[R] unexpected R crash - again

[Peter Dalgaard BSA]

"Andy Jaworski" <apjaworski at mmm.com> writes:

> Sorry, but I lost this thread, so I sending this as a new message.
> 
> This is really a follow-up to a post from a couple days ago saying that
> fisher.test from the ctest library crashed on the following data set:
> > T
>       [,1] [,2]
>  [1,]    2    1
>  [2,]    2    1
>  [3,]    4    0
>  [4,]    8    0
>  [5,]    6    0
>  [6,]    0    0
>  [7,]    1    0
>  [8,]    1    1
>  [9,]    7    1
> [10,]    8    2
> [11,]    1    0
> [12,]    3    1
> [13,]    1    1
> [14,]    3    0
> [15,]    7    2
> [16,]    4    1
> [17,]    2    0
> [18,]    2    0
> [19,]    2    0
...
> (2) On my Linux box I can only go to about --vsize=120M --nsize=1000k.  This
> is a Pentium MMX 266Mhz with 64Mb of memory.  The machine crashes
>      after "thinking" for about 3 seconds.  It produces segmentation
> violation error and dumps core.
> 
> It seems to me that, unless I have some unlucky machines, the problem is not
> just handling too small memory allocation ungracefully.
> 
> Any comments will be appreciated,

Aha. So it also happens on Linux. That should make debugging it quite
a bit easier. Happens here as well, and the immediate cause is that

Program received signal SIGSEGV, Segmentation fault.
0x40f9e9f0 in f2xact (nrow=0x40f9afd0, ncol=0x40f9afc8, table=0x40f9adf8, 
    ldtabl=0x40f9ae90, expect=0x40f9ae88, percnt=0x40f9ae80, emin=0x40f9ae78, 
    prt=0x40f9ae70, pre=0x40f9ae68, fact=0x40fa5008, ico=0x40fa5264, 
    iro=0x40fa52b0, kyy=0x40fa52fc, idif=0x40fa5348, irn=0x40fa5350, 
    key=0x40fa6f40, ldkey=0x40fa46a4, ipoin=0x40fa82b0, stp=0x40fa9618, 
    ldstp=0x40fa46b0, ifrq=0x40ff2460, dlp=0x4105f9b8, dsp=0x41062098, 
    tm=0x41064778, key2=0x41066e60, iwk=0x40fa5358, rwk=0x40fa6218)
    at ../../../../../R/src/library/ctest/src/fexact.c:690
690         pastp = stp[ipn + ikstp];
(gdb) p ipn
$1 = -97902590

which in turn comes from 

689         ipn = ipoin[ipo + ikkey];

with ipo & ikkey both at 622,  seemingly sane.

-- 
   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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