[Rd] Problem with R math library. [and a minor bug report]

[Guillaume Yziquel]

Dirk Eddelbuettel a écrit :
> 
> Well, Debian comes to the rescue. Do 'sudo apt-get install r-mathlib' to the
> standalone library. Then copy the example file out, add the missing 'extern
> N01type N01_kind;' (and that it is missing may well be a bug -- I used 2.10.1
> here -- anyone from R Core listening in who can add the one line ?) 
> 
>    edd at ron:~> cp  /usr/share/doc/r-mathlib/examples/test.c /tmp/
>    edd at ron:~> grep extern /tmp/test.c
>    extern N01type N01_kind; /* from nmath/snorm.c */
>    edd at ron:~> gcc  -o /tmp/mathlibtest  /tmp/test.c -lRmath -lm
>    edd at ron:~> /tmp/mathlibtest 
>    *** loaded '/tmp/mathlibtest'
>    one normal 1.119638
>    normal via BM -1.734578
>    edd at ron:~> 

OK. Thanks. Hadn't noticed the documentation of r-mathlib. Should have 
known better.

However, I still do not understand what the -lm is useful for.

> I hope this answers your questions -- the standalone math library links with
> only its libRmath and nothing else from R. It also only consume Rmath.h
> (which I put into /usr/include so you need no -I arguments to gcc).

Yes, that answers my question.

> Hope this helps,  Dirk
> 
> PS For reference, here is test.c with line edited in:
> 
> /*
>  *  Mathlib : A C Library of Special Functions
>  *  Copyright (C) 2000-7  The R Development Core Team
>  *
>  *  This program is free software; you can redistribute it and/or modify
>  *  it under the terms of the GNU General Public License as published by
>  *  the Free Software Foundation; either version 2 of the License, or
>  *  (at your option) any later version.
>  *
>  *  This program is distributed in the hope that it will be useful,
>  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>  *  GNU General Public License for more details.
>  *
>  *  You should have received a copy of the GNU General Public License
>  *  along with this program; if not, a copy is available at
>  *  http://www.r-project.org/Licenses/
>  *
>  */
> 
> #define MATHLIB_STANDALONE 1
> #include <Rmath.h>
> 
> #include <stdio.h>
> typedef enum {
>     BUGGY_KINDERMAN_RAMAGE,
>     AHRENS_DIETER,
>     BOX_MULLER,
>     USER_NORM,
>     INVERSION,
>     KINDERMAN_RAMAGE
> } N01type;
> 
> extern N01type N01_kind; /* from nmath/snorm.c */
>  
> int
> main(int argc, char** argv)
> {
> /* something to force the library to be included */
>     qnorm(0.7, 0.0, 1.0, 0, 0);
>     printf("*** loaded '%s'\n", argv[0]);
>     set_seed(123, 456);
>     N01_kind = AHRENS_DIETER;
>     printf("one normal %f\n", norm_rand());
>     set_seed(123, 456);
>     N01_kind = BOX_MULLER;
>     printf("normal via BM %f\n", norm_rand());
>     
>     return 0;
> }
> 
> 


-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/