hr_type2.m

很多matlab的源代码

function [Hr,w,b,L] = Hr_Type2(h)
% Computes Amplitude response  of a Tyoe-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 cofficients
% L = Order of Hr
% h = Type-2 LP filter 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';