From: Prof Brian Ripley <ripley_at_stats.ox.ac.uk>

Date: Thu 14 Jul 2005 - 21:29:25 EST

Date: Thu 14 Jul 2005 - 21:29:25 EST

On Thu, 14 Jul 2005, Kenneth Cabrera wrote:

> Thank you Dr. Spencer Graves for your answer.

*>
**> What kind of matrices? They come form an image of about 3000x5000, and
**> I need to generate arround 1024 matrices of the same size, they are not
**> sparse
**> matrices.
**>
**> What function can I use to, once generated one matrix, I could save into disk
**> and then use the same space for the following, and so on.
*

You can use either save or .saveRDS/serialize followed by rm() and gc(). You cannot use the same space, but you can free up the space.

Then when you need the data again, load/.readRDS/unserialize can pull the object back. (If you arrange this right the object will only go into a temporary frame and so only be needed one at a time.)

*>
*

> Thank you very much for your help

*>
**> Kenneth
**>
**> Spencer Graves wrote:
**>
**>> What kinds of matrices? There are facilities in the Matrix and
**>> SparseM packages that might help for sparse matrices. If they are N x k
**>> where N is large and k is not, can you compute something like the QR
**>> decomposition and get away with keeping only the R part for most of your
**>> matrices?
**>>
**>> One could potentially define a class of matrices that are only kept
**>> in memory only when needed; I think S-Plus may do that. It would take a
**>> lot of work to make that work generally, but you might be able to
**>> accomplish what you need with a much smaller effort.
**>>
**>> spencer graves
**>>
**>> Kenneth Roy Cabrera Torres wrote:
**>>
**>>
**>>> Hi R users and developers:
**>>>
**>>> I want to know how can I save memory in R
**>>> for example:
**>>> - saving on disk a matrix.
**>>> - using again the matrix (changing their values)
**>>> - saving again the matrix on disk in a different file.
**>>>
**>>> The idea is that I have a process that generate several
**>>> matrices, but if I keep them all in memory it will overflow.
**>>>
**>>> How can I save them in different files, so I use the same
**>>> amount of memory for each processed matrix?
**>>>
**>>> Thank you for your help.
**>>>
**>>>
**>>
**>>
**>
*

-- Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.htmlReceived on Thu Jul 14 21:36:33 2005

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