Counting number of unique elements in a matrix

1 view (last 30 days)
I have a matrix, 2xT. It contains value PAIRS that are unique and some that are repeated.
I would like to order the matrix by the pairs that occur the most frequently.
myData = randi([0 20], [10000 2]); %make up some data
[C,ia,ic] = unique(myData,'rows');
such that %isequal(C(ic,:), myData) =1. Great.
I now try and work out the ordering
[nOccurances IX] = sort(histc(ic, 1:length(ic)), 'descend');
This gives nOccurances which looks sensible.
Now I try and output:
myDataSorted = myData(ic(IX),:);
The output value is just wrong.
Where have I gone wrong? Thank you!!
  2 Comments
Matlab2010
Matlab2010 on 10 Jan 2013
Edited: Matlab2010 on 10 Jan 2013
SOLVED:
myData = randi([0 20], [10000 2]); %make up some data
[C,ia,ic] = unique(myData,'rows');
[nOccurances IX] = sort(histc(ic, 1:length(ic)), 'descend');
idY = (nOccurances==0);
nOccurances(idY) = [];
IX(idY) = [];
myDataSorted = [nOccurances C(IX,:)];
Matt J
Matt J on 10 Jan 2013
Then you should either delete the question or submit then Accept your own solution as an Answer

Sign in to comment.

Answers (0)

Categories

Find more on Get Started with MATLAB in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!