Need help creating an array

I want to create the following array:

A = [-4 2 0 0 0; 2 -4 2 0 0; 0 2 -4 2 0; 0 0 2 -4 2; 0 0 0 2 -4];

' That's easy enough but I want to know if there is a way to make it neater, and also capable of being expanded to a higher number of rows.

So far I have tried: I = eye(5,5) .* -4

I = [-4 0 0 0 0; 0 -4 0 0 0; 0 0 -4 0 0; 0 0 0 -4 0; 0 0 0 0 -4];

Which is close, I guess. But need the two's in the columns aswell.

Thanks in advance

Answer 1

[Roger Stafford]

Do either of these two:

   n = 10; % <-- you choose n
   A = diag(-4*ones(n,1))+diag(2*ones(n-1,1),1)+diag(2*ones(n-1,1),-1);

or

   n = 10; % <-- you choose n
   t = [-4,2,zeros(1,n-2)];
   A = toeplitz(t,t);

Answer 2

[James Tursa]

And another way:

A = full(spdiags(repmat([2 -4 2],n,1),[-1 0 1],n,n));

And yet another way:

A = -4*eye(n);
A(2:n+1:end) = 2;
A(n+1:n+1:end) = 2;