[Scilab-users] More rapid calculation

[Stéphane Mottelet]

Le 15/02/2018 à 00:02, fujimoto2005 a écrit :
> Sorry, my code contains line "exec user file "
> I attached revised version which contains the line as a user function.
> Please see it.
>
> Best regards
>
> corSmplebaseZ1andZ2_with_UserFunc.sce
> <http://mailinglists.scilab.org/file/t497065/corSmplebaseZ1andZ2_with_UserFunc.sce>
>
>
>
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Hello,

In your code, most of the cpu time is spent between lines 40-54 (random 
generation of big matrices), then between lines 54-60, where one of the 
bottlenecks is the use of repmat (and you use it twice) and the 
"cumsum".In previous posts of Heinz Nabielek related to code 
optimization, you may have noticed that using matrix multiplication by a 
vector of ones gives the same result BUT uses the BLAS ! For example, 
compare these timings, with size(timePoints_V)=[1 25000] and sample=5000) :

tic;repmat(timePoints_V,2*sample,1);disp(toc())

    12.372273

tic;ones(2*sample,1)*timePoints_V;disp(toc())

    1.823105

On my machine (MacPro, OSX, Scilab 6.0.0), this last piece of code uses 
100% cpu (four cores).

S.

-- 
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet