MATLAB: Delete rows with same elements

deletesame

a=[2 3 2;3 3 3;4 4 4;2 5 4; 3 5 5; 4 4 4; 7 3 4]
how do I delete only those rows where elemets repeat for entire row length. In this example matrix, the three rows with all 3s and all 4s where this happens.

Best Answer

Try this: 
a=[2 3 2;3 3 3;4 4 4;2 5 4; 3 5 5; 4 4 4; 7 3 4];
a_new = a(all(diff(a,[],2) ~= 0, 2),:)
If all the columns in a particular row are the same, the vector returned by the diff function will all be uniformly 0. The all function across rows (dimension = 2) detects that, and deletes those rows. 
a =
     2     3     2
     3     3     3
     4     4     4
     2     5     4
     3     5     5
     4     4     4
     7     3     4
a_new =
     2     3     2
     2     5     4
     7     3     4
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