Circular indexing of a 2D array

My Tp matrix is as follows,

1 2 3 7

Tp= 4 5 6 5

7 8 9 8

The code is,

for i=1:3
    for j=1:4
        if i==1 && j==1
            T(i,j)=Tp(i,j-1)
        end
        
        if i==2 && j==4
            T(i,j)=Tp(i,j+1)
        end
        
        
    end
end

I want the answer of the first IF condition to be T(i,j)=7, which is the element on the other side of the Tp matrix.

Second IF condition answer to be T(i,j)=4, which is the element on the other side of the Tp matrix.

How will I be able to do this?

Thanks in advance.

Answer 1

[Bjorn Gustavsson]

Something like this solves this problem:

for i=1:3
    for j=1:4
        if i==1 && j==1
            T(i,j)=Tp(i,1 + mod(4*123+j-2,4))
        end
        if i==2 && j==4
            T(i,j)=Tp(i,1 + mod(4*123+j+1,4))
        end
    end
end

You might have to fiddle around with mod/rem if you want to modify this to more general cases...

You could also have a look at the file exchange for something like circular indexing...

HTH

[Anuka Sooriyarachchi]

Thank you.