Making a code runs faster
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How can I make the following code runs faster (This a part of a larger code). I do not want to use parfor.
for rotation=1:360
RHO(:,1)=(CL*Landa)./T(tnum).LoAn(:,1);
THETA=T(tnum).LoAn(:,3);
X(:,1)=RHO.*cos(deg2rad(THETA(:,1)+rotation));
Y(:,1)=RHO.*sin(deg2rad(THETA(:,1)+rotation));
XP=round(72+X);
YP=round(72+Y);
mat=zeros(144,144);
for i=1:size(XP,1)
a=XP(i,1);
b=YP(i,1);
if a>0 & a<145 & b>0 & b<145
mat(a,b)= T(tnum).LoAn(i,2);
end
end
end
2 commentaires
Walter Roberson
le 2 Sep 2013
Isn't your RHO the same for each iteration? If so then compute it outside the loop. Same for THETA.
To confirm: LoAn is a 2D array, and not just a row vector ? so size(LoAn,1) > 1 ?
Roger Stafford
le 2 Sep 2013
It looks as though your purpose in this code is to set up the array 'mat'. However, on each trip through the outer for-loop this array is completely erased and refilled with the information from the next 'rotation' angle. What is the sense in that? Only the last 360 degree angle would have any effect on the final values in 'mat'. Is it possible you are doing something with 'mat' which you haven't shown here before returning for another rotation angle? We need to know such things if we are to help you effectively.
Réponses (1)
Azzi Abdelmalek
le 2 Sep 2013
Modifié(e) : Azzi Abdelmalek
le 2 Sep 2013
You can start by pre-allocating
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