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Memory allocation
3 messages · Gabriel Margarido, Duncan Murdoch, Keith Ponting
On 1/16/2009 12:46 PM, Gabriel Margarido wrote:
Hello everyone,
I have the following issue: one function generates a very big array (can be
more than 1 Gb) and returns a few variables, including this big one. Memory
allocation is OK while the function is running, but the final steps make
some copies that can be problematic. I looked for a way to return the values
without copying (even tried Rmemprof), but without success. Any ideas?
The code looks like this:
myfunc <- function() {
...
bigarray <- ...
...
final <- list(..., bigarray=bigarray, ...)
class(final) <- "myfunc"
final
}
Thank you in advance,
I believe this will do less copying, but I haven't profiled it to be
sure. Replace the last three lines with this one statement:
structure(list(..., bigarray=bigarray, ...),
class = "myfunc")
If that doesn't help, then you really need to determine where the
copying is happening: you can use Rprofmem() to do that.
Duncan Murdoch
2 days later
Gabriel Margarido <gramarga <at> gmail.com> writes:
... I looked for a way to return the values without copying (even tried Rmemprof), but without success. Any ideas? ...
I solved similar problems using the R.oo package, which emulates pass-by-reference semantics in 'R'. HTH Keith