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very very very slow computing
From: |
Depo |
Subject: |
very very very slow computing |
Date: |
Fri, 6 Feb 2009 08:04:47 -0800 (PST) |
Hi everybody,
I was just trying making some simple operations on a large matrix (10, 3000)
and I faced off o very slow computational time comparing to the simple
operation I was attempting to do. Looking for the problem I saw that even
copying same values to a new matrix was a computationally huge
operation!!!!!!!!!!!!!
That is the code:
clear new_sign_difference; #to ensure
it is emty
i=1; k=1;
while (k <= n_rows) #I have
used while statement instead of for because some says it is faster...
while (i <= n_cols)
new_sign_difference(k,i)=sign_difference(k,i) #reassign same
values to a new matrix
disp(i);
disp(k);
i++;
endwhile
k++; i=1;
endwhile
the matrix sign_difference has size 10x3'000, so this is a 30'000-operation
loop. It takes up to 10
minutes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If I only visualize on screen matrix' values it takes 1
second............................., here is the code:
clear new_sign_difference;
i=1; k=1;
while (k <= n_rows)
while (i <= n_cols)
sign_difference(k,i) #only to screen, without writing on a
new matrix
disp(i);
disp(k);
i++;
endwhile
k++; i=1;
endwhile
How is it possible?????????????????????????????????????
Please help me, I'm getting crazy and I can't work at all at these
conditions..........................
Tanks everybody
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- very very very slow computing,
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