Memory Efficiency of Symmetric Matrix

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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, S?ren H?jsgaard <Soren.Hojsga... at agrsci.dk> wrote:
You can do
mat[lower.tri(mat, diag=F)]
S?ren

Thanks, although my matrices are dense and not sparse. I have however, found the Matrix package:
http://cran.r-project.org/web/packages/Matrix/index.html

The dspMatrix class, seems like what I might want:
dspMatrix - Symmetric real matrices in packed storage (one triangle only)

I'm just trying to test it out with my usual 24k x 24k size matrices.
________________________________

Fra: r-help-boun... at r-project.org p? vegne af Nathan S. Watson-Haigh
Sendt: on 07-01-2009 01:28
Til: r-h... at 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

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PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
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______________________________________________
R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
- --
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Dr. Nathan S. Watson-Haigh
OCE Post Doctoral Fellow
CSIRO Livestock Industries
Queensland Bioscience Precinct
St Lucia, QLD 4067
Australia

Tel: +61 (0)7 3214 2922
Fax: +61 (0)7 3214 2900
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Memory Efficiency of Symmetric Matrix

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