R devel - Nov 2010 - DBLEPR?

Ravi Varadhan and I have been looking at UCMINF to try to identify why it gives
occasional
(but not reproducible) errors, seemingly on Windows only. There is some
suspicion that its
use of DBLEPR for finessing the Fortran WRITE() statements may be to blame.
While I can
find DBLEPR in Venables and Ripley, it doesn't get much mention after about
2000 in the
archives, though it is in the R FAQ and Brian R. mentions they are in libR in a
2009 post.
Are the xxxPR routines now deprecated (particularly for 64 bit systems) or still
OK to
use?  If OK, can anyone point to documentation and examples?

JN

Reply redirected to the R-devel list.

On Tue, Nov 16, 2010 at 1:02 PM, Prof. John C Nash <nashjc at uottawa.ca>
wrote:
> Ravi Varadhan and I have been looking at UCMINF to try to identify why it
gives occasional
> (but not reproducible) errors, seemingly on Windows only. There is some
suspicion that its
> use of DBLEPR for finessing the Fortran WRITE() statements may be to blame.
While I can
> find DBLEPR in Venables and Ripley, it doesn't get much mention after
about 2000 in the
> archives, though it is in the R FAQ and Brian R. mentions they are in libR
in a 2009 post.
> Are the xxxPR routines now deprecated (particularly for 64 bit systems) or
still OK to
> use? ?If OK, can anyone point to documentation and examples?
Can you give more context?  What is UNCMINF?  Is it a package?  Is it a file?

There is a file R_SRC/src/appl/uncmin.c but it doesn't use DBLEPR
because it is C source code.  As stated in the comments

/* ../appl/uncmin.f
   -- translated by f2c (version of 1 June 1993 23:00:00).
   -- and hand edited by Saikat DebRoy
   */

/*--- The Dennis + Schnabel Minimizer -- used by R's  nlm() ---*/

I normally see digest once per day, but got msg from Doug Bates so responding
with context.

UCMINF is a package on CRAN that implements a variable metric minimizer. It does
quite
well on unconstrained problems. Stig Mortensen packaged the Fortran version for
R, but is
not at moment responding to emails. There's also a Matlab version. We have
it in optimx
and get some occasions where it just stops if we set trace>0. Other times we
can't get it
to fail. My guess is something like an undefined variable or a bad declaration
of a
pointer, but C and C++ are not languages I've much experience with.

JN

My reaction is leaning heavily towards "Virtuoso!" as opposed to
"Show Off!".

Thanks very much.

JN


On 11/16/2010 05:39 PM, Douglas Bates wrote:
> Try this.
> 
> On Tue, Nov 16, 2010 at 4:06 PM, Prof. John C Nash <nashjc at
uottawa.ca> wrote:
>> We've tried to contact Stig since July. Possibly he changed emails.
>>
>> My thought was to use Rprintf as suggested and was looking into doing
that to see if our
>> optimx problems would go away. Will keep it as open issue while we give
a bit more time
>> for response, and welcome input from others.
>>
>> JN
>>
>>
>> On 11/16/2010 04:52 PM, Douglas Bates wrote:
>>> On Tue, Nov 16, 2010 at 2:35 PM, Prof. John C Nash <nashjc at
uottawa.ca> wrote:
>>>> I normally see digest once per day, but got msg from Doug Bates
so responding with context.
>>>
>>>> UCMINF is a package on CRAN that implements a variable metric
minimizer.
>>>
>>> A pedant might point out that the package is called
"ucminf".
>>>
>>>> It does quite
>>>> well on unconstrained problems. Stig Mortensen packaged the
Fortran version for R, but is
>>>> not at moment responding to emails. There's also a Matlab
version. We have it in optimx
>>>> and get some occasions where it just stops if we set
trace>0. Other times we can't get it
>>>> to fail. My guess is something like an undefined variable or a
bad declaration of a
>>>> pointer, but C and C++ are not languages I've much
experience with.
>>>
>>> Well, it doesn't work well for me because my version of
gfortran (GNU
>>> Fortran (Ubuntu/Linaro 4.4.4-14ubuntu5) 4.4.5) objects to the
format
>>> strings in some of the Fortran WRITE statements.
>>>
>>> The recommended approach is to avoid all Fortran I/O including
writing
>>> to a Fortran character array.   As there are only 3 such WRITE
>>> statements in the Fortran code it would be very simple to replace
them
>>> with calls to C functions that in turn call Rprintf.  However, it
>>> would be best if Stig could take ownership of the modifications.
>>

G'day John,

On Tue, 16 Nov 2010 14:02:57 -0500
"Prof. John C Nash" <nashjc at uottawa.ca> wrote:
> Are the xxxPR routines now deprecated (particularly for 64 bit
> systems) or still OK to use?  
They are still OK to use, and I use them occasionally. 
> If OK, can anyone point to documentation and examples?
Section 6.5.1 "Printing from Fortran" in the "Writing R
Extensions"
manual has documentation (but no examples).  Luckily, Section 5.7
"Fortran I/O", the section that I always look at first, has a link to
Section 6.5.1. :)

Cheers,

	Berwin

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