Seeking help creating a double matrix of ones and minus ones

Hello,

I'm relatively new to matlab and I'm trying to create a matrix like the example below. But I can't seem to get the code correct. I've tried the following code neither of which are correct. Would somebody be able to help me out?

Much appreciated

N=5;
ot = ones(N,1);
A = spdiags([-ot -ot],[0 N],N,N*2);

and

A = sparse(tril(ones(N)));

1    -1
11   -1-1
111  -1-1-1
1111 -1-1-1-1
11111-1-1-1-1-1

Answer 1

[Iain]

 startpoint = eye(desired_size);
 positives = cumsum(startpoint)
 whole_thing = [positives -positives]