choosing unique elements in the order that they appear in a column of a cell vector

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antonet on 30 Jan 2013
Dear all,
I have the following cell matrix
Out={
'MN' 'AER_KL1' 'Bdrerv_1'
'MN' 'AER_KL1' 'Bdrerv_1'
'MN' 'AER_KL1' 'Bdrerv_1'
'MN' 'AER_KL1' 'Bdrerv_1'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'eorftr>2'
'MN' 'AER_KL1' 'eorftr>2'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' '344 edd' }
I want to simplify this matrix so as to have the following specific structure
'MN' 'AER_KL1' 'Bdrerv_1'
'MN' 'AER_KL1' 'ksitre +2er'
'MN' 'AER_KL1' 'eorftr>2'
'MN' '100_pr' 'se 34'
'MN' '100_pr' 'fjgitow f12'
'MN' '100_pr' '344 edd' }
As you can see I want to select the unique elements from the last column in the order that appear in “out” and construct the above simplified matrix.
IS there any quick/efficient code for doing this?
The above matrix is an example
My original data set is of dimension 25000 by 4. So a general code for doing this is greatly appreciated

Jan on 30 Jan 2013
If you have a modern version of Matlab, the unique command can be controlled by teh 'first' flag to reply the first index.
Sean de Wolski on 30 Jan 2013
Well 'first' returns the first index, not necessarily 'stable' order; consider:
>> [uv,idx] = unique([3;2;3;1],'first')

Thorsten on 30 Jan 2013
Edited: Thorsten on 30 Jan 2013
You can to it "by feet"
unique_rows = 1;
for i = 2:size(Out, 1)
equals_row = 0;
for j = 1:numel(unique_rows)
equal_row = strcmp(Out{i, 3}, Out{unique_rows(j), 3});
if equal_row, break, end
end
if ~equal_row, unique_rows(end+1) = i, end
end
Out_simple = Out(unique_rows, :)

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