贝叶斯并行分类分析
1 贝叶斯训练器
所在包：Package org.apache.mahout.classifier.bayes实现机制The implementation is divided up into three parts:
The Trainer -- responsible for doing the counting of the words and the labels
The Model -- responsible for holding the training data in a useful way
The Classifier -- responsible for using the trainers output to determine the category of previously unseen documents
The trainer is manifested in several classes:
BayesDriver
创建Hadoop贝叶斯作业，输出模型，这个类封装了4个map/reduce类。
common.BayesFeatureDriver
common.BayesTfIdfDriver
common.BayesWeightSummerDriver
BayesThetaNormalizerDriver
训练器的输入是KeyValueTextInputFormat格式，第一个字符时类标签，剩余的是特征（单词），如下面的格式：
hockey puck stick goalie forward defenseman referee ice checking slapshot helmet football field football pigskin referee helmet turf tackle hockey 和football 是类标签，剩下的是特征。