>>>>> "BDR" == Prof Brian Ripley <[EMAIL PROTECTED]>
>>>>> on Tue, 26 Jun 2007 18:38:27 +0100 (BST) writes:
BDR> Remember that you only get S4 dispatch on Math for S4
BDR> generics. log10 is not an S4 generic until you make it
BDR> one. From the help page
BDR> Note: currently those members which are not
BDR> primitive functions must have been converted to S4
BDR> generic functions (preferably _before_ setting an S4
BDR> group generic method) as it only sets methods for known
BDR> S4 generics. This can be done by a call to
BDR> 'setGeneric', for example 'setGeneric("round",
BDR> group="Math2")'.
BDR> Had you done that (it is not mentioned)?
no. embarrassing, since I "once" new about it
(had to do that in the Matrix package)...
>> From my notes about S4 issues sent to R core a while
>> back:
BDR> 1) Setting methods on a group generic only sets methods
BDR> for existing generics, and only primitives are ab
BDR> initio generic.
BDR> ?setGeneric and ?Arith differ as to how other
BDR> members should be converted into generics (one arg or
BDR> two), and the example (setGeneric("+")) seems pointless
BDR> as that is already generic.
BDR> Whereas all of Ops (and its subgroups) and Complex
BDR> are ab initio generic, none of Summary is and log,
BDR> log10, gamma, lgamma, round, signif and trunc are not.
BDR> The discrepancies between the S3 and S4 group
BDR> generics are hard to explain: sign, digamma, trigamma
BDR> and gammaCody are S3 group generic but not S4 group
BDR> generic (and sign is S4 generic). log10 is S4 group
BDR> generic but log2 is not. This is probably all history,
BDR> but not at all obvious to end users.
BDR> so the issue has been raised before.
Indeed. Thanks a lot, Brian!
Martin
BDR> On Tue, 26 Jun 2007, Martin Maechler wrote:
>>>>>>> "MM" == Martin Maechler <[EMAIL PROTECTED]>
>>>>>>> on Sat, 23 Jun 2007 00:36:43 +0200 writes:
>>
>> {on R-help}
>>
>> [.....................] [.....................]
>>
>> >> Duncan Murdoch
>>
DM> You might have better luck with
>>
DM> log1p(tasa)
>>
MM> {very good point, thank you, Duncan!}
>>
DM> if the authors of the Matrix package have written a
DM> method for log1p(); if not, you'll probably have to do
DM> it yourself.
>>
MM> They have not yet.
>>
MM> Note however that this - and expm1() - would
MM> automagically work for sparse matrices if these two
MM> functions were part of the "Math" S4 group generic.
>>
MM> I'd say that there's only historical reason for them
MM> *not* to be part of "Math", and I am likely going to
MM> propose to change this ....
>>
>> I'm now going to propose ...
>>
>> As I found, expm1() and log1p() already *HAVE BEEN* in
>> the S3 "Math" group generic ``automagically by
>> implementation''. Just the documentation for this fact
>> has been missing.
>>
>> Hence, I've added that doc (uncommitted) and I'm about to
>> add them to the S4 Math group as well. When doing so,
>> I'd like to add few more functions to make S3 and S4
>> "Math" a bit more compatible : Consequently, I'm
>> proposing to add the following functions to the S4 Math
>> group generic :
>>
>> - log1p, expm1
>>
>> - cummax, cummin {S3 has them; cumprod(), cumsum() are
>> already}
>>
>> - digamma, trigamma {S3 has them; gamma(), lgamma() are
>> already}
>>
>> ----
>>
>> When trying to do the above, I'm pretty quickly
>> successful for cummax & cummin, most probably because
>> they are primitive functions. But I currently have
>> problems for the other four, and in exploring these
>> problems, I've found that
>>
>> log10()
>>
>> does not S4- dispatch on "Math" neither, which I think is
>> a pretty peculiar bug; I think if that was fixed, then my
>> code changes would also work to make log1p(), expm1(),
>> digamma() and trigamma() correctly part of "S4 - Math
>> Group".
>>
>>
>> Martin
>>
>> ______________________________________________
>> R-devel@r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
--
Brian D. Ripley, [EMAIL PROTECTED]
BDR> Professor of Applied Statistics,
BDR> http://www.stats.ox.ac.uk/~ripley/ University of
BDR> Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road,
BDR> +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865
BDR> 272595
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