Find out the rows having same values in all columns of a matrix

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Hi,
I have a matrix with 4374 rows and 8 columns. I need to find the rows which have all the columns are of same values and it's repeated for 6 times.
As for example,
Let us consider a matrix, A= [ 0 0 0 0 1 0 0 ; 1 0 0 0 0 1 0; 1 0 0 0 0 1 0; 0 1 0 1 0 1 0; 1 0 0 0 0 1 0; 0 0 0 0 0 0 0; 1 0 0 0 0 1 0, 1 1 1 1 1 1 1; 1 0 0 0 0 1 0 , 0 0 1 1 0 1 0; 1 0 0 0 0 1 0; 0 0 0 0 1 0 0].
Here,0 0 0 0 1 0 0 is repeated twice and 1 0 0 0 0 1 0 is repeated for 6 times. Finally, I need to find and keep only those rows having repeated for 6 times (as like 1 0 0 0 0 1 0 in the given example) .
Can any please help me?

Accepted Answer

Stephen23
Stephen23 on 26 Nov 2018
Edited: Stephen23 on 26 Nov 2018
Something like this should get you started:
>> A = [0,0,0,0,1,0,0;1,0,0,0,0,1,0;1,0,0,0,0,1,0;0,1,0,1,0,1,0;1,0,0,0,0,1,0;0,0,0,0,0,0,0;1,0,0,0,0,1,0;1,1,1,1,1,1,1;1,0,0,0,0,1,0;0,0,1,1,0,1,0;1,0,0,0,0,1,0;0,0,0,0,1,0,0]
A =
0 0 0 0 1 0 0
1 0 0 0 0 1 0
1 0 0 0 0 1 0
0 1 0 1 0 1 0
1 0 0 0 0 1 0
0 0 0 0 0 0 0
1 0 0 0 0 1 0
1 1 1 1 1 1 1
1 0 0 0 0 1 0
0 0 1 1 0 1 0
1 0 0 0 0 1 0
0 0 0 0 1 0 0
>> [U,~,idx] = unique(A,'rows');
>> cnt = histc(idx,unique(idx)) % count how many times rows occur.
cnt =
1
2
1
1
6
1
>> out = U(cnt==6,:) % pick which the unique rows which occur >= 6 times.
out =
1 0 0 0 0 1 0
If you want to get those multiple row instances, then try this:
>> idr = ismember(idx,find(cnt==6));
>> A(idr,:)
ans =
1 0 0 0 0 1 0
1 0 0 0 0 1 0
1 0 0 0 0 1 0
1 0 0 0 0 1 0
1 0 0 0 0 1 0
1 0 0 0 0 1 0
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