How to use nested loop to produce the row and columns like that

Given a 2D array, called A, of size 5 x 5,

Sample Output: Given A = [2,4,8,7,3;2,2,3,4,3;5,5,4,2,7;8,2,7,3,9;1,2,3,4,5];

output:

2 4 8 7 3

2 2 3

5 5 7

8 2 7 3 9

1 2 3 4 5

% My code

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

rows = size(A,1) % the number of rows in A

columns = size(A,2) % the number of columns in A

B = [];

for row = 1:rows

for column = 1:columns

if (row == 2 || row == 3)

if (column == 3 || column == 4)

B = [B A(i)]

end

end

end

end

disp(B);

My code is wrong i thought

Answer 1

[Mathieu NOE]

hello

seems to me B is simply A but rows 2 and 3 for columns 3 and 4 are empty (filled with NaN)

code :

 A = [2,4,8,7,3;2,2,3,4,3;5,5,4,2,7;8,2,7,3,9;1,2,3,4,5];
 B = A;
 B(2:3,3:4) = NaN;

results :

A =

2 4 8 7 3

2 2 3 4 3

5 5 4 2 7

8 2 7 3 9

1 2 3 4 5

B =

2 4 8 7 3

2 2 NaN NaN 3

5 5 NaN NaN 7

8 2 7 3 9

1 2 3 4 5

[Shuoze Xu]

Yes. I know this method, but i want to do it by using nested loop.

[Mathieu NOE]

ok

A = [2,4,8,7,3;2,2,3,4,3;5,5,4,2,7;8,2,7,3,9;1,2,3,4,5];
 [m,n] = size(A);
 B = A;
 for ci = 1:m
     for cj = 1:n
         if (ci >= 2 && ci <= 3) && (cj >= 3 && cj <= 4) 
             B(ci,cj) = NaN;
         else
             B(ci,cj) = A(ci,cj);
         end
     end
 end

[Shuoze Xu]

Wow, it works.

Thank you so much

[Mathieu NOE]

My pleasure !

Answer 2

[Arif Hoq]

you did not clear your expection. you can try this

A = [2,4,8,7,3;2,2,3,4,3;5,5,4,2,7;8,2,7,3,9;1,2,3,4,5];
rows = size(A,1); % the number of rows in A
columns = size(A,2); % the number of columns in A
B = [];
for row = 1:rows
    for column = 1:columns
%         if row == 2 || row == 3 && column == 3 || column == 4
         if (row == 2 || row == 3)
            if (column == 3 || column == 4)
                B = [B A(row)]
            end
        end
    end
end

B = 2

B = 1×2

2 2

B = 1×3

2 2 5

B = 1×4

2 2 5 5

disp(B);

     2     2     5     5

[Shuoze Xu]

My expectation is to remove the elements in the third and fourth columns of the second row, and the third and fourth columns of the third row and print the array.

[Shuoze Xu]

using the nested loop