更新 function.py

function.py

@@ -42,10 +42,15 @@ def classify(input_vector, dataSet, labels, k=2):
     - int: 预测的分类标签。
     """
     dataSet_size = dataSet.shape[0]
-    # 计算曼哈顿距离
+    # 计算马氏距离
+    cov_matrix = np.cov(dataSet.T)
+    inv_cov_matrix = np.linalg.inv(cov_matrix)
     diff_mat = np.tile(input_vector, (dataSet_size, 1)) - dataSet
-    abs_diff_mat = np.abs(diff_mat)
-    distances = abs_diff_mat.sum(axis=1)
+    distances = []
+    for i in range(dataSet_size):
+        distance = np.sqrt(np.dot(np.dot(diff_mat[i], inv_cov_matrix), diff_mat[i].T))
+        distances.append(distance)
+    distances = np.array(distances)
     # 对距离进行排序
     sorted_indices = distances.argsort()
     class_count = {}