hi here. I need your help to write my problem into matrix form. I don't real know how to do it really. could some one help me please? this is the equation to transform:

z*M i,j = M i+1,j + M i-1,j + M i,j+1 + M i,j-1 + A*(delta i,j )*M i,j

i and j are indexes of the eigenfunctions M

with Z and A = const