Parallel apply function used to perform the same operation over all the
elements of data objects like matrices, data frames or lists. This function
provides a parallel implementation of both the apply() and lapply() functions
from the core of the R programming language. This parallel implementation
papply() has been extended to accept an ff object as input which allows the
processing of much larger data stored on disk.
vector indicating which elements of the matrix the function
will be applied to. The default value is 1 and indicates the
rows, 2 indicates the columns and the parameter is ignored
if data is a list
out_filename
string, name of the result file when input is an ff
object
Details
The function to be applied can be supplied to papply() either as a function
name or as a function definition. When only the function name is provided,
the package implementing the function has to be loaded before the SPRINT
library is initialised in order to ensure that the name is recognised by all
the processes involved in the computation.