[Rd] modifying large R objects in place

Petr Savicky savicky at cs.cas.cz
Thu Sep 27 15:51:51 CEST 2007


In my previous email, I sent the example:
>   a <- matrix(as.integer(1),nrow=14100,ncol=14100) # 774m
>   a[1,1] <- 0 # 3.0g
>   gc() # 1.5g

This is misleading. The correct version is
   a <- matrix(as.integer(1),nrow=14100,ncol=14100) # 774m
   a[1,1] <- as.integer(0) # 1.5g
   gc() # 774m

So, the object duplicates, but nothing more.

The main part of my previous email (question concerning
a possible bug in the behavior of nrow(a) and ncol(a))
remains open.

Petr Savicky.



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