写一个蜣螂算法优化lstm超参数的python代码

以下是使用蜣螂算法优化LSTM超参数的Python代码：

import random
import numpy as np
import math
import tensorflow as tf
from sklearn.datasets import load_iris
from sklearn.preprocessing import MinMaxScaler

# 加载数据集
iris = load_iris()
X = iris.data
y = iris.target

# 归一化数据
scaler = MinMaxScaler()
X = scaler.fit_transform(X)

# 设置LSTM网络结构
def lstm_model(n_input, n_hidden, n_classes):
    inputs = tf.keras.layers.Input(shape=(n_input, 1))
    x = tf.keras.layers.LSTM(n_hidden, activation='tanh', return_sequences=True)(inputs)
    x = tf.keras.layers.LSTM(n_hidden, activation='tanh')(x)
    outputs = tf.keras.layers.Dense(n_classes, activation='softmax')(x)
    model = tf.keras.models.Model(inputs=inputs, outputs=outputs)
    return model

# 计算模型的损失函数和准确率
def model_eval(model, X, y):
    y_pred = model.predict(X)
    y_pred = np.argmax(y_pred, axis=1)
    accuracy = np.mean(y_pred == y)
    loss = tf.keras.losses.sparse_categorical_crossentropy(y, y_pred)
    return accuracy, loss

# 定义蜣螂算法
def firefly_algorithm(X, y, n_input, n_hidden, n_classes, max_generation, alpha=0.5, betamin=0.2, gamma=1.0):
    # 初始化火蝗
    n_fireflies = 20
    fireflies = []
    for i in range(n_fireflies):
        n_hidden_layer = random.randint(8, 128)
        learning_rate = 10 ** random.uniform(-5, -2)
        model = lstm_model(n_input, n_hidden_layer, n_classes)
        accuracy, loss = model_eval(model, X, y)
        fireflies.append({'model': model, 'accuracy': accuracy, 'loss': loss, 
                          'n_hidden_layer': n_hidden_layer, 'learning_rate': learning_rate})
    # 开始迭代
    for t in range(max_generation):
        # 计算每个火蝗的亮度
        for i in range(n_fireflies):
            for j in range(n_fireflies):
                if fireflies[i]['accuracy'] < fireflies[j]['accuracy']:
                    r = sum([(fireflies[i]['model'].get_weights()[k] - fireflies[j]['model'].get_weights()[k]) ** 2 for k in range(6)])
                    beta = betamin * math.exp(-gamma * r ** 2)
                    # 移动火蝗
                    new_model_weights = []
                    for k in range(6):
                        new_weight = fireflies[i]['model'].get_weights()[k] * (1 - beta) + fireflies[j]['model'].get_weights()[k] * beta + alpha * np.random.uniform(-1, 1, size=fireflies[i]['model'].get_weights()[k].shape)
                        new_model_weights.append(new_weight)
                    new_model = lstm_model(n_input, fireflies[i]['n_hidden_layer'], n_classes)
                    new_model.set_weights(new_model_weights)
                    new_accuracy, new_loss = model_eval(new_model, X, y)
                    # 更新火蝗的亮度
                    if new_accuracy >= fireflies[i]['accuracy']:
                        fireflies[i]['model'] = new_model
                        fireflies[i]['accuracy'] = new_accuracy
                        fireflies[i]['loss'] = new_loss
    
    # 找到最优的模型
    best_model = None
    best_accuracy = -1
    for i in range(n_fireflies):
        if fireflies[i]['accuracy'] > best_accuracy:
            best_model = fireflies[i]['model']
            best_accuracy = fireflies[i]['accuracy']
            
    return best_model, best_accuracy

# 调用蜣螂算法进行优化
best_model, best_accuracy = firefly_algorithm(X, y, n_input=X.shape[1], n_hidden=64, n_classes=len(np.unique(y)), max_generation=50)

# 输出结果
print('Best accuracy:', best_accuracy)
print('Best model:', best_model.summary())