Info
Cette question est clôturée. Rouvrir pour modifier ou répondre.
Advice on a few bottlenecks in my code
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
According to the profiler, I have four lines of code taking up 99% of my CPU time.
if(statment)
pCond = (bold_Phi(k,2) <= data(thisIdx : idx, 7));
else
pCond = (data(thisIdx : idx, 7) <= bold_Phi(k,2));
end
IDY = find( (data(thisIdx : idx, 1) == -1) & (pCond) & (data(thisIdx : idx, 11) == bold_Phi(k,p + 10)) );
IDZ = find( (dV(thisIdx : idx, :) <= -bold_Phi(k,3)) & (pCond) & (sCond) );
where bold_Phi and data are 2D matrices and dV is a vector.
I dont think the time penalty is coming from the indexing as the following statement is very quick
~isnan(data(thisIdx : idx, 3));
anything obvious I have missed that will help me speed up these few statements?
thank you
4 commentaires
Réponses (2)
Kye Taylor
le 21 Fév 2013
If you don't need the actual indices, you can omit the find command to save time. In particular, notice that the following code blocks are equivalent but the first does not use find:
data = rand(1000,1);
isBig = data>0.5;
bigData = data(isBig);
and
data = rand(1000,1);
isBigIdx = find(data>0.5);
bigData2 = data(isBigIdx);
1 commentaire
Mark Whirdy
le 22 Fév 2013
Modifié(e) : Mark Whirdy
le 22 Fév 2013
(Almost-) Never use the find() function!
I'd need to see the contents of the variables, but at first glance you can maybe just remove it altogether with same functionality?
0 commentaires
Cette question est clôturée.
Voir également
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!