| 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)