diff --git a/function.py b/function.py index d9b0ba1..fbd7ac4 100644 --- a/function.py +++ b/function.py @@ -29,19 +29,22 @@ name = "章程鸿" import numpy as np from sklearn.preprocessing import StandardScaler - def sigmoid(z): return 1.0 / (1 + np.exp(-z)) +def compute_gradient(X_batch, y_batch, weights): + z = np.dot(X_batch, weights) + h = sigmoid(z) + gradient = np.dot(X_batch.T, (h - y_batch)) / len(y_batch) + return gradient def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64): m, n = X.shape weights = np.random.randn(n) * 0.01 best_weights = weights.copy() best_accuracy = 0 - wait = 0 - for i in range(iterations): + for _ in range(iterations): indices = np.random.permutation(m) X_shuffled = X[indices] y_shuffled = y[indices] @@ -49,10 +52,7 @@ def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64): for j in range(0, m, batch_size): X_batch = X_shuffled[j:j + batch_size] y_batch = y_shuffled[j:j + batch_size] - z = np.dot(X_batch, weights) - h = sigmoid(z) - gradient = np.dot(X_batch.T, (h - y_batch)) / len(y_batch) - + gradient = compute_gradient(X_batch, y_batch, weights) weights -= learning_rate * gradient # 计算训练集准确率 @@ -60,21 +60,16 @@ def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64): if train_accuracy > best_accuracy: best_accuracy = train_accuracy best_weights = weights.copy() - wait = 0 - else: - wait += 1 return best_weights - def predict_logreg(X, weights): z = np.dot(X, weights) h = sigmoid(z) - return np.where(h > 0.5, 1, 0) + return np.where(h >= 0.5, 1, 0) def load_data(filepath): - data = [] - labels = [] + data, labels = [], [] with open(filepath, 'r') as f: for line in f: line = line.strip().split() @@ -85,17 +80,14 @@ def load_data(filepath): data = np.array(data) labels = np.array(labels) - target_variable = np.where((labels == 2) | (labels == 3), 0, labels) return data, target_variable - def accuracy(X, y, weights): predictions = predict_logreg(X, weights) return np.mean(predictions == y) - if __name__ == "__main__": X_train, y_train = load_data("./horse-colic.data") X_test, y_test = load_data("./horse-colic.test") @@ -109,3 +101,4 @@ if __name__ == "__main__": final_accuracy = accuracy(X_test, y_test, final_weights) print(f"最终测试集的准确率: {final_accuracy:.4f}") +