[Rd] Bug in parse(text = <long polynom>) (PR#7022)
ripley at stats.ox.ac.uk
ripley at stats.ox.ac.uk
Fri Jun 25 10:09:21 CEST 2004
On 25 Jun 2004, Peter Dalgaard wrote:
> maechler at stat.math.ethz.ch writes:
>
> > Merci beaucoup, Jean,
> > for the bug report -- which I'm no "completeing" to R-bugs
>
> But you're still requiring library(polynom) for triggering the bug. If
> we are to be sure that it is not a bug in that package
There seems to be in that it is not using the R code from `S Programming'
p.95, according to the original report.
> but a bug in R,
> you need to include the definition of at least polynomial() with the
> instructions to reproduce the effect...
>
> [snip]
> > library(polynom)
> >
> > x <- polynomial()
> > z <- (1+x)^100
> > zh <- horner(z)
Hmm, horner is not in the package! It is a function internal to
as.function.polynomial.
as.function(z) segfaults at
#0 R_TextBufferGetc (txtb=0xffda00)
at /users/ripley/R/cvs/R-devel/src/main/iosupport.c:232
#1 0x080c7623 in text_getc () at ./gram.y:1011
#2 0x080c6eed in xxgetc () at ./gram.y:291
#3 0x080c7bc5 in token () at ./gram.y:1496
#4 0x080c85c5 in Rf_yylex () at ./gram.y:1894
#5 0x080c8bef in Rf_yyparse () at /usr/share/bison/bison.simple:573
#6 0x080c997e in R_Parse1 (status=0xbfffda58) at ./gram.y:941
#7 0x080c9aad in R_Parse (n=-1, status=0xbfffda58) at ./gram.y:1076
#8 0x080c9c1e in R_ParseVector (text=0xffffffff, n=-1, status=0xffffffff)
at ./gram.y:1153
#9 0x0813c3d9 in do_parse (call=0x8500c00, op=0xffffffff, args=0x84fb898,
env=0x8ed385c) at /users/ripley/R/cvs/R-devel/src/main/source.c:68
so that's definitely a bug in R. It is being asked to parse a very long
line and a highly-nested expression. I suspect the latter is the problem.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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