diff --git a/function.py b/function.py index 420ecfb..932af46 100644 --- a/function.py +++ b/function.py @@ -25,8 +25,8 @@ import numpy as np """ 请在这里填写学号和姓名,不填写即成绩无效。 """ -id = "202210423xxx" -name = "test_name" +id = "202210423230" +name = "尹家立" """ @@ -53,6 +53,30 @@ def classify0(inX, dataSet, labels, k=0): Returns: - int: 预测的分类标签。 """ + # Step 1: 计算协方差矩阵的逆矩阵 + covMat = np.cov(dataSet, rowvar=False) # 计算协方差矩阵 + invCovMat = np.linalg.inv(covMat) # 计算协方差矩阵的逆 + + # Step 2: 计算马氏距离 + diffMat = dataSet - inX # 计算差值矩阵 + left = np.dot(diffMat, invCovMat) # 左乘协方差矩阵的逆 + mahalanobisDist = np.sqrt(np.sum(left * diffMat, axis=1)) # 计算马氏距离 + + # Step 3: 按距离排序,得到索引 + sortedDistIndices = mahalanobisDist.argsort() + + # Step 4: 选择距离最近的 k 个点的标签,并采用权重投票 + classCount = {} + for i in range(k): + voteLabel = labels[sortedDistIndices[i]] + distance = mahalanobisDist[sortedDistIndices[i]] + weight = 1 / (distance + 1e-5) # 距离越小权重越大,防止除零 + + classCount[voteLabel] = classCount.get(voteLabel, 0) + weight + + # Step 5: 按照加权后的类别得票数排序并返回得票最多的类别 + sortedClassCount = sorted(classCount.items(), key=lambda item: item[1], reverse=True) + return sortedClassCount[0][0] def load_data(file_path):