[Rd] segmentation fault in integrate (PR#812)
Torsten Hothorn
Torsten.Hothorn@rzmail.uni-erlangen.de
Fri, 12 Jan 2001 08:25:11 +0100 (MET)
> I tried to integrate numerically a function wich is similar to the
> following:
>
> > dummy <- function(x) { exp(-1*x) * dnorm(x) }
> > dummy(-100)
> [1] 0
> > dummy(-1000)
> [1] NaN
> > dummy(-10000)
> [1] NaN
>
> If I choose the lower boundary to be too small integrate causes a
> segmentation fault:
>
> > library(integrate)
> > integrate(dummy, -100, 0)$value
> [1] 1.387143
> > integrate(dummy, -1000, 0)$value
> [1] NaN
> Warning message:
> Ifail=1, maxpts was too small. Check the returned relerr! in: adapt(1,
> lower, upper, minpts, maxpts, functn, eps, ...)
> > integrate(dummy, -10000, 0)$value
> Segmentation fault
Running Version 1.2.0 Patched (2001-01-07) and integrate Version 2.2-3
on SuSE 6.4 gives:
> integrate(dummy, -1000000, 0)$value
[1] NaN
Warning message:
Ifail=1, maxpts was too small. Check the returned relerr! in: adapt(1,
lower, upper, minpts, maxpts, functn, eps, ...)
I has not able to reproduce the segfault ;-)
BTW: if one uses
> dummy <- function(x) { a <- exp(-1*x) * dnorm(x); ifelse(is.na(a), 0,
a) }
this returns
> integrate(dummy, -100, 0)$value
[1] 1.387143
> integrate(dummy, -1000, 0, maxpts=1000)$value
[1] 0.6935715
Torsten
>
> I'm running R.1.2.0 on Debian Linux.
>
> Regards
> Achim
>
>
> > version
> _
> platform i686-pc-linux-gnu
> arch i686
> os linux-gnu
> system i686, linux-gnu
> status
> major 1
> minor 2.0
> year 2000
> month 12
> day 15
> language R
>
>
>
> -------------------------
>
> Achim Zeileis
> Institut für Statistik
> Technische Universität Wien
>
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