class Network(object): def __init__(self, num_of_weights): # 随机产生w的初始值 # 为了保持程序每次运行结果的一致性, # 此处设置固定的随机数种子 np.random.seed(0) self.w = np.random.randn(num_of_weights, 1) self.b = 0. def forward(self, x): z = np.dot(x, self.w) + self.b return z
时间: 2023-06-02 22:04:24 浏览: 241
这是一个类,命名为Network。它有一个初始化函数__init__,传入一个参数num_of_weights。该函数是初始化类的方法,用于设置类的属性或者完成其他必要的初始化工作。在这个类中,初始化函数需要接收一个权重数目的参数。
相关问题
深度神经模糊随机森林python代码
### 回答1:
深度神经模糊随机森林(Deep Neural Fuzzy Random Forest,DNF-RF)是一种基于随机森林和模糊神经网络的组合模型。其Python代码如下:
1. 导入相关库
```python
import numpy as np
from sklearn.ensemble import RandomForestClassifier
from sklearn.metrics import accuracy_score
from sklearn.preprocessing import LabelEncoder
import skfuzzy as fuzz
from skfuzzy import control as ctrl
```
2. 定义DNF-RF类
```python
class DNF_RF:
def __init__(self, num_trees, num_variables, num_classes, num_fuzzy_sets):
self.num_trees = num_trees
self.num_variables = num_variables
self.num_classes = num_classes
self.num_fuzzy_sets = num_fuzzy_sets
self.trees = []
self.fuzzy_sets = []
self.classifiers = []
def fit(self, X, y):
# 训练随机森林
for i in range(self.num_trees):
tree = RandomForestClassifier(n_estimators=1, max_features=self.num_variables)
tree.fit(X, y)
self.trees.append(tree)
# 训练模糊神经网络
for i in range(self.num_classes):
fuzzy_sets = []
for j in range(self.num_variables):
fuzzy_set = ctrl.Antecedent(np.arange(X[:,j].min(), X[:,j].max()+1, 1), 'input'+str(j+1))
for k in range(self.num_fuzzy_sets):
fuzzy_set['fuzzy'+str(k+1)] = fuzz.trimf(fuzzy_set.universe, [X[:,j].min(), X[:,j].max(), (X[:,j].max()-X[:,j].min())/(self.num_fuzzy_sets-1)*k])
fuzzy_sets.append(fuzzy_set)
output = ctrl.Consequent(np.arange(self.num_classes), 'output')
for k in range(self.num_classes):
output['class'+str(k+1)] = fuzz.trimf(output.universe, [k-0.5, k, k+0.5])
rule_list = []
for m in range(self.num_fuzzy_sets):
for n in range(self.num_fuzzy_sets):
rule = []
for l in range(self.num_variables):
rule.append(fuzzy_sets[l]['fuzzy'+str(m+1)] & fuzzy_sets[l]['fuzzy'+str(n+1)])
rule_list.append(np.prod(rule))
rule_list = np.array(rule_list).reshape((self.num_fuzzy_sets**2, self.num_variables))
rule_list = rule_list / np.sum(rule_list, axis=1).reshape((self.num_fuzzy_sets**2, 1))
classifier = ctrl.ControlSystemAntecedent(rule_list)
classifier.add(output)
self.fuzzy_sets.append(fuzzy_sets)
self.classifiers.append(classifier)
def predict(self, X):
# 预测随机森林
y_pred = np.zeros((X.shape[0], self.num_trees))
for i in range(self.num_trees):
y_pred[:,i] = self.trees[i].predict(X)
y_pred_rf = np.apply_along_axis(lambda x: np.bincount(x).argmax(), axis=1, arr=y_pred)
# 预测模糊神经网络
y_pred_dnf = np.zeros((X.shape[0], self.num_classes))
for i in range(self.num_classes):
inputs = {}
for j in range(self.num_variables):
inputs['input'+str(j+1)] = X[:,j]
self.classifiers[i].evaluate(inputs=inputs, outputs=y_pred_dnf[:,i])
y_pred_dnf = np.argmax(y_pred_dnf, axis=1)
# 组合预测结果
y_pred = (y_pred_rf + y_pred_dnf) // 2
return y_pred
```
3. 使用示例
```python
# 加载数据
X = np.genfromtxt('data.csv', delimiter=',')[:,:-1]
y = np.genfromtxt('data.csv', delimiter=',', dtype=str)[:,-1]
le = LabelEncoder()
y = le.fit_transform(y)
# 训练模型
dnf_rf = DNF_RF(num_trees=10, num_variables=X.shape[1], num_classes=len(np.unique(y)), num_fuzzy_sets=3)
dnf_rf.fit(X, y)
# 预测样本
y_pred = dnf_rf.predict(X)
# 计算准确率
accuracy = accuracy_score(y, y_pred)
print('Accuracy:', accuracy)
```
### 回答2:
深度神经模糊随机森林(Deep Neural Fuzzy Random Forest,DNFRF)是一种结合了深度神经网络(Deep Neural Networks,DNN)和模糊随机森林(Fuzzy Random Forest,FRF)的算法。它能够有效地处理具有模糊性质的数据,并具备较强的分类和预测能力。
下面是一个使用Python实现DNFRF的简单示例代码:
```python
from sklearn.ensemble import RandomForestClassifier
from sklearn.neural_network import MLPClassifier
from sklearn.metrics import accuracy_score
# 导入数据集
# X是特征向量,y是目标变量
X, y = load_dataset()
# 创建DNFRF模型
# 使用3个随机森林分类器和一个深度神经网络分类器
rf1 = RandomForestClassifier(n_estimators=100)
rf2 = RandomForestClassifier(n_estimators=100)
rf3 = RandomForestClassifier(n_estimators=100)
dnn = MLPClassifier(hidden_layer_sizes=(100,))
# 训练DNFRF模型
rf1.fit(X, y)
rf2.fit(X, y)
rf3.fit(X, y)
dnn.fit(X, y)
# 预测结果
# 将3个随机森林的预测结果和深度神经网络的预测结果加权平均
rf1_pred = rf1.predict(X)
rf2_pred = rf2.predict(X)
rf3_pred = rf3.predict(X)
dnn_pred = dnn.predict(X)
# 对权重进行归一化
weights_sum = len(rf1_pred) + len(rf2_pred) + len(rf3_pred) + len(dnn_pred)
rf1_weight = len(rf1_pred) / weights_sum
rf2_weight = len(rf2_pred) / weights_sum
rf3_weight = len(rf3_pred) / weights_sum
dnn_weight = len(dnn_pred) / weights_sum
# 对预测结果进行加权平均
ensemble_pred = rf1_weight * rf1_pred + rf2_weight * rf2_pred + rf3_weight * rf3_pred + dnn_weight * dnn_pred
# 计算准确率
accuracy = accuracy_score(y, ensemble_pred)
print("准确率为:", accuracy)
```
在这个简单的示例代码中,我们使用`sklearn`库中的`RandomForestClassifier`实现了三个随机森林分类器,以及`MLPClassifier`实现了一个深度神经网络分类器。我们使用加载好的数据集`X`和`y`进行训练和预测,并将四个模型的预测结果进行加权平均得到最终的集成预测结果。最后,使用`accuracy_score`计算得到预测结果的准确率。
需要注意的是,这只是一个简单的示例代码,实际应用中还需要进行更多的数据预处理、参数调整和模型优化等工作。
### 回答3:
深度神经模糊随机森林(Deep Neural Fuzzy Random Forest)是一种结合了神经网络和随机森林的机器学习算法。以下是一个简单的深度神经模糊随机森林的 Python 代码示例:
```python
# 导入所需库
import numpy as np
from sklearn.ensemble import RandomForestClassifier
from keras.models import Sequential
from keras.layers import Dense
# 创建深度神经模糊随机森林类
class DeepNeuralFuzzyRandomForest(object):
def __init__(self, num_trees, num_neurons):
self.num_trees = num_trees
self.num_neurons = num_neurons
self.forest = []
def fit(self, x_train, y_train):
# 创建一组随机森林
for _ in range(self.num_trees):
# 创建深度神经模糊网络模型
model = Sequential()
model.add(Dense(self.num_neurons, input_dim=x_train.shape[1], activation='relu'))
model.add(Dense(self.num_neurons, activation='relu'))
model.add(Dense(1, activation='sigmoid'))
model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])
# 训练模型
model.fit(x_train, y_train, epochs=10, batch_size=32, verbose=0)
# 将训练好的模型添加到随机森林中
self.forest.append(model)
def predict(self, x_test):
# 对测试样本进行预测
predictions = np.zeros((x_test.shape[0],))
for model in self.forest:
pred = model.predict(x_test)
predictions += pred.flatten()
# 找到所有预测结果中的最大值,并根据阈值进行二分类
predictions /= len(self.forest)
predictions = (predictions > 0.5).astype(np.int)
return predictions
# 测试代码
# 创建随机样本数据
x_train = np.random.rand(100, 10)
y_train = np.random.randint(0, 2, size=(100,))
# 创建深度神经模糊随机森林模型
dnf_rf = DeepNeuralFuzzyRandomForest(num_trees=10, num_neurons=64)
# 拟合模型
dnf_rf.fit(x_train, y_train)
# 创建测试样本
x_test = np.random.rand(10, 10)
# 预测结果
predictions = dnf_rf.predict(x_test)
print(predictions)
```
这段代码演示了如何使用 Python 建立一个基本的深度神经模糊随机森林模型。首先,通过导入所需的库,包括 `numpy`、`sklearn` 和 `keras` 等。然后,创建一个名为 `DeepNeuralFuzzyRandomForest` 的类,其中包含模型的初始化、拟合和预测方法。在拟合方法中,使用神经网络模型对每个树进行训练,并将训练好的模型添加到随机森林中。在预测方法中,对测试样本进行预测,并根据阈值进行二分类。最后,通过创建随机样本数据、创建模型、拟合模型和预测结果等步骤对代码进行测试,并输出预测结果。
使用python创建一个使用归一化、Xavier初始化、正则化方法和MSGD的BP网络,该网络有8个输入1个输出1层隐藏层,要求分为两个模块(py文件),且一个是BP网络,另一个是主函数,在每句代码后添加注释;训练集数据存于xlsx表格前3000行中,测试集为之后的40行,且均为float类型,即训练模型时以3000行数据作为训练集,而之后也可以将40行的测试集数据输入模型中并正常运行出结果。并且能够输出各输入的权重。尝试在main模块中实现将训练后的BP网络模型输出为一个文件,绘制R2图来说明模型的拟合度,并且输出MAE、MSE、预测值和真实值之间的相对误差平均百分比,绘制测试集的各输入对应的实际输出和预测输出的拟合折线图,且R2图和折线图中使用的数据均为未变换数据。避免'float' object has no attribute 'exp'问题
很高兴帮助您解决这个问题!接下来我将为您提供一个实现上述要求的代码,包含BP网络和主函数两个模块。
首先,我们需要创建BP网络模块,命名为`bp_network.py`:
```python
import numpy as np
import openpyxl as opx
import os.path as osp
class BPNetwork:
def __init__(self, input_size, hidden_size, output_size):
# 初始化输入层、隐藏层和输出层大小
self.input_size = input_size
self.hidden_size = hidden_size
self.output_size = output_size
# 使用Xavier初始化权重和偏置
self.weight_ih = np.random.randn(hidden_size, input_size) * np.sqrt(2 / input_size)
self.bias_h = np.zeros((hidden_size, 1))
self.weight_ho = np.random.randn(output_size, hidden_size) * np.sqrt(2 / hidden_size)
self.bias_o = np.zeros((output_size, 1))
def train(self, x_train, y_train, learning_rate, num_epochs, batch_size, reg_lambda):
# 归一化训练数据
x_train_mean = np.mean(x_train, axis=0)
x_train_std = np.std(x_train, axis=0)
x_train_norm = (x_train - x_train_mean) / x_train_std
# 将训练数据分为mini-batches
num_batches = int(np.ceil(x_train_norm.shape[0] / batch_size))
batches_x = np.array_split(x_train_norm, num_batches)
batches_y = np.array_split(y_train, num_batches)
# 训练网络
for epoch in range(num_epochs):
for batch_x, batch_y in zip(batches_x, batches_y):
# 前向传播
hidden = self._sigmoid(np.dot(self.weight_ih, batch_x.T) + self.bias_h)
output = np.dot(self.weight_ho, hidden) + self.bias_o
# 计算损失
loss = 0.5 * np.mean((output - batch_y.T) ** 2) + 0.5 * reg_lambda * (
np.sum(self.weight_ih ** 2) + np.sum(self.weight_ho ** 2))
# 反向传播
d_output = output - batch_y.T
d_weight_ho = np.dot(d_output, hidden.T) / batch_size + reg_lambda * self.weight_ho
d_bias_o = np.mean(d_output, axis=1, keepdims=True)
d_hidden = np.dot(self.weight_ho.T, d_output) * self._sigmoid_derivative(hidden)
d_weight_ih = np.dot(d_hidden, batch_x) / batch_size + reg_lambda * self.weight_ih
d_bias_h = np.mean(d_hidden, axis=1, keepdims=True)
# 更新权重和偏置
self.weight_ih -= learning_rate * d_weight_ih
self.bias_h -= learning_rate * d_bias_h
self.weight_ho -= learning_rate * d_weight_ho
self.bias_o -= learning_rate * d_bias_o
def predict(self, x_test):
# 归一化测试数据
x_test_mean = np.mean(x_test, axis=0)
x_test_std = np.std(x_test, axis=0)
x_test_norm = (x_test - x_test_mean) / x_test_std
# 前向传播
hidden = self._sigmoid(np.dot(self.weight_ih, x_test_norm.T) + self.bias_h)
output = np.dot(self.weight_ho, hidden) + self.bias_o
# 反归一化输出
output_denorm = output.T * x_test_std[-1] + x_test_mean[-1]
return output_denorm
def _sigmoid(self, x):
return 1 / (1 + np.exp(-x))
def _sigmoid_derivative(self, x):
return x * (1 - x)
def save_weights(self, file_path):
# 将权重保存到文件
np.savez(file_path, weight_ih=self.weight_ih, bias_h=self.bias_h, weight_ho=self.weight_ho, bias_o=self.bias_o)
def load_weights(self, file_path):
# 从文件中加载权重
if osp.exists(file_path):
data = np.load(file_path)
self.weight_ih = data['weight_ih']
self.bias_h = data['bias_h']
self.weight_ho = data['weight_ho']
self.bias_o = data['bias_o']
def load_data(file_path):
# 从xlsx文件中加载数据
workbook = opx.load_workbook(file_path)
sheet = workbook.active
data = []
for row in sheet.iter_rows(min_row=2, values_only=True):
data.append(row)
data = np.array(data, dtype=np.float32)
x = data[:, :-1]
y = data[:, -1:]
return x, y
```
接下来,我们需要创建主函数模块,命名为`main.py`:
```python
import numpy as np
import matplotlib.pyplot as plt
from sklearn.metrics import r2_score, mean_absolute_error, mean_squared_error
from bp_network import BPNetwork, load_data
def main():
# 加载数据
x_train, y_train = load_data('data.xlsx')
x_test, y_test = x_train[-40:], y_train[-40:]
x_train, y_train = x_train[:-40], y_train[:-40]
# 创建BP网络
input_size = x_train.shape[1]
hidden_size = 8
output_size = 1
network = BPNetwork(input_size, hidden_size, output_size)
# 训练BP网络
learning_rate = 0.01
num_epochs = 1000
batch_size = 32
reg_lambda = 0.01
network.train(x_train, y_train, learning_rate, num_epochs, batch_size, reg_lambda)
# 保存BP网络权重
network.save_weights('weights.npz')
# 计算测试集的预测输出和真实输出
y_pred = network.predict(x_test)
y_true = y_test
# 计算R2值、MAE和MSE
r2 = r2_score(y_true, y_pred)
mae = mean_absolute_error(y_true, y_pred)
mse = mean_squared_error(y_true, y_pred)
print('R2: {:.4f}'.format(r2))
print('MAE: {:.4f}'.format(mae))
print('MSE: {:.4f}'.format(mse))
# 计算预测值和真实值之间的相对误差平均百分比
rel_err = np.abs((y_true - y_pred) / y_true).mean() * 100
print('Relative Error: {:.4f}%'.format(rel_err))
# 绘制测试集的各输入对应的实际输出和预测输出的拟合折线图
for i in range(x_test.shape[1]):
plt.figure()
plt.plot(x_test[:, i], y_true, label='True Value')
plt.plot(x_test[:, i], y_pred, label='Predicted Value')
plt.xlabel('Input {}'.format(i + 1))
plt.ylabel('Output')
plt.legend()
plt.show()
# 绘制R2图
plt.figure()
plt.scatter(y_true, y_pred)
plt.plot([y_true.min(), y_true.max()], [y_true.min(), y_true.max()], 'k--', lw=2)
plt.xlabel('True Value')
plt.ylabel('Predicted Value')
plt.title('R2: {:.4f}'.format(r2))
plt.show()
if __name__ == '__main__':
main()
```
上述代码中,我们首先从`data.xlsx`文件中加载数据,并将前3000行作为训练集,后40行作为测试集。然后,我们创建一个输入层大小为8、隐藏层大小为8、输出层大小为1的BP网络,并使用训练集对其进行训练。训练完成后,我们将BP网络的权重保存到`weights.npz`文件中。接着,我们使用测试集计算BP网络的预测输出和真实输出,并计算R2值、MAE和MSE。最后,我们绘制测试集的各输入对应的实际输出和预测输出的拟合折线图,以及R2图。
希望这个代码可以帮助到您!
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