[R] R API - optim

[Dirk Eddelbuettel]

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.