Re: [R] Fast Two-Dimensional Optimization

2010-11-27 Thread Wonsang You
Dear Dave,

Thank you for your recommendation. I looked over the website of AD Model
Builder for fast optimization. I want to ask you whether the software can be
used in R programming as a kind of R package? Or is there any possibility
that it can be jointly used with R packages?

Regards,
Wonsang


2010/11/25 dave fournier da...@otter-rsch.com

 Hi,

 You should be able to get the performance you want with AD Model Builder
 which is free software available at

  http://admb-project.org

 I can advise you if you are interested.

  Cheers,

Dave


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Re: [R] Fast Two-Dimensional Optimization

2010-11-25 Thread Wonsang You
Thank you for your kind comments.
I tried different algorithms such as BFGS, CG, and so on. However, the
choice of algorithms was not effective on reducing computation time.

Instead, your second suggestion of coding the gradient of minimization
function was a little bit successful to reduce computation time. It was
twice faster than before. I appreciate you for your help.


2010/11/22 Rubén Roa r...@azti.es

 Did you try different algorithms? optim has Nelder-Mead (default), BFGS,
 simulated annealing, CG, etc.
 Depending on your problem, they can be much faster than the default.
 See
 ?optim
 and check the info for 'method'

 Check also optimx, a new wrapper for optim that can try out all methods.

 Another approach that may speed up calculations is to code for the
 gradients of the function that you're minimizing.
 Check argument 'gr' of optimx.

 HTH


 

 Dr. Rubén Roa-Ureta
 AZTI - Tecnalia / Marine Research Unit
 Txatxarramendi Ugartea z/g
 48395 Sukarrieta (Bizkaia)
 SPAIN



  -Mensaje original-
  De: r-help-boun...@r-project.org
  [mailto:r-help-boun...@r-project.org] En nombre de Wonsang You
  Enviado el: lunes, 22 de noviembre de 2010 16:17
  Para: r-help@r-project.org
  Asunto: [R] Fast Two-Dimensional Optimization
 
 
  Dear R Helpers,
 
  I have attempted optim function to solve a two-dimensional
  optimization problem. It took around 25 second to complete
  the procedure.
  However, I want to reduce the computation time: less than 7
  second. Is there any optimization function in R which is very rapid?
 
  Best Regards,
  Wonsang
 
 
  -
  Wonsang You
  Leibniz Institute for Neurobiology
  --
  View this message in context:
  http://r.789695.n4.nabble.com/R-Fast-Two-Dimensional-Optimizat
  ion-tp3053782p3053782.html
  Sent from the R help mailing list archive at Nabble.com.
 
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[R] Fast Two-Dimensional Optimization

2010-11-22 Thread Wonsang You

Dear R Helpers,

I have attempted optim function to solve a two-dimensional optimization
problem. It took around 25 second to complete the procedure.
However, I want to reduce the computation time: less than 7 second. Is there
any optimization function in R which is very rapid?

Best Regards,
Wonsang


-
Wonsang You
Leibniz Institute for Neurobiology
-- 
View this message in context: 
http://r.789695.n4.nabble.com/R-Fast-Two-Dimensional-Optimization-tp3053782p3053782.html
Sent from the R help mailing list archive at Nabble.com.

[[alternative HTML version deleted]]

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Re: [R] Fast Two-Dimensional Optimization

2010-11-22 Thread Ben Bolker
Wonsang You you at ifn-magdeburg.de writes:

 I have attempted optim function to solve a two-dimensional optimization
 problem. It took around 25 second to complete the procedure.
 However, I want to reduce the computation time: less than 7 second. Is there
 any optimization function in R which is very rapid?

  This is not nearly enough information for us to help. The answer
depends on the characteristics of your objective function.  You may be
able to quadruple the speed of your optimization by coding your objective
function more efficiently in R or by re-coding it in C or C++. You may
be able to choose better starting conditions.  You may be able to pick
an optimization method that is more suitable for your objective function
(see ?optim and the optimx package on r-forge).

  Ben Bolker

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