[R] ALLOCATE in a FORTRAN subroutine
bhh at xs4all.nl
Fri Mar 4 09:23:01 CET 2016
> On 4 Mar 2016, at 08:51, MAURICE Jean - externe <jean-externe.maurice at edf.fr> wrote:
> Hi Berend,
>> The question belongs on the R-devel mailinglist.
> I try to find this mailing-list ...
>> You are calling your Fortran routines directly from an R file with .Fortran, I presume?
> Yes. Is there another solution (possibility ?)
Yes. Use C to interface with Fortran.
See for example packages: minpack.lm, QZ, expm, nleqslv. And more: rootSolve, ucminf.
There are probably even more.
>> Declare them with (:,:) or (*,*), allocate and the return the array? A Fortran95 pointer?
> That was what I wanted to do ...
>> I think all of that is just a no no.
> It would be a big problem with memory management but R could copy the result before the memory attached to the FORTRAN subroutine is cleared at the end of the routine. R does so strange things (for an old programmer as I am).
>> Is it possible to calculate the required size of the array in a separate routine given some parameters (as can often be done with >Lapack routines) before calling the main subroutine?
>> If so, call the sizing routine and then declare the correctly sized array in your R code and pass it to the main subroutine.
> It's a good idea : a 'two shots' routine. I'll dig that (I'll work in this direction).
Commercial: Have a look at (my) packages nleqslv and geigen for that approach.
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