How can I make this code run faster?
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Conrado Neto
il 25 Ago 2020
Commentato: Conrado Neto
il 26 Ago 2020
This code takes about 30s to run, and I will need to run it several times
Can anyone help me make it faster?
here is the code:
sum_Load = rand(1,1000); % For demonstration purposes
Pseudo_Load_Factor = rand(500,1000); % For demonstration purposes
Disp_Factor = rand(500,1000); % For demonstration purposes
M = 1000;
N = 500;
Disp_Inter = zeros(M,N);
for j = 1:M
Load_Inter = sum_Load(j);
for i = 1:N
idx = find(cummin(Pseudo_Load_Factor(i,:))<Load_Inter & cummax(Pseudo_Load_Factor(i,:))>Load_Inter,1,'first');
if isempty(idx)
Disp_Inter(j,i) = 0.10*7000;
else
Disp_Inter(j,i) = interp1(Pseudo_Load_Factor(i,(idx-1):idx),Disp_Factor(i,(idx-1):idx),Load_Inter);
end
end
end
Thanks a lot!!
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Risposta accettata
Bruno Luong
il 25 Ago 2020
Modificato: Bruno Luong
il 25 Ago 2020
M = 1000;
N = 500;
P = 1000;
sum_Load = rand(1,M); % For demonstration purposes
Pseudo_Load_Factor = rand(N,P); % For demonstration purposes
Disp_Factor = rand(N,P); % For demonstration purposes
Disp_Inter = zeros(M,N);
for j = 1:M
Load_Inter = sum_Load(j);
A = Pseudo_Load_Factor-Load_Inter;
B = A(:,1:end-1).*A(:,2:end) < 0;
[Bm,idx] = max(B,[],2);
idxl = (1:N)'+(idx-1)*N;
idxr = idxl+N;
PLFR = Pseudo_Load_Factor(idxr);
w = (PLFR-Load_Inter)./(PLFR-Pseudo_Load_Factor(idxl));
DPI = w.*Disp_Factor(idxl) + (1-w).*Disp_Factor(idxr);
DPI(Bm==0) = 700;
Disp_Inter(j,:) = DPI;
end
5 Commenti
Bruno Luong
il 25 Ago 2020
Yes it's the firstpoint (the idx returned by MAX command is the first one). Otherwise mine result won't match yours.
Più risposte (1)
Steven Lord
il 25 Ago 2020
I have some off the top of my head suggestions that come from the structure of the code, but if you explain in words what Disp_Inter represents and/or the underlying problem you're trying to solve we may be able to suggest functions to help improve your algorithm and/or its implementation at a higher level.
%snip
for j = 1:M
Load_Inter = sum_Load(j);
for i = 1:N
idx = find(cummin(Pseudo_Load_Factor(i,:))<Load_Inter & cummax(Pseudo_Load_Factor(i,:))>Load_Inter,1,'first');
An obvious low-hanging fruit: since Pseudo_Load_Factor doesn't change inside the nested loops, compute the cumulative minimum and cumulative maximum of them once before entering the loop and index into those precomputed matrices inside the loop.
if isempty(idx)
Disp_Inter(j,i) = 0.10*7000;
Preallocate Disp_Inter to this constant value before the loop (though I'd use 700 rather than multiplying the integer value 7000 by the double precision approximation to one tenth.) That way you only need to change the value if idx is not empty.
%snip the rest of the code
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