rtape-sub-apply: Iterate over tape, discarding results.

In rtape: Manage and manipulate large collections of R objects stored as tape-like files

Description

Iterate over tape, discarding results.

Usage

rtape_apply(fNames, FUN, ...)

Arguments

fNames	Name of the tape file to read; if this argument is a vector of several names, function behaves as reading a single tape made of all those tapes joined in a given order.
FUN	Callback function.
...	Additional parameters to FUN.

Details

This function read the tape from the oldest to the newest writes and executes the callback function on each read object. Logically, it is an equivalent to ignore<-lapply(rtapeAsList(fName),FUN,...), but it is optimized to store only the currently processed object in the memory and to discard FUN results as soon as they appear.

Author(s)

Miron B. Kursa [e-mail]

Examples

unlink('tmp.tape')
#Record something on the tape
rtapeAdd('tmp.tape',runif(3))
rtapeAdd('tmp.tape',rnorm(3))

#Print tape contents
rtape_apply('tmp.tape',print)
unlink('tmp.tape')

rtape documentation built on May 2, 2019, 9:18 a.m.