做QT编程的都知道有个QWT第三方的开源绘图库，这里上传的内容是部分源码和注释，学的时候没找到这方面的资源,这里将注释的内容贡献出来。-QT programming do know that there is a third-party open-source graphics library QWT, upload content here is part of the source code and comments, to learn when not to find resources in this area, where the contents of the notes contributed.