Re: Time management in S-Plus

[<Bill.Venables@csiro.au>]

 

How are you doing the iterations?  Are you using a for-loop or are you using a batch script with the loop unrolled into explicit code?  I have found that the latter can be very effective for large calculations.  The technique is essentially to get S-PLUS itself to do the unrolling by language manipulatons, sink the result to a file and then use the file as a batch script. 

 

Bill Venables.

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From: s-news-owner@lists.biostat.wustl.edu [mailto:s-news-owner@lists.biostat.wustl.edu] On Behalf Of Herschtal Alan
Sent: Monday, 4 June 2007 11:24 AM
To: s-news@lists.biostat.wustl.edu
Subject: [S] Time management in S-Plus

I am trying to run many iterations of a simulation in S-plus, and am finding that the time taken per iteration increases almost exponentially. I have tried to write the code as efficiently as I can, with minimal use of for loops, vector arithmetic wherever possible, and reusing datasets where feasible. I understand that this phenomenon has something to do with the paging in S-plus's memory management system. Is there any way to keep the execution time constant ?

Thanks,

Alan Herschtal
Biostatistician
Centre for Biostatistics and Clinical Trials
Peter MacCallum Cancer Centre
Ph: 9656 3639