Extract the first negative value in a matrix column
9 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
I have a 501x100000 Matrix, containing positive and some negative values. The values were calculated using random numbers. I need the value, not the index of the first negative entry in each column. If there is no negative value in the column it should be displayed by a 0.
simplified example:
A = [ 1, 2, 5, 6; -1, 4, 8,-4; -2, 3, 9, 1; -2,-1, 3,-1 ]
The answer I need (for that example) is:
-1,-1,0,-4
Thanks in advance for any help...
0 Kommentare
Akzeptierte Antwort
Azzi Abdelmalek
am 29 Mai 2013
Bearbeitet: Azzi Abdelmalek
am 29 Mai 2013
Edit
out=arrayfun(@(x) min([ 0 A(find(A(:,x)<0,1),x)]),1:size(A,2))
2 Kommentare
Weitere Antworten (2)
Iain
am 29 Mai 2013
for i = 1:cols
Answer = A(find(A(:,i)<0,1),i);
if isempty(Answer)
Out(i) = 0;
else
Out(i) = Answer;
end
end
0 Kommentare
Andrei Bobrov
am 29 Mai 2013
t = A < 0;
[~,jj] = find(t);
out = accumarray(jj,A(t),[],@(x)x(1))';
0 Kommentare
Siehe auch
Kategorien
Mehr zu Creating and Concatenating Matrices finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!