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Topic: Can this run any faster?
Replies: 36   Last Post: May 9, 2013 12:04 PM

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 Elnaz Sadeghian Posts: 206 From: Tehran, Iran Registered: 5/26/07
Can this run any faster?
Posted: Apr 9, 2013 6:30 PM

Hi all,
Is there any way to make this excerpt of the code run faster?
In my script I call the function including this loop many times and "length" is in the order of 30K or more. "transitions" is a stored 32 by 4 matrix.
I have turned that function into C and am using it as a mex file but it's still prohibitively slow.
Using tic-toc I see that this loop is the most time consuming loop in that function. Is there anyway to make this run faster?

a=zeros(16,length);
a=a-inf;
a(1,1)=0;
for i= 2:length
for j= 1:32
A = a(transitions(j,2),i);
B = a(transitions(j,1),i-1) + ug(j, i-1) + eg(j, i-1);
if(A == -inf && B == -inf)
a(transitions(j,2),i) = -inf;
else
a(transitions(j,2),i) = max(A,B) + log(1+exp(-abs(A-B)));
end
end
end

Thanks,
Elnaz

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