Re: [Quantlib-dev] Bermudan LLM

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On 24 August 2011 at 17:29, Daniel Cegiełka wrote:
| 
| 2011/8/24 Dirk Eddelbuettel <ed...@de...>
| 
| 
|     On 24 August 2011 at 16:17, Ferdinando Ametrano wrote:
|     | Hi Kakhkhor
|     |
|     | I apologize, I completely misinterpreted your question, my fault.
|     |
|     | As you wrote ATLAS would be problematic because in Windows it is
|     | available only if using cygwin, as far as I know. Besides it is plain
|     | C, isn't it?
| 
|     Atlas is one of several accelerated implementation of the BLAS.  It can
|     certainly be compiled with different Windows toolchains; there is eg a
|     binary
|     you can download for R which was built with MinGW (ie very much not Cygwin)
|     as R on Windows requires the MinGW toolchain.
| 
|     Commercial software (Matlab comes to mind) often bundles its own
|     accelerated
|     BLAS; Atlas happens to have the most liberal license (but Goto is now
|     'Open'
|     too as the original author moved on).
| 
| 
| Goto is probably one of the best implementations of BALS. Unfortunately, it is
| no longer being actively developed by Kazushige Goto. I give the address where
| you can find fresh updates.
| 
| http://prs.ism.ac.jp/~nakama/SurviveGotoBLAS2/

That are 'just' maintenance updates by Ei-Ji Nakama. The new and more
ambitious project I was referring to is on github:

   https://github.com/xianyi/OpenBLAS

but I have not tried it.

Dirk

| 
| 
|     | What about using uBLAS, the C++ boost implementation?
| 
|     AFAICT it is a pain to use, and the numerics wrapper for actual linear
|     algrebra was once again being rewritten when I last checked. It also falls
|     back to using a BLAS implementations.  FWIW I never managed to even cook
|     up a
|     simple linear regression 'from first principles' (eg using a SVD) with
|     uBlas.
| 
|     An alternative could be provided by Eigen (http://eigen.tuxfamily.org)
|     which
|     is very clever, very fast, very templated C++ --- and does not use BLAS!
|     But
|     it would add another build dependency which is a clear downside.
| 
| 
| I also thought about Eigen... but like you wrote, it means
| another dependency.
| 
| Best regards,
| daniel
| 
| 
|  
| 
| 
|     Another somewhat lighter alternative is Armadillo (http://arma.sf.net).
|     Also
|     templated, can use BLAS and a little simpler than Eigen. I quite like it --
|     and have written an package 'RcppArmadillo' that makes it a snap to use
|     this
|     from R, leveraging our Rcpp package also used to tie [parts of] QuantLib to
|     R
|     via RQuantLib.
| 
|     [ From all that, I have a number of competing 'FastLm' implementations of
|     linear model fits (ie. ordinary least squares) using Armadillo, Eigen and
|     GSL.  Armadillo does fine, Eigen does better and GSL is slowest. My blog
|     had
|     a few posts on that. ]
| 
|     | As you understand moving to uBLAS would be a major change anyway and
|     | to do it in a backward compatible way (i.e. not dropping support for
|     | QuantLib::Matrix, QuantLib::Array, etc.) would be even more
|     | challenging, so Luigi opinion on this will rule.
|     | Unfortunately as he gets older he's more and more conservative ;-)
|     |
|     | I for one would support a transition to uBLAS and removing all the
|     | QuantLib code that could be replaced by boost (e.g. math and stat
|     | functions), maybe on a QuantLib 2.x branch which would be not backward
|     | compatible with the 1.x branch
| 
|     That is probably a good design decision in the medium term but you may want
|     to really check viability of some of the required operations first.
| 
|     Hth,  Dirk
| 
|     | ciao -- Nando
|     |
|     | On Wed, Aug 24, 2011 at 12:37 AM, Kakhkhor Abdijalilov
|     | <kab...@gm...> wrote:
|     | > Longstaff-Schwartz method for Bermudan LLM requires OLS for every
|     | > early exercise opportunity, not just once.
|     | > I checked "Numerical recipes", Demel's and Golub's books and all
|     | > recommend not to use normal equations to solve OLS. Equity version of
|     | > Longstaff-Schwartz in QuantLib uses SVD too.
|     | >
|     | > The cost of SVD scales as SAMPLES*FACTORS^3, but the cost of path
|     | > generation scales as SAMPLES*FACTORS^2. SVD doesn't scale well as more
|     | > CPU cores are used, but path generation should scale almost perfectly.
|     | >
|     | > Regards,
|     | > Kakhkhor Abdijalilov.
|     | >
|     | >
|     ------------------------------------------------------------------------------
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|     |
|     |
|     ------------------------------------------------------------------------------
|     | EMC VNX: the world's simplest storage, starting under $10K
|     | The only unified storage solution that offers unified management
|     | Up to 160% more powerful than alternatives and 25% more efficient.
|     | Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev
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|     --
|     Two new Rcpp master classes for R and C++ integration scheduled for
|     New York (Sep 24) and San Francisco (Oct 8), more details are at
|     http://dirk.eddelbuettel.com/blog/2011/08/04#
|     rcpp_classes_2011-09_and_2011-10
|     http://www.revolutionanalytics.com/products/training/public/
|     rcpp-master-class.php
| 
|     ------------------------------------------------------------------------------
|     EMC VNX: the world's simplest storage, starting under $10K
|     The only unified storage solution that offers unified management
|     Up to 160% more powerful than alternatives and 25% more efficient.
|     Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev
|     _______________________________________________
|     QuantLib-dev mailing list
|     Qua...@li...
|     https://lists.sourceforge.net/lists/listinfo/quantlib-dev
| 
| 

-- 
Two new Rcpp master classes for R and C++ integration scheduled for 
New York (Sep 24) and San Francisco (Oct 8), more details are at
http://dirk.eddelbuettel.com/blog/2011/08/04#rcpp_classes_2011-09_and_2011-10
http://www.revolutionanalytics.com/products/training/public/rcpp-master-class.php