code in signal processing

Hi people, I have a problem with a code.

A = [ 1 2 3 4]; % amplitude fr = [20 30 40 50]; % frequency

% Number of time samples, and number of samples per FFT Nt = 1024;

% Sampling freqency fs = 1000;

% Frequency spacing df = fs/Nt;

% Time t = [0:Nt-1]/fs;

I want to sum four signals as:

y = A*cos(2*pi*fr*t)

I want to use a FOR to do it, but the A and fr goes until 4 and the t goes until 1024.

I would like to do something

y = 1*cos(2*pi*20*t) + 2*cos(2*pi*30*t) + 3*cos(2*pi*40*t) + 4*cos(2*pi*50*t);

But I want to use a FOR.

How can I do it?

thanks

Answer 1

[Walter Roberson]

y = zeros(size(t));
for K = 1:length(A)
  y = y + A(K) * cos(2*pi*fr(K)*t);
end