R memory management / cannot allocate vector of size n Mb

Question

I am running into issues trying to use large objects in R. For example:

> memory.limit(4000)
> a = matrix(NA, 1500000, 60)
> a = matrix(NA, 2500000,         


        

Answer 1

I followed to the help page of memory.limit and found out that on my computer R by default can use up to ~ 1.5 GB of RAM and that the user can increase this limit. Using the following code,

>memory.limit()
[1] 1535.875
> memory.limit(size=1800)

helped me to solve my problem.

Answer 2

The save/load method mentioned above works for me. I am not sure how/if gc() defrags the memory but this seems to work.

# defrag memory 
save.image(file="temp.RData")
rm(list=ls())
load(file="temp.RData")