From edd at debian.org  Sun Jul 14 21:03:22 2013
From: edd at debian.org (Dirk Eddelbuettel)
Date: Sun, 14 Jul 2013 14:03:22 -0500
Subject: [Rd] unmapped memory core dump with pure R program?
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On 14 July 2013 at 11:45, ivo welch wrote:
| hi dirk---look, it's a fickle bus segfault. ?if you read my email in full, you
| will note that even eliminating an irrelevant print(head()) statement makes it
| go away. ?we are lucky it is reproducible and thus easy to track down for
| whoever wrote the code, given my code AND the data, of course. ?(maybe it
| could do with me trying to create data that are random, maybe not. ?but there
| is no point to me doing so. ?if we have the bug reproducible, we should chase
| it down when we know it appears.) ?I know that you cannot reproduce it from
| what I have posted. ?I also wrote that I will bring the tarball (with the
| files) into my office tomorrow to see if I can make it remotely available to
| simon or you, if you are interested.
| 
| I am trying to help...it did take me a day to reduce the code to figure out
| what went wrong,, and an hour to get it to this point where it is easily
| understandable, reproducible, and digestable by you.

Well your comment notwithstanding I actually had read your code snippet and
concluded that at least your initial report was wrong (as you blamed rbind,
not head which the comment now blames) but I have never made any promises to
debug this -- R memory internals requires sturdier souls than mine.

Rather, I was trying to explain to you that if you want your "so far non-bug
as not reproducible" report to have any effect, you have to give those whose
time you expect to be devoted to this at least the commonly required inputs
to be able to replicate the issue.  And no, the offer to supply 60gb of data
does not commonly count as a suitable offer.  A reproducible script might.

Dirk

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com



[Rd] unmapped memory core dump with pure R program?
Dirk Eddelbuettel