Sort columns by maximum value?
4 views (last 30 days)
Show older comments
Having trouble with this one, how do I sort columns by the maximum value contained within them (must be a single line command)?
For example I have the following matrix:
5 -2 3
-10 6 2
0 0 1
The correct output should be:
3 5 -2
2 -10 6
1 0 0
I have narrowed it down to involving the max(x) command which returns the list of maximal values for each column as such:
5 6 3
But how can I then number these values in ascending order without first sorting them? e.g:
2 3 1
If I could do that then it would be simple to reorder from there. Again this problem seems easy using temporary variables but I have to do it as a single line. Any help appreciated.
0 Comments
Answers (4)
Azzi Abdelmalek
on 18 Dec 2013
Edited: Azzi Abdelmalek
on 18 Dec 2013
We can make it simple
y=x(:,sortrows([max(x);1:size(x,2)]',1)*[0;1])
Sean de Wolski
on 17 Dec 2013
Edited: Sean de Wolski
on 17 Dec 2013
x = [5 -2 3
-10 6 2
0 0 1]
[~,idx] = sort(max(x));
y = x(:,idx)
1 Comment
Sean de Wolski
on 17 Dec 2013
Edited: Sean de Wolski
on 17 Dec 2013
Personally, I would never recommend doing this operation in a single line because it will just obfuscate it. If you really need to, there's probably a way using arrayfun but it'll look hideous and be unreadable.
Or you could just stack them together :)
[~,idx] = sort(max(x));y = x(:,idx)
Azzi Abdelmalek
on 17 Dec 2013
x=[5 -2 3
-10 6 2
0 0 1];
y=x(:,setdiff(accumarray(max(x)',(1:size(x,2))'),0,'stable'))
1 Comment
Andrei Bobrov
on 18 Dec 2013
y=x(:,nonzeros(accumarray(max(x)',(1:size(x,2))')));
Andrei Bobrov
on 18 Dec 2013
with subsref
y = x(:,subsref(sortrows([max(x)',(1:size(x,2))'],1),struct('type','()','subs',{{':',2}})))
0 Comments
See Also
Categories
Find more on Shifting and Sorting Matrices 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!