[R] R vs S-PLUS with regard to memory usage

[Anantha Prasad/NE/USDAFS]

Worked like magic thanks (I thought more I can allocate the better since my
application does not know before hand what the datasize is going to be)....
however, the step() function ran out of heap memory even after I allocated
15 MB ..... so, it looks like it is a no-win situation.....If I increase
heap too much to satisfy step(), there is disk swapping (if not on my
present machine, on others which do not have the luxury of 192 MB); if I
don't it runs out of memory.... any suggestions other than wait for 1.2? If
there are more people like me, it's some incentive to get 1.2 out soon!
Thanks much.
Prasad

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                    Peter Dalgaard                                                     
                    BSA                     To:     "Anantha Prasad/NE/USDAFS"         
                    <p.dalgaard at bios        <aprasad at fs.fed.us>                        
                    tat.ku.dk>              cc:     r-help at stat.math.ethz.ch           
                    Sent by:                Subject:     Re: [R] R vs S-PLUS with      
                    pd at blueberry.kub        regard to memory usage                     
                    ism.ku.dk                                                          
                                                                                       
                                                                                       
                    10/02/00 04:20                                                     
                    PM                                                                 
                                                                                       
                                                                                       



"Anantha Prasad/NE/USDAFS" <aprasad at fs.fed.us> writes:

> I am trying to translate code from S-PLUS to R and R really struggles!
> After starting R with the foll.
> R --vsize 50M --nsize 6M --no-restore
> on a 400 MHz Pentium with 192 MB of memory running Linux (RH 6.2),
> I run a function that essentially picks up an external dataset with 2121
> rows
> and 30 columns and builds a lm() object and also runs step() ... the step
()
> takes forever to run...(takes very little time in S-PLUS).

Notice that the --nsize takes the number of *nodes* as the value. Each
is 20 bytes, so you're allocating a 170MB chunk there. With various
other memory eaters active, that could easily push a 192MB machine
into thrashing.

The upcoming 1.2 version will be much better at handling memory, but
for now maybe reduce the nsize a bit? The vsize looks a bit hefty as
well given that the data should take up on the order of half a MB.

--
   O__  ---- Peter Dalgaard             Blegdamsvej 3
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907




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