Question

I am using ‘mem.limits’ to restrict the memory limit of an R process. E.g:

mem.limits(500000, 20000000)
gc() #see limits
x <- rnorm(1e8); #should fail

This still works fine, however since R 2.14 there is a warning message:

Warning message: ‘mem.limits’ is deprecated. Use ‘gc’ instead. See
help(“Deprecated”)

Now I am not sure what to do with this. How is the garbage collection related to setting a memory limit?

Answer 1

In R 2.14.x they are deprecated but still functional:

> R.version.string
[1] "R version 2.14.0 (2011-10-31)"
> mem.limits(500000, 20000000)
nsize vsize 
5e+05 2e+07 
Warning message:
'mem.limits' is deprecated.
Use 'gc' instead.
See help("Deprecated") 
> gc() #see limits
         used (Mb) gc trigger (Mb) limit (Mb) max used (Mb)
Ncells 170754  9.2     350000 18.7       26.8   350000 18.7
Vcells 272683  2.1     905753  7.0       19.1   851886  6.5
> x <- rnorm(1e8); #should fail
Error: vector memory exhausted (limit reached?)

In R-devel all limits are defunct. The functionality has been removed with no replacement. See NEWS for R 2.14.0 and PR#14795 for details.