hi dirk---it is not 100% clear what causes it.  it is a segfault.  the bug
does not show up at the head command.  it shows up at a different place,
but removing an unrelated print(head()) command means the bug does not
appear later.

it weighs in at about 280MB.  I will make it available to simon on Monday,
after verifying first that I can replicate it on another computer in my
office.

look, dirk, I know you put in an enormous amount of effort toward making R
more useful.  I know you are trying to help and helping.  however, some of
the R experts incl yourself can be sometimes aggressive to the point where
it deters other R users from trying to provide help and feedback.  even the
comments of beginners can be useful in pointing out how to make R a better
experience.  sometimes, novices like me stumble over stuff that can
help...and sometime we cry wolf when there is none because we misunderstand
things or did not remember everything in the docs (or did not "read the
code").  I believe some other R experts are struggling with the tone in the
R list(s), too.  in this sense, the R community is an odd beast.  on the
one hand, very gracious and helpful.  on the other hand, sometimes
seemingly almost bitter.

regards,

/iaw

----
Ivo Welch (ivo.welch@gmail.com)


On Sun, Jul 14, 2013 at 12:03 PM, Dirk Eddelbuettel <edd@debian.org> wrote:

>
> 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@debian.org | http://dirk.eddelbuettel.com
>

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