how can i save the even index to a matrix 2:5 using for loop

i print the even position in matrix z but the qausition is to save the output of the loop which is even index into a other matrix 2:5 using for loop . this is the code to produce an even endex

clear all

clc

z=randi([1 10],5,10)

for i=1:5

if(mod(i,2)==0)

for j=1:10

if(mod(j,2)==0)

fprintf('even index:%d\n',z(i,j))

end

end

end

end

Answer 1

[Sargondjani]

I think you want something like this:

(which you could speed up by pre-allocating MAT=NaN(2,5))

cnt_rows = 0;

cnt_cols = 0;

for i=1:5

if(mod(i,2)==0)

cnt_rows = cnt_rows+1;

for j=1:10

if(mod(j,2)==0)

cnt_cols = cnt_cols+1;

MAT(cnt_rows,cnt_cols) = z(i,j);

end

end

end

end

Answer 2

[Chris]

z=randi([1 10],5,10)

z = 5×10

10 3 6 8 4 7 10 6 2 7 8 9 7 1 1 3 2 3 4 1 6 9 3 6 8 8 2 5 2 3 7 10 9 10 8 6 2 6 7 1 6 6 8 4 6 4 2 4 10 10

newmatrix = [];
for i=1:5
  if(mod(i,2)==0)
      for j=1:10
         if(mod(j,2)==0)
%              fprintf('even index:%d\n',z(i,j))
             newmatrix(end+1) = z(i,j);
         end
      end
  end
end
newmatrix = reshape(newmatrix,5,2)'

newmatrix = 2×5

9 1 3 3 1 10 10 6 6 1

Alternatively, move down the columns in the inner loop. Then a 2x5 matrix would fill up naturally, retaining the orientation of the larger matrix.

z=randi([1 10],5,10)
newmatrix = zeros(2,5);
idx = 1;
for j=1:10
  if(mod(j,2)==0)
      for i=1:5
         if(mod(i,2)==0)
%              fprintf('even index:%d\n',z(i,j))
             newmatrix(idx) = z(i,j);
             idx = idx+1;
         end
      end
  end
end
newmatrix