i in range(pop_size):
individual = [0] * num_bands
for j in range(num_bands):
individual[j] = random.randint(0, 1)
population.append(individual)
return population
# 选择操作
def selection(population, fitness):
fitness_sum = np.sum(fitness)
prob = fitness / fitness_sum
cum_prob = np.cumsum(prob)
new_population = []
for i in range(len(population)):
r = random.random()
for j in range(len(population)):
if r <= cum_prob[j]:
new_population.append(population[j])
break
return new_population
# 交叉操作
def crossover(population, crossover_prob):
new_population = []
for i in range(0, len(population), 2):
parent1 = population[i]
parent2 = population[i+1]
if random.random() < crossover_prob:
crossover_point = random.randint(1, len(parent1)-1)
child1 = parent1[:crossover_point] + parent2[crossover_point:]
child2 = parent2[:crossover_point] + parent1[crossover_point:]
else:
child1 = parent1[:]
child2 = parent2[:]
new_population.append(child1)
new_population.append(child2)
return new_population
# 变异操作
def mutation(population, mutation_prob):
for i in range(len(population)):
for j in range(len(population[i])):
if random.random() < mutation_prob:
population[i][j] = 1 - population[i][j]
return population
# 遗传算法主程序
def genetic_algorithm(data, wavelengths, config):
# 读取配置文件
pop_size = int(config['pop_size'])
num_bands = data.shape[0]
max_iter = int(config['max_iter'])
crossover_prob = float(config['crossover_prob'])
mutation_prob = float(config['mutation_prob'])
# 初始化种群
population = init_population(pop_size, num_bands)
# 迭代优化
for i in range(max_iter):
# 计算适应度值
fitness = []
for j in range(pop_size):
selected_bands = [k for k in range(num_bands) if population[j][k] == 1]
fitness.append(calculate_fitness(data, wavelengths, selected_bands))
# 选择操作
population = selection(population, fitness)
# 交叉操作
population = crossover(population, crossover_prob)
# 变异操作
population = mutation(population, mutation_prob)
# 获得最优解
fitness = []
for j in range(pop_size):
selected_bands = [k for k in range(num_bands) if population[j][k] == 1]
fitness.append(calculate_fitness(data, wavelengths, selected_bands))
best_individual = population[np.argmax(fitness)]
selected_bands = [k for k in range(num_bands) if best_individual[k] == 1]
return selected_bands
```
以上是一个简单的高光谱波段选择的遗传算法实现,具体的实现过程中需要根据实际情况进行调整和优化。
阅读全文