hr_type2.m

matlab写的数字信号处理源代码,里面包括最基本的fft计算

function [Hr,w,b,L] = Hr_Type2(h);
% Computes Amplitude response of Type-2 LP FIR filter
% ---------------------------------------------------
% [Hr,w,b,L] = Hr_Type2(h)
% Hr = Amplitude Response
%  w = frequencies between [0 pi] over which Hr is computed
%  b = Type-2 LP filter coefficients
%  L = Order of Hr
%  h = Type-2 LP impulse response
% 
 M = length(h);
 L = M/2;
 b = 2*[h(L:-1:1)];
 n = [1:1:L]; n = n-0.5;
 w = [0:1:500]'*pi/500;
Hr = cos(w*n)*b';