优化的互信息特征选择方法

在文本分类中，互信息是一种被广泛应用的特征选择方法，但是该方法仅考虑了特征的文档频而没有考虑特征的词频，导致它经常倾向于选择出现频率较低的特征。为此，提出了一个新的文档频并把它引入到互信息方法中，从而获得了一种优化的互信息方法。该优化的互信息方法不但考虑了特征的文档频而且还考虑了特征出现的词频。实验结果表明该优化的互信息方法性能良好。

Optimized mutual information feature selection method

Mutual Information（MI） is a feature selection method that is used widely in text categorization,but this method only takes into account document frequency of selected features and ignores word frequency of selected features.For this reason,MI is inclined to select lower-frequency features.In this case,a new document frequency is presented and introduced into MI, so that an optimized MI method is proposed.The optimized MI not only pays attention to document frequency of selected features but also attaches importance to word frequency of selected features.The experimental results show that the optimized MI is promising.