Re: [Rd] Generate random numbers in Fortran

Sat, 14 Feb 2009 03:10:28 -0800 

As I am wanting to generate a beta, then I created a function in C to
generate a beta, but the problem appears when I go to compile

My function in C is

#include <R.h>
#include <Rmath.h>
#include <math.h>

void F77_SUB(myrbeta)(double* px)
{ 
    GetRNGstate();
    *px = rbeta(1.00,3.00);
    PutRNGstate();
}

My function in Fortran is

subroutine blah(a)
double precision (a)
call myrbeta(RND)
end

The error

fmc...@fmcron-desktop:~/teste$ R CMD SHLIB mat.c blah.f
gcc -std=gnu99 -I/usr/share/R/include      -fpic  -g -O2 -c mat.c -o mat.o
gfortran   -fpic  -g -O2 -c blah.f -o blah.o
blah.f:1.1:

subroutine 
blah(a)                                                     
 
1
Erro: Non-numeric character in statement label at (1)
blah.f:1.1:

subroutine 
blah(a)                                                     
 
1
Erro: Unclassifiable statement at (1)
blah.f:2.1:

double precision 
(a)                                                   
 
1
Erro: Non-numeric character in statement label at (1)
blah.f:2.1:

double precision 
(a)                                                   
 
1
Erro: Unclassifiable statement at (1)
blah.f:4.1:

end                                                                    
 
1
Erro: Non-numeric character in statement label at (1)
blah.f:4.1:

end                                                                    
 
1
Erro: Unclassifiable statement at (1)
make: ** [blah.o] Erro 1


             Fábio Mathias 
Corrêa                       UFLA


--- Em sex, 13/2/09, Kjell Konis <[email protected]> escreveu:
De: Kjell Konis <[email protected]>
Assunto: Re: [Rd] Generate random numbers in Fortran
Para: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Data: Sexta-feira, 13 de Fevereiro de 2009, 16:49

Take a look at section 6.6 in Writing R Extensions. It describes how to call C
functions from FORTRAN. Basically it just boils down to this, in a C file define
the functions

void F77_SUB(fseedi)(void)
{
  int x = 100;
  seed_in(&x);
}


void F77_SUB(fseedo)(void)
{
  int x = 100;
  seed_out(&x);
}


void F77_SUB(myrunif)(double* px)
{
        *px = unif_rand();
}


Then you could write a FORTRAN subroutine like

      subroutine blah()
      implicit double precision (a-h,o-z)
      call fseedi()
      call myrunif(RND)
      call fseedo()
      end

The fseed* subroutines only need to be called once, fseedi at the beginning of
your FORTRAN code and fseedo at the end.

HTH,
Kjell


On 13 févr. 09, at 17:32, Fabio Mathias wrote:

> Hi!!!
> It would like to know if it exists a form to use the functions to
> generate variates in FORTRAN with the same easiness I use that them in
> C? Or not?
> If yes. They would have some example? I would like to use the functions
rbeta, rlnorm and others!
> 
> 
> Sorry my english..rsrsrs
> 
> Thanks!!!
> 
> 
>              Fábio Mathias Corrêa    University Federal of the Lavras -
Brazil
> 
> 
> 
>      Veja quais são os assuntos do momento no Yahoo! +Buscados
> 
>       [[alternative HTML version deleted]]
> 
> <ATT00001.txt>




      Veja quais são os assuntos do momento no Yahoo! +Buscados

        [[alternative HTML version deleted]]


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