[R] R keeps crashing when executing 'rlogspline'

[Uwe Ligges]

Charles C. Berry wrote:
> On Thu, 31 May 2007, Jacques Wagnor wrote:
> 
>> Dear List,
>>
>> I have a simple model as follows:
>>
>> x <- rnorm(500)
>> library(logspline)
>> fit <- logspline(x)
>> n <- 1000000
>> y <- replicate(n, sum(rlogspline(rpois(1,10), fit))) # last line
>>
> 
> What you do not see in RGui is this:
> 
> 
>   *** caught segfault ***
> address (nil), cause 'memory not mapped'
> 
> Traceback:
>   1: .C("rpqlsd", as.double(c(fit$coef.pol, fit$coef.kts)), 
> as.double(fit$knots),     as.double(fit$bound), as.integer(0), qq = 
> as.double(p), as.integer(length(fit$knots)),     as.integer(length(p)), 
> PACKAGE = "logspline")
>   2: qlogspline(pp, fit)
> [rest deleted]
> 
> I think you are getting zero from rpois(1,10) with larger values of n.
> 
> rlogspline does not check for n==0
> 
> This results in calling qlogspline( numeric(0), fit ) and generates the 
> segfault, I guess.
> 
> So figure out what should happen when rpois(1,10) returns zero and avoid 
> calling rlogspline in those cases.


And please do not forget to notify the package maintainer that there is 
a bug in the package. The maintainer will probably be happy to know 
about it. I am CCing to Charles Kooperberg.

Uwe Ligges





> If 'zero.value' is a suitable value, then this will work:
> 
>> library(logspline)
>> x <- rnorm(500)
>> fit <- logspline(x)
>> res <- sapply(1:50, function(x) sum(rlogspline(x, fit)))
>> n <- 1000000
>> rp <- rpois(n,10)
>> y <- c( zero.value, res )[ rp+1 ] ## table lookup is faster!
> 
> Chuck
> 
> 
>> The problem I keep getting is Rcrashes when doing the last line.  It
>> seems to be fine if n is small, but not if n is 1000000.  The message
>> I keep getting is:
>>
>> "R for Windows GUI front-end has encountered a problem and needs to
>> close.  We are sorry for the inconvenience.  If you were in the middle
>> of something, the information you were working on might be lost."
>>
>> Any insights would be appreciated,
>>
>> Jacques
>>
>> platform       i386-pc-mingw32
>> arch           i386
>> os             mingw32
>> system         i386, mingw32
>> status
>> major          2
>> minor          5.0
>> year           2007
>> month          04
>> day            23
>> svn rev        41293
>> language       R
>> version.string R version 2.5.0 (2007-04-23)
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch 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.
>>
> 
> Charles C. Berry                        (858) 534-2098
>                                           Dept of Family/Preventive Medicine
> E mailto:cberry at tajo.ucsd.edu	         UC San Diego
> http://biostat.ucsd.edu/~cberry/         La Jolla, San Diego 92093-0901
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.