Re: [R] load ing and saving R objects

From: Roger D. Peng <rpeng_at_jhsph.edu>
Date: Tue 14 Jun 2005 - 23:38:27 EST

I would suggest saving each object to an individual file with some sort of systematic file name. That way, you can implement a   rudimentary key-value database and load only the objects you want. You might be interested in the 'serialize()' and 'unserialize()' functions for this purpose.

If having ~15000 files is not desirable, then you need a database like GDBM. If you can live with something simpler, you might take a look at my 'filehash' package at http://sandybox.typepad.com/software/. It hasn't been tested much but it may suit your needs.

-roger

Richard Mott wrote:
> Does anyone know a way to do the following:
>
> Save a large number of R objects to a file (like load() does) but then
> read back only a small named subset of them . As far as I can see,
> load() reads back everything.
>
> The context is:
>
> I have an application which will generate a large number of large
> matrices (approx 15000 matrices each of dimension 2000*30). I can
> generate these matrices using an R-package I wrote, but it requires a
> large amouint of memory and is slow so I want to do this only once.
> However, I then want to do some subsequent processing, comprising a very
> large number of runs in which small (~ 10) random selection of matrices
> from the previously computed set are used for linear modeling. So I
> need a way to load back named objects previously saved in a call to
> save(). I can;t see anyway of doing this. Any ideas?
>
> Thanks
>
> Richard Mott
>
>

-- 
Roger D. Peng
http://www.biostat.jhsph.edu/~rpeng/

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Received on Tue Jun 14 23:43:03 2005

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