Sorting elements of a matrix ignoring NaN
4 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Stephen
il 21 Mar 2016
Modificato: Azzi Abdelmalek
il 21 Mar 2016
Dear All,
I have the following 4x4 matrix have containing numbers and NaN:
have = [5 NaN 4 9;
4 0 NaN 9;
-6 NaN 2 3;
1 7 NaN -3]
I would like to assign a rank (ascending/descending) to the elements of each colum of the matrix have. In the sorting procedure, the NaNs should be ignored and elements with the same value (column 4) should have the same (tied) rank.That is, I would like to obtain the following matrices:
want_ascend = [4 NaN 2 3;
3 1 NaN 3;
1 NaN 1 2;
2 2 NaN 1]
want_descend = [1 NaN 1 1;
2 2 NaN 1;
4 NaN 2 2;
3 1 NaN 3]
My attempt involving the sort function does not successfully ignore the NaN (which are ranked too).
[~,attempt]=sort(have,1,'descend')
attempt =
1 1 2 1
2 3 4 2
4 4 1 3
3 2 3 4
Any help would be highly appreciated. Thanks!
0 Commenti
Risposta accettata
Azzi Abdelmalek
il 21 Mar 2016
Modificato: Azzi Abdelmalek
il 21 Mar 2016
have = [5 NaN 4 9;
4 0 NaN 9;
-6 NaN 2 3;
1 7 NaN -3]
idx=isnan(have)
[n,m]=size(have)
[have_ascend,have_descend]=deal(zeros(n,m))
for k=1:m
v=have(:,k)
[~,~,kk]=unique(v)
have_ascend(:,k)=kk;
end
have_ascend(idx)=nan
You can get have_descend from have_ascend
have_descend=bsxfun(@minus,max(have_ascend)+1,have_ascend)
0 Commenti
Più risposte (0)
Vedere anche
Categorie
Scopri di più su Shifting and Sorting Matrices in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!