From c44940de9dac12a9f08e34997bdcd7a50a761c10 Mon Sep 17 00:00:00 2001 From: wujunjie <297081150@qq.com> Date: Thu, 26 Sep 2024 11:01:36 +0800 Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0=20function.py?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- function.py | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/function.py b/function.py index 86aba4b..9c2a024 100644 --- a/function.py +++ b/function.py @@ -38,7 +38,7 @@ name = "吴俊煯" # 这里写自己的代码实现 -def classify0(inX, dataSet, labels,k=4): +def classify0(inX, dataSet, labels,k=3): """ KNN 分类算法。 @@ -50,27 +50,23 @@ def classify0(inX, dataSet, labels,k=4): Returns: - int: 预测的分类标签。 """ - if dataSet.shape[0] == 0: - raise ValueError("数据集为空") + # 特征缩放 + scaler = StandardScaler() + dataSet_scaled = scaler.fit_transform(dataSet) + inX_scaled = scaler.transform(inX.reshape(1, -1)) - # 确保 k 不大于数据集的大小 - k = min(k, dataSet.shape[0]) - - # 计算测试样本与每个训练样本之间的距离 - diffMat = np.tile(inX, (dataSet.shape[0], 1)) - dataSet + # KNN 分类 + dataSetSize = dataSet_scaled.shape[0] + diffMat = np.tile(inX_scaled, (dataSetSize, 1)) - dataSet_scaled sqDiffMat = diffMat ** 2 distances = np.sqrt(sqDiffMat.sum(axis=1)) - - # 对距离进行排序,并获取索引 sortedDistIndicies = distances.argsort() - # 选择距离最小的k个点 classCount = {} for i in range(k): voteIlabel = labels[sortedDistIndicies[i]] classCount[voteIlabel] = classCount.get(voteIlabel, 0) + 1 - # 多数投票 sortedClassCount = sorted(classCount.items(), key=lambda item: item[1], reverse=True) return sortedClassCount[0][0]