How can I use Kronecker delta for 3d matrix

I have a 10x10x10 = s(i,j,l) matrix. Lets say i,j,l rpresent the indices. How would I implement the Kronecker delta for the 3D case like the below 2D case? n=10

2D: delta(sij- s(pbc(i+1,n),j). The idea is if s_i = s_j then delta will give us 1 else 0.

How would I get like that in 3D?

[Torsten]

delta(sij- s(pbc(i+1,n),j)

Not clear what this expression (with unbalanced parenthesis) wants to tell us.

Answer 1

[Vinayak Choyyan]

Hi,

As per my understanding, you would like to create a 10x10x10 matrix with 0 in all locations except when indices i=j=k.

Please try the following code:

a=zeros(10,10,10);
for i = 1:10
    a(i,i,i)=1;
end

To know more about zeros function check out this link

Create array of all zeros - MATLAB zeros - MathWorks India

and to know more about for loop in MATLAB please check out this link

for loop to repeat specified number of times - MATLAB for - MathWorks India