This page documents the functions pmm for parallelized matrix
multiplication and the function control.pmm, which controls
the behaviour of pmm and other functions that execute tasks in
parallel.
a list of with the arguments ncores, f, and
sfstop or a function such as control.pmm that generates such
a list.
ncores
number (integer, default 1) of cores used for parallelized
matrix multiplication.
max.ncores
maximum number of cores (integer, default all cores of
a machine) used for parallelized computations.
f
number (integer, default 2) of tasks assigned on non-Windows OS
to each core in parallelized matrix multiplication.
sfstop
logical controlling whether the SNOW socket cluster is
stopped after each parallelized matrix multiplication on windows OS
(default FALSE).
allow.recursive
logical controlling whether nested parallelized
computation should be allowed (default TRUE).
...
further arguments, currently not used.
Details
Parallelized matrix multiplication shortens computing time for large data
sets (n>1000). However, the spawning of child processes requires
itself ressources and increasing the number of cores for parallel matrix
multiplication and evaluation of estimating equations/gradient does not
always result in reduced computing time. A sensible default for the number
of cores assigned to both tasks is likely
ncores=2.
max.ncores controls how many child processes are spawned in total
for both tasks. This can be used to prevent that child processes spawn
themselves children which may result in a considerable number of child
processes.
Value
pmm:
the matrix product A %*% B,
control.pmm:
a list with components
ncores, max.ncores, f,
sfstop, allow.recursive.
providing 
.