更新 function.py

function.py

@@ -40,13 +40,23 @@ name = "陈垣豪"
 """
 
 def classify0(inX, dataSet,labels, k=3):
-    # 计算协方差矩阵并求其逆矩阵
-    cov_matrix = np.cov(dataSet,rowvar=False)
-    inv_cov_matrix = np.linalg.inv(cov_matrix)
+    # 归一化数据集
+    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
 
-    # 计算马氏距离
-    diff = dataSet - inX
-    distances = np.sum(diff @ inv_cov_matrix * diff, axis=1)
+    # 计算协方差矩阵并求其逆矩阵 (使用 SVD)
+    cov_matrix = np.cov(normalized_dataSet, rowvar=False)
+    U, S, VT = np.linalg.svd(cov_matrix)
+    inv_S = np.zeros_like(S)
+    nonzero_indices = S > 1e-10
+    inv_S[nonzero_indices] = 1 / S[nonzero_indices]
+    inv_cov_matrix = VT.T @ np.diag(inv_S) @ U.T
+
+    # 计算马氏距离的平方
+    diff = normalized_dataSet - normalized_inX
+    squared_distances = np.einsum('ij,jk->i', diff, inv_cov_matrix @ diff.T)
 
     # 获取距离最小的 k 个样本的索引
     sorted_indices = np.argsort(distances)[:k]