有人能解释一下数据挖掘中分类和聚类的区别吗?

如果可以,请给出两者的例子以理解主旨。


当前回答

我认为分类是将数据集中的记录分类为预定义的类,甚至是在运行中定义类。我认为这是任何有价值的数据挖掘的先决条件,我喜欢把它看作无监督学习,即在挖掘数据和分类作为一个很好的起点时,一个人不知道他/她在寻找什么

另一端的聚类属于监督学习,即一个人知道要寻找什么参数,它们之间的相关性以及关键水平。我认为这需要对统计学和数学有所了解

其他回答

摘自《驯象人在行动》一书,我认为它很好地解释了两者的区别:

分类算法与聚类算法(如k-means算法)相关,但仍有很大不同。 分类算法是监督学习的一种形式,与无监督学习相反,无监督学习发生在聚类算法中。 监督学习算法是一种给出包含目标变量期望值的例子。无监督算法不会得到想要的答案,而是必须自己找到一些合理的答案。

如果你试图将大量的文件归档到你的书架上(根据日期或文件的其他规格),你是在分类。

如果要从这组工作表创建集群,则意味着工作表之间有一些类似的东西。

分类和聚类之间的主要区别是: 分类是借助类标签对数据进行分类的过程。另一方面,聚类类似于分类,但没有预定义的类标签。 分类与监督学习相适应。与此相反,聚类也被称为无监督学习。 分类方法提供训练样本,聚类方法不提供训练数据。

希望这对你有所帮助!

首先,像这里的许多回答一样:分类是有监督的学习,聚类是无监督的。这意味着:

Classification needs labeled data so the classifiers can be trained on this data, and after that start classifying new unseen data based on what he knows. Unsupervised learning like clustering does not uses labeled data, and what it actually does is to discover intrinsic structures in the data like groups. Another difference between both techniques (related to the previous one), is the fact that classification is a form of discrete regression problem where the output is a categorical dependent variable. Whereas clustering's output yields a set of subsets called groups. The way to evaluate these two models is also different for the same reason: in classification you often have to check for the precision and recall, things like overfitting and underfitting, etc. Those things will tell you how good is the model. But in clustering you usually need the vision of and expert to interpret what you find, because you don't know what type of structure you have (type of group or cluster). That's why clustering belongs to exploratory data analysis. Finally, i would say that applications are the main difference between both. Classification as the word says, is used to discriminate instances that belong to a class or another, for example a man or a woman, a cat or a dog, etc. Clustering is often used in the diagnosis of medical illness, discovery of patterns, etc.

通常,在分类中,您有一组预定义的类,并希望知道新对象属于哪个类。

聚类尝试将一组对象分组,并发现对象之间是否存在某种关系。

在机器学习的背景下,分类是监督学习,聚类是无监督学习。

也可以看看维基百科上的分类和聚类。