document about the digital signal processing,detailedly introduce how to design the filters including the FIR and IIR filters

包含书籍《数字信号处理-理论 算法与实现》胡广书及书籍随书光盘，其中包含约40个信号处理的子程序，概括了书中所涉及到的绝大部分算法。程序分别由FORTRAN语言和C语言编写。-Contains books, " Digital Signal Processing- Theory and Implementation of Algorithm" Guang-Shu Hu and books with book, which contains about 40 signal pro