extract data from matrix and store into a new matirx

 I want to extract data of row 6 and the last row from the test matrix. Here is my code:

test=[1 2;13 12; 3 0; 4 0; 5 3; 30 10; 2 10; 30 1;10 4; 50 9; 60 7]
      data=zeros(2,2);
      for j=1:2
          for i=1:6
         i=1+5;
              data(i,j)=test(i,j)
          end
      end
      data

the correct answer should be

data=[30 10 ; 60 7]

however, it comes up with something wrong.

Answer 1

[Star Strider]

You do not need the loop.

This works:

data = test([6 end],:);

data =
    30    10
    60     7

[kingsley]

Because my actual data is a 145 by 2 matrix matrix.And I want extract those data from row 6 and row6+5 and row row6+5+5.....till the last row of the matrix. In that case, how should I change my code? Or what approach will be better?

[Star Strider]

Try this:

actual_matrix = randi(9, 145, 2);
data = actual_matrix([6:5:end end], :);

The colon-indexing ends on row 141. If you want the last row as well, the ‘data’ assignment here will work.

If you only want rows 6 through 141 in steps of 5, the assignment becomes simply:

data = actual_matrix(6:5, :);

[kingsley]

thank you so much ! it works

[Star Strider]

As always, my pleasure!