[R] Segmentation fault using integrate()

[Ben Bolker]

  I'm not sure what's going on, but I have had a similar problem, and a
workaround.  The following code will fairly reliably crash R:

library(integrate)

besfun <- function(v,minx=1e-99) {
  if (all(v==0))
     besfun(minx,minx)
  else
      besselK(sqrt(sum(v^2)),0)
}

sqval <- function(lim) {
 print(lim)
 4/(2*pi)*adapt(ndim=2,lower=c(0,0),upper=c(lim,lim),minpts=200,maxpts=NULL,functn=besfun,eps=1e-4)$value
#gc()
}

xvec <- seq(0,10,length=101)
sqvec <- sapply(xvec,sqval)

## crashes R
sqvec <- sapply(xvec,sqval)

  I think the problem may have to do with cleanup on return from an error:
if I exclude 0 from xvec above, so that I don't get the following warning
messages

   Warning message:
   Ifail=2, lenwrk was too small. -- fix adapt() !
   Check the returned relerr! in: adapt(ndim = 2, lower = c(0, 0), upper

then I don't get the crashes.

  The workaround is to call gc() every time after you call integrate() ...
you can see if it works for you.

  Ben Bolker

On Tue, 18 Jan 2000, Hubert Wong wrote:

> Hi all,
> 
> Running R 0.90.1 on a RH 6.1 system.  Installation of the
> integrate_2.1-2 package went smoothly.  My code contains a loop 
> in which integrate() is called several times in each pass.  
> I get a segmentation fault after what seems to be a random number 
> of calls to integrate().  Debug output shows:
> 
>   Program received signal SIGSEGV, Segmentation fault.
>   promiseArgs (el=0x40276414, rho=0x402977a4) at eval.c:1018
>   1018	eval.c: No such file or directory.
> 
> Does anyone have any idea what's going on?  Thanks.
> 
> Hubert
> 
> ======================================================================
> Hubert Wong                    Department of Statistics
> E-mail: hubert at stat.ubc.ca     University of British Columbia
> ======================================================================
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-- 
Ben Bolker                                  bolker at zoo.ufl.edu
Zoology Department, University of Florida   http://www.zoo.ufl.edu/bolker
318 Carr Hall/Box 118525                    tel: (352) 392-5697
Gainesville, FL 32611-8525                  fax: (352) 392-3704

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