raster package

I have to reclassify a large (> 8000x8000 pixels) geotif raster. I normally
would do it through grass (or saga) but would like to try the raster
package in R.
The problem is that I'm a bit confused on how to do it. My understanding
of the package
is that it provides a way to operate in the rasters by pieces, not having
to read the whole thing into memory. I've seen there's a function reclass()
but how do I actually read the raster? If I use readAll() this is going
to be as
using readGDAL() directly, so this is not the way. Do I have to use
a for() of readRows(), then reclass()? This seems a bit low-level. Is
there a way
of assigning the tif file to an R raster object and then just use
reclass() and R would
read the file by pieces as needed? That's what I would like to...

Agus


-------------- next part --------------
A non-text attachment was scrubbed...
Name: alobolistas.vcf
Type: text/x-vcard
Size: 251 bytes
Desc: not available
URL: <https://stat.ethz.ch/pipermail/r-sig-geo/attachments/20090518/5166a0ea/attachment.vcf>