i've a matrix of 6x4 and i want to count the rows how many times it occur in a matrix

 let say the matrix is 

 A=[ 12 45 67 89
     34 56 78 65
     12 45 67 89
     53 55 21 90
     12 45 67 89
     53 55 21 90 ]

i want the output to be as:

     12 45 67 89 ----- 3  % because it occurs 3 times
     34 56 78 65 ------1
     53 55 21 90 ------2

plz help me

Answer 1

[Azzi Abdelmalek]

A=[ 12 45 67 89
   34 56 78 65
   12 45 67 89
   53 55 21 90
   12 45 67 89
   53 55 21 90 ]
[a,b,c]=unique(A,'rows','stable');
v=arrayfun(@(x) sum(c==x),1:size(a,1))';
out=[a v]

[Emma Cairns]

I have an instance where I need to do this twice with two separate matrices and I keep getting the same output for both using this code, is there any way I can make it work? Thanks!

[Jan]

@Emma: Yes, there is a way. Of course there is. If you post the relevant part of your code (preferably as a new question and not by high-jacking this thread), we can even suggest a solution.

Andrei's method is slightly faster and (c)leaner.

Answer 2

[Andrei Bobrov]

   A=[ 12 45 67 89
       34 56 78 65
       12 45 67 89
       53 55 21 90
       12 45 67 89
       53 55 21 90 ];

[a,c,c] = unique(A,'rows');
out = [a, histc(c,1:max(c))];