说明：  该文档格式为pdf，里边详细介绍了对clplot实时曲线类的一些改进方法，增加打印预览，数据保存，文件打开，并且附有完整的程序代码，不失为一篇好文章
(The document format for the pdf, of the inside details of real-time curve clplot some type of improvement to increase the print preview, data, documents opened, and with the complete program code is, after all, a good article)