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Re: Code optimization [message #75143 is a reply to message #75142]

Wed, 16 February 2011 12:51

pgrigis
Messages: 436
Registered: September 2007

Senior Member

On Feb 16, 3:38 pm, kisCA <ki...@hotmail.com> wrote:
> Hi there,
>
> I am trying, if it's possible to write thes lines in matrix formalism
> but it seems a bit tricky for me.
>
> FOR I=1,NUM DO BEGIN
> SUMI=0.
> FOR K=1,M1 DO BEGIN
> FOR J=1,M1 DO BEGIN
> SUMI=SUMI+COV(J-1,K-1)*CS(J-1,I-1)*CS(K-1,I-1)
> ENDFOR
> ENDFOR
> VAR_ALPHA(I-1)=SUMI*VAR_FACTOR(I-1)
> ENDFOR
>
> Is anyone got an idea it will be welcome
>
> Cheers

Yeah, it looks like that doesn't really need loops...

First you want to replace the inner loop with a matrix
multiplication of COV and CS - call the result R (make
sure you get the row and columns in the proper order).
Then you want to replace the K loop with total(R*CS,1).
Then you want to replace the I loop with a multiplication
of the last result by var_factor.

Something along those lines should work...

Ciao,
Paolo

Ciao,
Paolo

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[Message index]

		Re: Code optimization By: Jeremy Bailin on Thu, 17 February 2011 11:52
		Re: Code optimization By: kisCA on Thu, 17 February 2011 11:42
		Re: Code optimization By: Fabzou on Thu, 17 February 2011 01:14
		Re: Code optimization By: Jeremy Bailin on Wed, 16 February 2011 13:48
		Re: Code optimization By: kisCA on Wed, 16 February 2011 13:25
		Re: Code optimization By: kisCA on Wed, 16 February 2011 13:23
		Re: Code optimization By: Jeremy Bailin on Wed, 16 February 2011 12:57
		Re: Code optimization By: pgrigis on Wed, 16 February 2011 12:51
		Re: Code optimization By: Kenneth P. Bowman on Thu, 17 February 2011 12:52
		Re: Code optimization By: pgrigis on Thu, 17 February 2011 12:09

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