>>> strongly disagree. I'm appalled to see that sentence here.
>> >
>> > Come on!
>> >
>>> >> The overhead is significant for any large vector and it is in
>>> >> particular unnecessary since in .C you have to allocate*and copy* space
>>> >> even for results (twice!). Also it is very error-prone, because you have
>>> >> no information about the length of vectors so it's easy to run out of
>>> >> bounds and there is no way to check. IMHO .C should not be used for any
>>> >> code written in this century (the only exception may be if you are
>>> >> passing no data, e.g. if all you do is to pass a flag and expect no
>>> >> result, you can get away with it even if it is more dangerous). It is a
>>> >> legacy interface that dates way back and is essentially just re-named
>>> >> .Fortran interface. Again, I would strongly recommend the use of .Call
>>> >> in any recent code because it is safer and more efficient (if you don't
>>> >> care about either attribute, well, feel free ;)).
>> >
>> > So aleph will not support the .C interface? ;-)
>> >
> It will look at the timestamp of the source file and delete the package if it
> is not before 1980 ;). Otherwise it will send a request for punch cards with
> ".C is deprecated, please upgrade to .Call" stamped out :P At that point I'll
> be flaming about using the native Aleph interface and not the R compatibility
> layer ;)
>
> Cheers,
> S
I'll dissent -- I don't think .C is inherently any more dangerous than
.Call and prefer it's simplicity in many cases. Calling C at all is
what is inherently dangerous -- I can reference beyond the end of a
vector, write over objects that should be read only, and branch to
random places using either interface. If you are dealing with large
objects and worry about memory efficiency then .Call puts more tools at
your disposal and is worth the effort. However, I did not find the
.Call interface at all easy to use at first and we should keep that in
mind before getting too pompous in our lectures to the "sinners of .C".
(Mostly because the things I needed to know are scattered about in
multiple places.)
I might have to ask for an exemption on that timestamp -- the first bits
of the survival package only reach back to 1986. And I've had to change
source code systems multiple times which plays hob with the file times,
though I did try to preserve the changelog history to forstall some
future litigious soul who claims they wrote it first (sccs -> rcs ->
cvs -> svn -> mercurial). :-)
Terry T
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