generated from LufsX/Experiment-LogReg
This commit is contained in:
+45
-30
@@ -29,6 +29,51 @@ name = "章程鸿"
|
||||
import numpy as np
|
||||
from sklearn.preprocessing import MinMaxScaler
|
||||
from sklearn.model_selection import train_test_split
|
||||
|
||||
def sigmoid(z):
|
||||
return 1.0 / (1 + np.exp(-z))
|
||||
|
||||
def compute_gradient(X_batch, y_batch, weights, lambda_reg):
|
||||
z = np.dot(X_batch, weights)
|
||||
h = sigmoid(z)
|
||||
gradient = np.dot(X_batch.T, (h - y_batch)) / len(y_batch)
|
||||
gradient += (lambda_reg / len(y_batch)) * weights # L2正则化
|
||||
return gradient
|
||||
|
||||
def train_logreg(X, y, learning_rate=0.001, iterations=10000, batch_size=64, lambda_reg=0.1):
|
||||
m, n = X.shape
|
||||
weights = np.random.randn(n) * np.sqrt(2. / n) # He初始化
|
||||
best_weights = weights.copy()
|
||||
best_accuracy = 0
|
||||
|
||||
for _ in range(iterations):
|
||||
indices = np.random.permutation(m)
|
||||
X_shuffled = X[indices]
|
||||
y_shuffled = y[indices]
|
||||
|
||||
for j in range(0, m, batch_size):
|
||||
X_batch = X_shuffled[j:j + batch_size]
|
||||
y_batch = y_shuffled[j:j + batch_size]
|
||||
gradient = compute_gradient(X_batch, y_batch, weights, lambda_reg)
|
||||
weights -= learning_rate * gradient
|
||||
|
||||
# 计算训练集准确率
|
||||
train_accuracy = accuracy(X, y, weights)
|
||||
if train_accuracy > best_accuracy:
|
||||
best_accuracy = train_accuracy
|
||||
best_weights = weights.copy()
|
||||
|
||||
# 动态调整学习率
|
||||
if _ % 100 == 0 and train_accuracy > 0.95: # 达到高准确率时减小学习率
|
||||
learning_rate *= 0.9
|
||||
|
||||
return best_weights
|
||||
|
||||
def predict_logreg(X, weights):
|
||||
z = np.dot(X, weights)
|
||||
h = sigmoid(z)
|
||||
return np.where(h >= 0.5, 1, 0)
|
||||
|
||||
def load_data(filepath):
|
||||
data, labels = [], []
|
||||
with open(filepath, 'r') as f:
|
||||
@@ -58,36 +103,6 @@ def load_data(filepath):
|
||||
|
||||
return data, target_variable
|
||||
|
||||
def load_data(filepath):
|
||||
data, labels = [], []
|
||||
with open(filepath, 'r') as f:
|
||||
for line in f:
|
||||
line = line.strip().split()
|
||||
if len(line) >= 1 and line[-1].isdigit():
|
||||
line_data = [0 if x == '?' else float(x) for x in line[:-1]]
|
||||
data.append(line_data)
|
||||
labels.append(int(line[-1]))
|
||||
|
||||
data = np.array(data)
|
||||
labels = np.array(labels)
|
||||
|
||||
# 检查特征数量
|
||||
num_features = data.shape[1]
|
||||
print(f"特征数量: {num_features}")
|
||||
|
||||
# 特征选择:去掉特征3(索引2)和特征24~28(索引23~26),确保索引有效
|
||||
indices_to_delete = [2] # 特征3
|
||||
if num_features > 24: # 确保特征数量足够
|
||||
indices_to_delete += list(range(24, 27)) # 特征24到27(索引23到26)
|
||||
|
||||
# 删除特征
|
||||
data = np.delete(data, indices_to_delete, axis=1)
|
||||
|
||||
# 将标签二分类化,特征23(索引22)取值2和3合并为0,其余为1
|
||||
target_variable = np.where((labels == 2) | (labels == 3), 0, 1)
|
||||
|
||||
return data, target_variable
|
||||
|
||||
|
||||
|
||||
# 其余代码保持不变
|
||||
|
||||
Reference in New Issue
Block a user