Re: [R] Help with Matrix package

From: rob foxall (IFR) <>
Date: Thu 13 Oct 2005 - 20:39:12 EST

Thanks Prof. Ripley for your prompt reply. With regards to Rblas.dll my current situation is that I have taken the Rblas.dll from CRAN: contrib/ATLAS/P4/, and replaced the default Rblas.dll in my R /bin with this one.



-----Original Message-----
From: Prof Brian Ripley [] Sent: 13 October 2005 11:33
To: rob foxall (IFR)
Subject: Re: [R] Help with Matrix package

The first thing is to ensure that you are using an optimized BLAS. On Windows, use Goto's BLAS if you have it (is not currently available and redistribution is not allowed) or one of the pre-built ATLAS-based Rblas.dll on CRAN or (best of all) optimize your own build of ATLAS.

The Matrix package depends on an optimized BLAS even more crucially than

base R.

On Thu, 13 Oct 2005, rob foxall (IFR) wrote:

> Hello all,
> A colleague at work set me the challenge to convert some MATLAB
> code into R, to see which is faster. We'd seen that benchmark
> MATLAB 6.5 to R1.90 (and others), and so I thought that I should be
> to get roughly comparable speeds. The code has lots of multiplications
> of matrixes, transposes, and MATLAB's "repmat". I did the code
> conversion, and R was about 6 times slower, so I had a closer look at
> the benchmark comparison and it seems that I should be using the
> "Matrix" package.
> Is there any dummies-level help available for this package? I am
> struggling even to apply simple functions such as "sum" and "mean" to
> matrixes constructed from this class (not that I need to yet), and
> importantly "kronecker", to convert from "repmat". (The help for
> "kronecker" from the Matrix package doesn't seem to mention kronecker,
> so I am a bit stuck). Any guidance greatly accepted -- I have read the
> overview, looked through the various Matrix-listed functions, and
> unsuccessfully tried searching R-help.
> Using R version 2.2.0, windows xp.

Brian D. Ripley,        
Professor of Applied Statistics,
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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