这是一个计算器，可以帮助你进行数学计算，减少你的计算耗时，而且可以增加计算的准确率。-This is a calculator that can help you to make mathematical calculations to reduce your computing time-consuming, and can increase the calculation accuracy.

JAVA读取txt文档中的内容，据此计算四种搜索引擎返回文档的准确率-JAVA read the the txt document content, calculate the accuracy of the four search engines return documents

分词召回率和（R）和准确率（P）的统计，可以根据分词结果和标准结果计算出召回率和准确率值-Segmentation recall rate (R) and accuracy (P) statistics, can be calculated according to the results of the segmentation results and standard recall and accuracy values