how to plot difference equation using matlab

how to plot difference equation using matlab ex:y[n]=x[n]+x[n-2]

Answer 1

[Muhammad Usman Saleem]

Please give some more explanations about equations?

Like how they look like?

What are their input parameters?

[rami saleh]

it was a Frequency response : h(w)=(e^-jw)*(2cos(w))=1+(e^-j2w) and I transform it with hand calculation to this difference equation and there are no other parameters in this question but also i found the Impulse response:h[n)=delta(n)+delta(n-2) if it helps

[Muhammad Usman Saleem]

see @walter answer

Answer 2

[Walter Roberson]

y = x(3:end) - x(1:end-2);