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

7 views (last 30 days)
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

Accepted Answer

Jan
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.
  4 Comments
Sean de Wolski
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')

Sign in to comment.

More Answers (1)

Thorsten
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, :)

Categories

Find more on Matrices and Arrays in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by