Filling the matrix entries

I have a matrix to deal with.

A=[1 2 3 4 5 6 7;4 6 7 4 5 8 7; 6 7 8 9 3 5 6];
for i=1:3
    A(i,i)=0;
end

In the above simple code I could change A(i,i) by 0. Now I want to start from the last entry(A(3,7)) and change to 0 in the similar way. In simple way A(3,7), A(2,6,) and A(1,5) should be changed by zero. I need it in the loop I started.

Answer 1

[Image Analyst]

Perhaps this:

A=[1 2 3 4 5 6 7;4 6 7 4 5 8 7; 6 7 8 9 3 5 6]

A = 3×7

1 2 3 4 5 6 7 4 6 7 4 5 8 7 6 7 8 9 3 5 6

for k = 1 : 3
    A(k, k+4)=0;
end
A % Display result

A = 3×7

1 2 3 4 0 6 7 4 6 7 4 5 0 7 6 7 8 9 3 5 0