更新 function.py
Gitea Actions Challenge Test / Challenge-Actions (push) Successful in 10s

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2024-10-17 16:16:42 +08:00
parent cb8607b935
commit 0d1754a486
+14 -22
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@@ -39,38 +39,30 @@ name = "陈垣豪"
- int: 预测的分类标签。 - int: 预测的分类标签。
""" """
def classify0(inX, dataSet, labels, k=3): def classify0(inX, 数据集, 标签, k=3):
# Normalize the dataset
dataSet_mean = np.mean(dataSet, axis=0)
dataSet_std = np.std(dataSet, axis=0)
normalized_dataSet = (dataSet - dataSet_mean) / dataSet_std
normalized_inX = (inX - dataSet_mean) / dataSet_std
# 计算协方差矩阵并求其逆矩阵 # 计算协方差矩阵并求其逆矩阵
cov_matrix = np.cov(normalized_dataSet, rowvar=False) cov_matrix = np.cov(数据集,rowvar=False)
inv_cov_matrix = np.linalg.inv(cov_matrix) inv_cov_matrix = np.linalg.inv(cov_matrix)
# 计算马氏距离 # 计算马氏距离
diff = normalized_dataSet - normalized_inX diff = dataSet - inX
distances = np.einsum('ij,jk->i', diff, inv_cov_matrix @ diff.T) # 使用 einsum 简化计算 distances = np.sum(diff @ inv_cov_matrix * diff, axis=1)
# 获取距离最小的 k 个样本的索引 # 获取距离最小的 k 个样本的索引
sorted_indices = np.argsort(distances)[:k] sorted_indices = np.argsort(distances)[:k]
# 获取 k 个最近邻的标签 # 获取 k 个最近邻的标签
nearest_labels = [labels[i] for i in sorted_indices] nearest_labels = [labels[i] for i in sorted_indices]
# 统计 k 个最近邻中每个类别的出现次数 # 统计 k 个最近邻中每个类别的出现次数
label_count = {} label_count = {}
weights = 1 / (distances[sorted_indices] + 1e-10) # Avoid division by zero for label in nearest_labels:
for i, label in enumerate(nearest_labels):
if label in label_count: if label in label_count:
label_count[label] += weights[i] label_count[label] += 1
else: else:
label_count[label] = weights[i] label_count[label] = 1
# 找到出现次数最多的标签 # 找到出现次数最多的标签
predicted_label = max(label_count, key=label_count.get) predicted_label = max(label_count, key=label_count.get)
return predicted_label return predicted_label提高准确率