hr_type1.m

来自「很多matlab的源代码」· M 代码 · 共 16 行

function [Hr,w,a,L] = Hr_Type1(h)
% Computes Amplitude response Hr(w) of a Tyoe-1 Lp FIr filter
% -------------------------------------------------------------
% [Hr,w,a,L] = Hr_Type1(h)
% Hr = Amplitude Response
% w = 500 frequencies between [0 pi] over which Hr is computed
% a = Type-1 LP filter cofficients
% L = Order of Hr
% h = Type-1 LP filter impulse response
%
M = length(h);
L = (M-1)/2;
a = [h(L+1)  2*h(L:-1:1)];  %1x(L+1) row vector
n = [0:1:L];
w = [0:1:500]'*pi/500;
Hr = cos(w*n)*a';