Where amplitude response A(w) is continuous and real-valued.
How i can write a Matlab function that uses the FFT to compute A(w) from the impulse
response h(n) at the frequency points.
function [A,w] = firamp(h,type,L)
% Amplitude response of a linear-phase FIR filter
% A : amplitude response at the frequencies w
w : [0:L-1]*(2*pi/L);
h : impulse response
type = [1,2,3,4]