The real-valued amplitude response

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.

Matlab header:

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]

Answer 1

[Matt J]

The examples in the documentation will be helpful

https://www.mathworks.com/help/matlab/ref/fft.html#buuutyt-7