programmatically shift between %do% and %dopar% in foreach?

I'd like to have the option of using foreach but be able to restrict
processing to be parallel in one of my packages.

I'd rather not have

  x <- if(goParallel) foreach(stuff) %dopar% foo else foreach(stuff) %do%
foo

Also, the function is nested within layers that conduct parallel processing
(i.e. the foo above might also use dopar inside) and my impression is
that registerDoSEQ would shut down parallel processing for both functions.

It looks like %do% and %dopar% are not existing objects:

str(%do%)
  Error: unexpected SPECIAL in "str(%do%"

They are simply functions - you just forgot to quote it:
str(`%do%`)
function (obj, ex)  

%...% are binary infix operators so if you use them as a symbol, you have to quote them.
Otherwise I would add some conditional logic to switch between them such as

  operator <- if(goParallel) %dopar% else %do%
   x <- foreach(stuff) operator foo

It works, but if you want to keep the infix notation you have to use something like

`%op%` <- if (goParallel) `%dopar%` else `%do%`

otherwise for your suggestion you'd have to use the functional form:

operator(foreach(stuff), foo)

Cheers,
Simon
Thanks,

Max

sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] foreach_1.4.0

loaded via a namespace (and not attached):
[1] codetools_0.2-8 iterators_1.0.6

	[[alternative HTML version deleted]]

_______________________________________________
R-sig-hpc mailing list
R-sig-hpc at r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-hpc

programmatically shift between %do% and %dopar% in foreach?

Thread (3 messages)