Azzera filtri
Azzera filtri

Signals Question difference equation: Write a function y=diffeqn(a,x,yn1) which computes the output y[n] determined by the first-order system y[n]=ay[n-1]+x[n]

2 visualizzazioni (ultimi 30 giorni)
I need to Write a function y=diffeqn(a,x,yn1) which computes the output y[n] of the causal system determined by the first-order autoregression system y[n]=ay[n-1]+x[n] The input vector x, contains x[n] for 0 ≤ n ≤ N − 1 and yn1 supplies the value of y[-1]. The output vector y contains y[n] for 0 ≤ n ≤ N − 1.
Note that y[−1] is necessary for computing y[0], which is the first step of autoregression. Use a for loop in your M-file to compute
  5 Commenti
Rick Rosson
Rick Rosson il 11 Set 2014
I don't think you need a function within a function. Instead, you need a function that computes y as required and then a script that calls your function once or perhaps several times to test out your function.

Accedi per commentare.

Risposta accettata

Image Analyst
Image Analyst il 11 Set 2014
Hint, in test.m have both of these functions.
function test()
a = 10; % For example.
x = randi(9, 1, 7); % 1 by 7 array of integers
yn1 = 5; % For example.
yOut = diffeqn(a, x, yn1);
function [y, yn] =diffeqn(a,x,yn1)
for k = 1 : length(x)
y(k) = .....
end
% Not sure exactly what is meant by y[n], so return the full the y and y(n), i.e. the last element by itself.
yn = y(end);
Good luck.
  3 Commenti
Rick Rosson
Rick Rosson il 11 Set 2014
Modificato: Rick Rosson il 11 Set 2014
Since y(k) depends on y(k-1), the lower limit on the for loop should be 2 instead of 1. Otherwise, the code will trigger an error or you will need an if...else... block inside the loop (to handle the first element as a special case), which is not ideal.

Accedi per commentare.

Più risposte (1)

Rick Rosson
Rick Rosson il 11 Set 2014
Modificato: Rick Rosson il 11 Set 2014
Here's a start. Create a file called diffeqn.m and insert the following code:
function y = diffeqn(a,x,yn1)
% Number of rows:
N = size(x,1);
% Pre-allocate:
y = zeros(N,1);
y(1) = ...
for k = 2:N
...
...
...
end
end

Categorie

Scopri di più su Measurements and Feature Extraction in Help Center e File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by