From: Marion Dumas <mariouka_at_gmail.com>

Date: Thu, 14 Apr 2011 21:41:28 -0400

R-help_at_r-project.org mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Fri 15 Apr 2011 - 06:12:27 GMT

Date: Thu, 14 Apr 2011 21:41:28 -0400

Hello R-help list

I'm trying to run 1 billion iterations of a code with calls to random
distributions to implement a data generating process and subsequent
computation of various estimators that are recorded for further
comparison of performance. I have two question about how to achieve
this:

1. the most important: on my laptop, R gives me an error message
saying that it cannot allocate sufficient space for the matrix that is
meant to record the results (a 1 billion by 4 matrix). Is this
computer-specific? Are there ways to circumvent this limit? Or is it
hopeless to run 1 billion iterations in one batch? ( the alternative
being to run, for example, 1000 iterations of a 1 million iteration
process that spits out output files that can then be combined manually).
2. secondly: when I profile the code on a smaller number of
iterations, it says that colSums is the function that has the longest
self time. I am using this to compute stratum-specific treatment
effects. My thinking was that the fastest way to compute mean outcome
conditional on treatment for each stratum would be to combine all
strata in one matrix and apply colSums-type functions on it. Maybe I
am wrong and there are better ways?

Thank you in advance for any help you may provide.

R-help_at_r-project.org mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Fri 15 Apr 2011 - 06:12:27 GMT

Archive maintained by Robert King, hosted by
the discipline of
statistics at the
University of Newcastle,
Australia.

Archive generated by hypermail 2.2.0, at Fri 15 Apr 2011 - 07:00:29 GMT.

*
Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help.
Please read the posting
guide before posting to the list.
*