How to combination between this code A=zeros(8); for i=1:4 for j=1:8-(i+3) A(i,j)=1; end end A and this A=ones(4,8); for i=1:4 for j=1:8-(i) A(i,j)=0; end end A ?

How to combination between this code

A=zeros(8); 
for i=1:4 
    for j=1:8-(i+3) 
        A(i,j)=1; 
    end 
end 
A

and this

A=ones(4,8); 
for i=1:4 
    for j=1:8-(i) 
        A(i,j)=0; 
    end 
end 
A

after combination this result

       1     1     1     1     0     0     0     0
       1     1     1     0     0     0     0     0
       1     1     0     0     0     0     0     0
       1     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     1
       0     0     0     0     0     0     1     1
       0     0     0     0     0     1     1     1
       0     0     0     0     1     1     1     1

Answer 1

[Image Analyst]

Here's the easiest way to create A:

   A = [...
         1     1     1     1     0     0     0     0
         1     1     1     0     0     0     0     0
         1     1     0     0     0     0     0     0
         1     0     0     0     0     0     0     0
         0     0     0     0     0     0     0     1
         0     0     0     0     0     0     1     1
         0     0     0     0     0     1     1     1
         0     0     0     0     1     1     1     1];

I mean, why even use a loop at all? It's not needed.

Answer 2

[Star Strider]

If you want to do it in MATLAB code rather than manually, you only need one loop and the diag and fliplr functions:

A = zeros(8);
for k1 = 4:7
    A = A + diag(ones(1,8-k1),k1);
    A = A + diag(ones(1,8-k1),-k1);
end
A = fliplr(A)

produces:

A =

       1     1     1     1     0     0     0     0
       1     1     1     0     0     0     0     0
       1     1     0     0     0     0     0     0
       1     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     1
       0     0     0     0     0     0     1     1
       0     0     0     0     0     1     1     1
       0     0     0     0     1     1     1     1