update.ff {ff} | R Documentation |
update
copies updates one ff object with the content of another object.
update.ff(object, from, delete = FALSE, bydim = NULL, fromdim = NULL, BATCHSIZE = .Machine$integer.max, BATCHBYTES = getOption("ffbatchbytes"), VERBOSE = FALSE, ...)
object |
an ff object to which to update |
from |
an object from which to uodate |
delete |
TRUE to delete the 'from' object after the update, can speed up updating significantly |
bydim |
how to interpret the content of the object, see ff |
fromdim |
how to interpret the content of the 'from' object, see ff |
BATCHSIZE |
BATCHSIZE |
BATCHBYTES |
BATCHBYTES |
VERBOSE |
VERBOSE |
... |
further arguments |
If the source object is.ff
and delete=TRUE
then instead of slow copying we swap and rename the files behind the ff objects.
a copy of the input ff object
Jens Oehlschlägel
ff
, clone
, ffvecapply
, vectorCompatible
x <- ff(1:100) y <- ff(-(1:100)) filename(x) filename(y) update(x, from=y) update(x, from=y, delete=TRUE) filename(x) x ## Not run: cat("timings\n") x <- ff(1:10000000) y <- ff(-(1:10000000)) system.time(update(x, from=y)) system.time(update(x, from=y, delete=TRUE)) ## End(Not run)