[R] Is this a bug of pweibull()?

[ripley@stats.ox.ac.uk]

It's a bug in R's replacement for expm1 (which I believe you wrote
Martin).  I've just spent 30mins debugging this: it's giving wrong answers
for large negative x.

On Sat, 11 May 2002, Martin Maechler wrote:

> >>>>> "Lu" == Lu Chi-Hsien Joseph <cjlu at ibm.stat.ncku.edu.tw> writes:
>
>     Lu> In rw1050, I found that
>     >> pweibull(3:10, 2)
>     Lu> [1] 0.9998766 0.9999999 1.0000000 1.0000000       NaN       NaN
>     Lu> [7]       NaN       NaN
>     Lu> Warning message:
>     Lu> NaNs produced in: pweibull(q, shape, scale, lower.tail, log.p)
>
>     Lu> more surprisingly,
>     >> pweibull(3:10, 2.1)
>     Lu> [1] 0.9999566 1.0000000 1.0000000      -Inf       NaN       NaN
>     Lu> [7]       NaN       NaN
>     Lu> Warning message:
>     Lu> NaNs produced in: pweibull(q, shape, scale, lower.tail, log.p)
>
>     Lu> Is this a bug of pweibull() in rw1050?
>
> Probably a problem with Windows / Math library behavior.
> The above example works fine in three different Unix versions I
> have access to (on Saturday morning).
>
> Can others, particularly Windows users, check this?
>
> Thanks,
> Martin Maechler
>
>     >> version
>     Lu> _
>     Lu> platform i386-pc-mingw32
>     Lu> arch     i386
>     Lu> os       mingw32
>     Lu> system   i386, mingw32
>     Lu> status
>     Lu> major    1
>     Lu> minor    5.0
>     Lu> year     2002
>     Lu> month    04
>     Lu> day      29
>     Lu> language R
>
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-- 
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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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