[Rd] include libraries for C code called from R

From: <braunm_at_MIT.EDU>
Date: Tue 12 Dec 2006 - 20:50:50 GMT

I hope that someone on this list can help me with this issue. I have searched through all of the documentation and mail archives for a solution, but have been unable to find an answer that addresses my particular problem directly.

Suppose I am writing some C code that I want to access from R through the .C function. As part of the C function, I want to include an external C library, such as the GNU gsl library. So, if I want to compute the value of a Gaussian hypergeometric function, my C code would be:

#include </usr/include/gsl/gsl_sf_hyperg.h> void gslTestHG (double *a, double *b, double *c, double *x, double *val ) {

        *val = gsl_sf_hyperg_2F1(*a,*b,*c,*x);

I then compile this file (successfully, on a Linux machine with gcc installed) using R CMD SHLIB gslTest.c. The message from the complier is:

gcc -I/usr/lib64/R/include -I/usr/lib64/R/include  -I/usr/local/include   -fpic
-O2 -g -c RgslTest.c -o RgslTest.o
gcc -shared -L/usr/local/lib64 -o RgslTest.so RgslTest.o -L/usr/lib64/R/lib -lR

When I go into R and enter the command dyn.load("gslTestHG.so"), I get the following error:

Error in dyn.load(x, as.logical(local), as.logical(now)) : unable to load shared library '/mnt/san2/braunm/winshare/braunm/Cpractice/RgslTest.so':   /mnt/san2/braunm/winshare/braunm/Cpractice/RgslTest.so: undefined symbol: gsl_sf_hyperg_2F1

So, it looks like R is not recognizing the function call within my own C function, even though the library was included.

Note that this is a simpler example of my "real" problem, the details of which would bog down discussion. I know that I could use the gsl package, or include the Rmath.h library, to perform this particular task. My primary need is the ability to call C libraries from wtihin my own C code.

But I would greatly appreciate any advice or suggestions on how to solve this problem. I am a novice C programmer and Linux user, but it seems like this should be a simple fix.

Many thanks in advance,

Michael Braun
MIT Sloan School of Management

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https://stat.ethz.ch/mailman/listinfo/r-devel Received on Wed Dec 13 13:00:04 2006

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