R.h and Rmath.h in native C program

Question

\"R.h\" and \"Rmath.h\" are header files for an interface between R.app and C. But, they seems to be readable only through a R command \'R CMD SHLIB something.c\'

I

Answer 1

Please see the 'Writing R Extensions' manual about details, you can easily compile and link against Rmath.h and the standalone R Math library -- but not R.h. (Which you can use via Rcpp / RInside but that is a different story.)

There are a number of examples floating around for use of libRmath, one is in the manual itself. Here is one I ship in the Debian package r-mathlib containing this standalone math library:

/* copyright header omitted here for brevity */

#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;

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;
}

and on Linux you simply build like this (as I place the library and header in standard locations in the package; add -I and -L as needed on OS X)

/tmp $ cp -vax /usr/share/doc/r-mathlib/examples/test.c mathlibtest.c
`/usr/share/doc/r-mathlib/examples/test.c' -> `mathlibtest.c'
/tmp $ gcc -o mathlibtest mathlibtest.c -lRmath -lm
/tmp $ ./mathlibtest
*** loaded '/tmp/mathlibtest'
one normal 1.119638
normal via BM -1.734578
/tmp $