junk, index and unique on a matrix (how to keep matrix format)

Question

Using this method on a 8x8 matrix:

>> [junk,index] = unique(data,\'first\');        %# Capture the index, ignore junk
>> data(sort(index))                


        

Answer 1

If you want unique rows, while keeping original order, try this:

[M,ind] = unique(data, 'rows', 'first');
[~,ind] = sort(ind);
M = M(ind,:);

Example:

>> data = randi(2,[8 3]);
data =
     1     2     1
     1     2     1
     1     1     2
     2     2     2
     1     1     1
     2     2     2
     2     2     2
     2     1     1
>> M
M =
     1     2     1
     1     1     2
     2     2     2
     1     1     1
     2     1     1