>>>>> "NSW" == Nathan S Watson-Haigh <nathan.watson-ha...@csiro.au>
>>>>> on Wed, 7 Jan 2009 12:45:50 +1000 writes:
NSW> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
NSW> andrew wrote:
>> the SparseM package might be what you are looking for
>>
>> http://www.econ.uiuc.edu/~roger/research/sparse/SparseM.pdf
>>
>> On Jan 7, 11:36 am, Søren Højsgaard
>> <soren.hojsga...@agrsci.dk> wrote:
>>> You can do mat[lower.tri(mat, diag=F)] Søren
>>>
NSW> Thanks, although my matrices are dense and not
NSW> sparse. I have however, found the Matrix package:
NSW> http://cran.r-project.org/web/packages/Matrix/index.html
NSW> The dspMatrix class, seems like what I might want:
NSW> dspMatrix - Symmetric real matrices in packed storage
NSW> (one triangle only)
NSW> I'm just trying to test it out with my usual 24k x 24k
NSW> size matrices.
Good; I was just about to propose using 'Matrix'.
Note that 'Matrix' is a 'Recommended' package in "R-devel" aka
"R 2.9.0 Under development (unstable).
As a co-maintainer of the package, I'm biased of course, but
also extremely interested in feedback / questions from users
like you, about missing features, unclear documentation,
possible bugs, ...
Regards,
Martin Maechler, ETH Zurich
>>> ________________________________
>>>
>>> Fra: r-help-boun...@r-project.org på vegne af Nathan
>>> S. Watson-Haigh Sendt: on 07-01-2009 01:28 Til:
>>> r-h...@r-project.org Emne: [R] Memory Efficiency of
>>> Symmetric Matrix
>>>
>> I'm generating a symmetric correlation matrix using a
>> data matrix as input: mat <- cor(data.mat)
>>
>> My question is: Is there a more memory efficient way to
>> store this data? For instance, since: all(mat == t(mat))
>> every value is duplicated, and I should be able to almost
>> half the memory usage for large matrices.
>>
>> Any thoughts/comments?
>>
>> Cheers, Nathan
>>
NSW> - -- -
NSW> --------------------------------------------------------
NSW> Dr. Nathan S. Watson-Haigh OCE Post Doctoral Fellow
NSW> CSIRO Livestock Industries Queensland Bioscience
NSW> Precinct St Lucia, QLD 4067 Australia
NSW> Tel: +61 (0)7 3214 2922 Fax: +61 (0)7 3214 2900 Web:
NSW> http://www.csiro.au/people/Nathan.Watson-Haigh.html -
NSW> --------------------------------------------------------
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