matlab读写文件总结，实现.txt,.dat等多种文件的读写操作，举例说明矩阵读写的要点-Matlab read and write files to summarize, to achieve a variety of file read and write in txt, dat, etc., illustrate the main points of the matrix to read and write

对txt格式的文件读取，并再次输出至txt中(read the file format.txt and then write to a file format txt)