R help - Oct 2007 - R API - optim

I am trying to use the R API to call optim functions (nmmin, vmmin, lbfgsb,
etc.) through a C program but I couldn't find the shared library to link
under the R-2.6.0 build which is compiled under Linux (REL5).

main.cpp:35: undefined reference to `Rf_initEmbeddedR(int, char**)'
main.cpp:41: undefined reference to `nmmin'

Thanks in advance for any help.

------------------------
#include <R_ext/Applic.h>
#include <R.h>
#include <stdio.h>

double parabola(int n, double *par, void *ex) {   double xm = par[0] - 1;
  return xm * xm + 13;
}

/*
 * Copied from tests/Embedded/embeddedRCall.c:
 */


extern int Rf_initEmbeddedR(int argc, char *argv[]);
int main()
{
  char *argv[]= {"nmminDemo", "--gui=none",
"--silent"};   const int argc 3;

  double initial[1] = {1.5};
  double result[1];
  double value;
  int convergenceCode;

  /*
   * The following values are based on the help
   * page for optim.
   */


  const double abstol = 1e-16;
  const double reltol = 1e-8;
  const double alpha = 1.0; /* reflection factor */   const double beta 0.5; /*
contraction factor */   const double gamm = 2.0; /* expansion factor
*/   const int trace = 0; /* tracing on */
  int fncount;
  const int maxit = 10000;
  Rf_initEmbeddedR(argc, argv);

  nmmin(1, initial, result, &value, parabola,

        &convergenceCode, abstol, reltol,
        NULL, alpha, beta, gamm,
        trace, &fncount, maxit);
  printf("fncount: %d\n", fncount);

  printf("convergence code: %d\n", convergenceCode);  
printf("min of %f at
x = %f\n", value, result[0]);   return 0;
}

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On 14 October 2007 at 05:58, Wang Chengbin wrote:
| I am trying to use the R API to call optim functions (nmmin, vmmin, lbfgsb,
| etc.) through a C program but I couldn't find the shared library to link
| under the R-2.6.0 build which is compiled under Linux (REL5).

You can't just call an _R_ function from a _C_ program as you do below.

| extern int Rf_initEmbeddedR(int argc, char *argv[]);
| int main()
| {
|   char *argv[]= {"nmminDemo", "--gui=none",
"--silent"};   const int argc | 3;
| 
|   double initial[1] = {1.5};
|   double result[1];
|   double value;
|   int convergenceCode;
| 
|   /*
|    * The following values are based on the help
|    * page for optim.
|    */
| 
| 
|   const double abstol = 1e-16;
|   const double reltol = 1e-8;
|   const double alpha = 1.0; /* reflection factor */   const double beta | 0.5;
/* contraction factor */   const double gamm = 2.0; /* expansion factor
| */   const int trace = 0; /* tracing on */
|   int fncount;
|   const int maxit = 10000;
|   Rf_initEmbeddedR(argc, argv);
| 
|   nmmin(1, initial, result, &value, parabola,

Not a function at the C level.

You need to rethink what you want to do, and how you go about it. Go back to
the R Extensions manual, or look for example at Rserve by Simon which allows
you to 'think in terms of R functions' but access them via a network
layer
(which can be, which doesn't have to be, on the same machine).

Hope this helps,  Dirk

-- 
Three out of two people have difficulties with fractions.