Update
I had the chance to test the issue tonight using R version 2.12.2
on a Linux (Ubuntu 10.04.2, x86_64, kernel 2.6.32-32-generic) system:
It does also crash (with a support of 0.01 instead of 0.05 posted
earlier) running
eclat(Adult, parameter=list(support=0.01, tidLists=TRUE))
but I got some more information, which supports my initial guess:
*** caught segfault ***
address 0xa481b70, cause 'memory not mapped'
Traceback:
1: .Call("reclat", items@p, items@i, items@Dim, parameter,
control, data@itemInfo, PACKAGE = "arules")
2: eclat(Adult, parameter = list(support = 0.01,
tidLists = TRUE))
It also crashes on a virtual x86_32 Windows XP Home SP3 running on the
same linux machine ...
Does anyone know how to fix the problem and how?
Thanks and regards,
Dirk
> Hello,
>
> I'm using the eclat function of the arules package (1.0-6) for the
> identification of frequent itemsets. I need the tidLists, but if I set
> in the function tidLists=TRUE R crashes (Windows XP Professional SP3,
> 32 bit, R version 2.12.1 (2010-12-16), reproducible on two different
> computers) with two different error messages or non at all. Minimum
> examples are:
>
> library(arules)
> data("Adult")
>
> eclat(Adult, parameter=list(support=0.05, tidLists=FALSE)) # OK
> eclat(Adult, parameter=list(support=0.50, tidLists=TRUE)) # OK
> eclat(Adult, parameter=list(support=0.05, tidLists=TRUE)) # crashes
>
> I started to search the cause of the problem and figured out that the
> problem must be located in the external function reclat called in
> eclat.R using the source of the arules package:
>
> result <- .Call("reclat",
> ## transactions
> items@p,
> items@i,
> items@Dim,
> ## parameter
> parameter, control,
> data@itemInfo,
> PACKAGE = "arules")
>
> Then I looked into the source code of reclat.c, trying to follow the
> tidList=TRUE parameter, but I have no C programming experience. It
> looks to me that the problem may be in the item set report function
> "_report_R" where memory is allocated and or released (see code
> fragments below).
>
> My question are:
>
> a) Does anyone else can confirm the problem?
>
> b) Does anyone know, if this may be a problem of the binary package
> (e.g. how it was compiled) or if it is a problem of the source code
> for reclat?
>
> c) Does anyone know how to fix the problem and how?
>
> Thanks and regards,
>
> Dirk
>
>
> /*----------------------------------------------------------------------
> Item Set Report Function
> ----------------------------------------------------------------------*/
>
> static void _report_R (int *ids, int cnt, int supp, int *tal, void *data)
> {
> (...)
>
> if (flags & OF_LIST) {
> vec1 = (int*)realloc(ruleset->trnb, size1
> *sizeof(int));
> if (!vec1) {
> if (vec) free(vec);
> if (vec2) free(vec2);
> _cleanup(); error(msg(E_NOMEM));}
> ruleset->trnb = vec1;
> }
> (...)
> if (flags & OF_LIST) { /* if to list the transactions, */
> h = ruleset->trtotal;
> if (supp < 0) { /* if bit vector representation */
> for (i = 0; i < tacnt; i++) { /* traverse the bit vector */
> if (h >= size2) {
> size2 += (size2 > BLKSIZE) ? (size2 >> 1) :
> BLKSIZE;
> vec1 = (int*)realloc(ruleset->trans, size2
> *sizeof(int));
> if (!vec1) {
> if (vec) free(vec);
> if (vec2) free(vec2);
> _cleanup(); error(msg(E_NOMEM));}
> ruleset->trans = vec1;
> }
> if (tal[i >> BM_SHIFT] & (1 << (i & BM_MASK))) {
> /*Rprintf(" %d", i+1);*/
> ruleset->trans[h] = i;
> h++;
> }
> }
> } /* print the indices of set bits */
> else { /* if list of transaction ids */
> if ((h + supp) >= size2) {
> while ((h + supp) >= size2) {
> size2 += (size2 > BLKSIZE) ? (size2 >> 1) :
> BLKSIZE;
> }
> vec1 = (int*)realloc(ruleset->trans, size2
> *sizeof(int));
> if (!vec1) {
> if (vec) free(vec);
> if (vec2) free(vec2);
> _cleanup(); error(msg(E_NOMEM));}
> ruleset->trans = vec1;
> }
> for (i = 0; i < supp; i++) {
> /*Rprintf(" %d", tal[i]); */
> ruleset->trans[h] = tal[i];
> h++;
> } /* traverse and print */
> }
> ruleset->trtotal = ruleset->trnb[ruleset->rnb] = h;
> } /* the transaction identifiers */
> (...)
______________________________________________
R-help@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.
