find common elements of the same row

hello, I need to find rows that have the same number in the same row eg (1 1).

• s1 0 0 0 1 0 0 1
• s2 1 0 0 0 0 1 0

How do I do that. I have an array of (40x1000) and I need to do that for every 2 columns and store the data in a separate file.

Thank you in advance

Answer 1

[Shameer Parmar]

You can do this..

let us consider, you have following input matrix..

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

A =

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

% as you want to check same numbers in rows, so you need to check it row wise as follows..

 count = 1;
 for i = 1:size(A,1)
     if length(A(i,:)) ~= length(unique(A(i,:)))
        rowIndex(count) = i;
        count = count + 1 ;
     end
 end

Output will be the new array, which will give you the row numbers (indices), which is having the same numbers in it..

Output:

 rowIndex =

     2     5

Answer 2

[KSSV]

doc unique.... by the way s1 0 0 0 1 0 0 1 have common [1 0]

Answer 3

[Shameer Parmar]

This is another Answer from my side..

If you have array of 40x1000, and all row and column contains 0's and 1's..

and you want to check if any row contains more than one 1's irrespective of 0's...then you can do this..

 count = 1;
 for i = 1:size(A,1)
     if sum(A(i,:)) >= 2
        rowIndex(count) = i;
        count = count + 1 ;
     end
 end