说明：  此程序是用C语言编写的FIR数字滤波器，程序分块相当完整清晰：打开文件，读取数据文件，运算滤波，结果写入文件，关闭文件。已经通过验证
(This program is written in C language FIR digital filters, the program block quite a complete and clear: open the file, read data files, computing filtering, the results of written document, close the file. Has passed validation)