How to copy anti diagonal elements to another matrix?

Hello, I need to copy both diagonals from one matrix to another. For example:

If (i==j or i==n+1-j) : MatA(i,j)=MatB(i,j);
else: MatA(i,j)=MatB(i,j)+1;

Thanks

[Stephen23]

Is the matrix always square?

[Ran Cohen]

Yes it is

Answer 1

[Stephen23]

Here is a simple solution using linear indexing. It assumes that both matrices are square and the same size.

>> A = randi(8,5)
A =
   8   3   3   5   6
   6   3   7   4   5
   4   7   5   4   2
   4   8   7   7   1
   6   6   6   3   1
>> N = numel(A);
>> R = size(A,1);
>> V = [1:R+1:N,R:R-1:N];
>> B = A+1;
>> B(V) = A(V)
B =
   8   4   4   6   6
   7   3   8   4   6
   5   8   5   5   3
   5   8   8   7   2
   6   7   7   4   1

Answer 2

[KSSV]

If A is your matrix. To get anti diagonal elements use:

diag(fliplr(A))

To get diagonal elements use:

diag(A)

[Ran Cohen]

And how do I copy the anti diagonal elements to a new matrix in the same places as the original one?

Answer 3

[Andrei Bobrov]

A = randi(127,7)
B = randi(127,7)

s = size(A);
lo = eye(s) + flip(eye(s),2) > 0;
B(lo) = A(lo);