memory managment under Windows XP
On Thu, 23 Feb 2006, roger bos wrote:
And of course using rm(...) to clean up objects you no longer need. No amount of physical memory can save you from grossly inefficient code and large memory leaks. For example, lets say I have a large testMat object that I use time period. I loop though each month using for loops. Even though the object has the same name each month, and thus gets overwritten, the memory management seems to go better by manually removing the object at the end of each loop. Also, I sometimes call gc() at the end of each loop, but I don't know if that actually helps or not. I figure it can't hurt.
It does help to rm() and then gc() at a point when you know that the number of objects in use is minimal. R will gc() repeatedly when it starts to run out of address space, but this does not help if the address space is already fragmented. The main problem on 32-bit OSes is (virtual) memory fragmentation, and 3Gb is not really much address space for objects in 100s of Mb. I've now only got a 64-bit desktop and servers (plus a 32-bit Windows laptop). It is a shame for Windows users that a 64-bit Open Source toolchain* is nowhere in sight, but I suspect a sufficiently determined user of Win64 could build a 64-bit port of R with commercial compilers. *You need a compiler, assembler, linker and runtime, and the latter may well be the most problematic.
On 2/23/06, Liaw, Andy <andy_liaw at merck.com> wrote:
There are plenty in the the list archive, one of which is to switch to a run 64-bit R on a 64-bit platform with lots of physical RAM. Such hardware is quite affordable these days (certainly cheaper than most commercial software that you'd have to buy if you didn't have R). Andy From: r user
I am using R 2.2.1 in a Windowes XP environment. I work with very large datasets, and occassionally run out of memory. I have modified my boot.ini file to use the "/3gb switch". I also run the following line after I launch R ( I am unsure if it is helpful). "memory.limit(size = 4095)" Please point me to useful references on how to better manage memory, or suggestother actions.
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Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595