更新 function.py

function.py

@@ -1,106 +1,51 @@
-import os
-import csv
 import numpy as np
-import torch
-import torch.nn as nn
-import torch.optim as optim
-from sklearn.model_selection import train_test_split
-from sklearn.metrics import classification_report, confusion_matrix, accuracy_score, roc_auc_score
-from sklearn.preprocessing import StandardScaler
-from imblearn.over_sampling import SMOTE
 
-# 姓名和学号
- id = 202210423118 
- name = 刘国庆
+def load_data(filepath):
+    for delimiter in [',', ' ', '\t']:
+        try:
+            data = np.genfromtxt(filepath, delimiter=delimiter, missing_values='?', filling_values=np.nan)
+            if data.ndim < 2 or data.shape[1] < 2:
+                continue
+            data = data[~np.isnan(data).any(axis=1)]
+            if data.size == 0:
+                print(f"Error: No valid data after removing NaN rows in file '{filepath}'.")
+                return None, None
+            X = data[:, :-1]
+            y = data[:, -1]
+            if X.shape[0] != y.shape[0]:
+                print(f"Error: Feature and label count mismatch in file '{filepath}'")
+                return None, None
+            print(f"Loaded data from '{filepath}': {X.shape[0]} samples, {X.shape[1]} features.")
+            return X, y
+        except Exception as e:
+            print(f"Error loading data with delimiter '{delimiter}': {e}")
+    print(f"Error: File '{filepath}' may be empty or improperly formatted.")
+    return None, None
 
-# 读取 CSV 数据的函数
-def load_data(file_path):
-    if not os.path.exists(file_path):
-        raise FileNotFoundError(f"文件未找到: {file_path}")
-    
-    features = []
-    labels = []
-    with open(file_path, 'r') as csvfile:
-        reader = csv.reader(csvfile)
-        next(reader)  # 跳过标题行
-        for row in reader:
-            features.append([float(x) for x in row[:-1]])  # 假设最后一列为标签
-            labels.append(int(row[-1]))
-    return np.array(features), np.array(labels)
+def sigmoid(z):
+    return 1 / (1 + np.exp(-z))
 
-# 评估模型的函数
-def evaluate_model(y_true, y_pred, y_prob=None):
-    print("Confusion Matrix:")
-    print(confusion_matrix(y_true, y_pred))
-    print("\nClassification Report:")
-    print(classification_report(y_true, y_pred))
-    print(f"Accuracy: {accuracy_score(y_true, y_pred):.4f}")
-    
-    if y_prob is not None:
-        auc = roc_auc_score(y_true, y_prob)
-        print(f"AUC Score: {auc:.4f}")
+def train_logreg(X, y, learning_rate=0.01, epochs=1000):
+    X = np.c_[np.ones(X.shape[0]), X]
+    weights = np.zeros(X.shape[1])
+    for epoch in range(epochs):
+        z = np.dot(X, weights)
+        predictions = sigmoid(z)
+        gradient = np.dot(X.T, (predictions - y)) / y.size
+        weights -= learning_rate * gradient
+    return weights
 
-# 定义模型类
-class LogisticRegressionModel(nn.Module):
-    def __init__(self, input_size):
-        super(LogisticRegressionModel, self).__init__()
-        self.fc = nn.Linear(input_size, 1)
-        
-    def forward(self, x):
-        return torch.sigmoid(self.fc(x))
+def predict_logreg(X, weights):
+    X = np.c_[np.ones(X.shape[0]), X]
+    probabilities = sigmoid(np.dot(X, weights))
+    return (probabilities >= 0.5).astype(int)
 
-# 主函数
-def main():
-    # 加载数据
-    file_path = 'data.csv'  # 修改为你的 CSV 文件路径
-    X, y = load_data(file_path)
-
-    # 拆分数据集
-    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
-
-    # 处理不平衡数据
-    smote = SMOTE(random_state=42)
-    X_train_res, y_train_res = smote.fit_resample(X_train, y_train)
-
-    # 标准化数据
-    scaler = StandardScaler()
-    X_train_res = scaler.fit_transform(X_train_res)
-    X_test = scaler.transform(X_test)
-
-    # 转换为 PyTorch 张量
-    X_train_res = torch.tensor(X_train_res, dtype=torch.float32)
-    y_train_res = torch.tensor(y_train_res, dtype=torch.float32).view(-1, 1)
-    X_test = torch.tensor(X_test, dtype=torch.float32)
-    y_test = torch.tensor(y_test, dtype=torch.float32).view(-1, 1)
-
-    # 创建模型
-    model = LogisticRegressionModel(input_size=X_train_res.shape[1])
-
-    # 定义损失函数和优化器
-    criterion = nn.BCELoss()
-    optimizer = optim.Adam(model.parameters(), lr=0.001)
-
-    # 训练模型
-    model.train()
-    for epoch in range(100):
-        optimizer.zero_grad()  # 清空梯度
-        outputs = model(X_train_res)  # 前向传播
-        loss = criterion(outputs, y_train_res)  # 计算损失
-        loss.backward()  # 反向传播
-        optimizer.step()  # 更新权重
-        
-        if (epoch + 1) % 10 == 0:
-            print(f'Epoch [{epoch + 1}/100], Loss: {loss.item():.4f}')
-
-    # 评估模型
-    model.eval()
-    with torch.no_grad():
-        y_pred_prob = model(X_test).numpy().flatten()  # 获取预测概率
-        y_pred = (y_pred_prob > 0.5).astype(int)
-
-    # 评估模型
-    evaluate_model(y_test.numpy(), y_pred, y_pred_prob)
-
-if __name__ == "__main__":
-    main()
+# Load data and train model
+data_file_path = 'path_to_your_data/horse-colic.data'  # Update with your actual path
+X, y = load_data(data_file_path)
+if X is not None and y is not None:
+    weights = train_logreg(X, y)
+    predictions = predict_logreg(X, weights)
+    print("Weights:", weights)
+    print("Predictions:", predictions)