此代码应用于将xml文件转换为mat文件。在图像的目标识别时我们需要获得一些图像的点坐标。但是通过label me。我们只能获得xml文件的形式，这样我们就需要将xml文件转换为mat文件。方便在matlab的语言环境中进行处理-This code is used in the xml file into mat file. When the target image recognition we need at some point in image coordinates. But by label me. We can only get in the form of xml files, so we need to convert the file to mat xml file. Facilitate processing matlab language environment