Compare matrix element without loops
4 views (last 30 days)
Show older comments
Hi,
Is there any way to get same result without using loops?
G = [5 8; 8 5; 3 9; 7 3; 1 4; 5 10; 6 7; 4 10; 4 7; 1 6];
n = 2;
nG = size(G,1);
for ii=1:nG
zz =1;
isDom = [];
for kk=1:n
for jj=1:nG
if ii ~= jj
isDom(zz) = G(ii,kk) < G(jj,kk);
zz = zz +1;
end
end
end
R(ii) = sum(isDom==1);
end
0 Comments
Accepted Answer
dpb
on 4 May 2019
Edited: dpb
on 4 May 2019
Not w/o zero loops, think not, but can reduce to one...
idx=1:nG; % working index array for element logical lookup/exclusion
R=zeros(nG,1); % preallocate
for i=1:nG
isDom=(G(i,:)-G(idx~=i,:));
R(i)=sum(isDom(:)<0);
end
You can eliminate the intermediate isDom temporary if desired..."exercise for the student" :)
2 Comments
dpb
on 4 May 2019
You can also, of course, remove the explicit loop via arrayfun, but the loop is still there and resulting code is somewhat obfuscated and may well be slower, besides...
More Answers (0)
See Also
Categories
Find more on Matrix Indexing in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!