# seq --> Dealing with bugs in R, etc.

**Prof Brian Ripley
**
Prof Brian Ripley <ripley@stats.ox.ac.uk>

*Tue, 15 Sep 1998 17:53:28 +0100 (BST)*

>* Date: Tue, 15 Sep 1998 09:44:15 +0200
*>* From: Martin Maechler <maechler@stat.math.ethz.ch>
*>* To: jlindsey@alpha.luc.ac.be
*>* CC: R-devel@stat.math.ethz.ch
*>* Subject: Re: seq --> Dealing with bugs in R, etc.
*>*
*>* >>>>> "Jim" == Jim Lindsey <jlindsey@alpha.luc.ac.be> writes
*>*
*>* in a private mail to me
*>*
*>* Jim> That bug in seq() really has shaken my faith in R. How
*>* Jim> many other known bugs are there that we on r-help are not informed
*>* Jim> of and which can falsify our statistical analyses??? It is
*>* Jim> imperative that patches for such things be made immediately
*>* Jim> available on r-help. Jim
*
How does that `falsify a statistical analysis'? It just gives a vector
that is slightly too long. I cannot imagine this is the worst bug
in R right now.
>* I think the answer to this should be known/discussed more widely:
*>*
*>* Jim, you are right:
*>* The patch to seq(.) should have made it to R-help.
*>* [[actually in the mean time, the issue was raised that my patch
*>* was much more than was needed for dealing with rounding errors
*>* in the seq(.,., by= ) case
*>* ]].
*>*
*>* Note that there *are* other known bugs, all(?) of which being
*>* of much more low-level (and ``deeper'') nature.
*
Not all: e.g. mahalanobis() gives incorrect results almost all the
time in 0.62.3, and glm with offset is wrong often too (and both
those are in the R-bugs database).
And seq gave wrong answers in the previous releases too:
seq(1.575, 5.125, by=0.05) was wrong. At least the simpler uses are
now correct.
I do think R-bugs is the right place for bugs.
--
Brian D. Ripley, ripley@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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