[R] Error in dyn.load

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon Sep 1 23:57:07 CEST 2003

Did you follow the instructions in Writing R Extensions?

You need to make sure you include the proper header files, as length
is a C and not C++ export from R.bin, and in any case it is remapped in R.

On Mon, 1 Sep 2003, Philip Silva wrote:

> Hi,
> I've created a shared library from including this code (with g++ 
> -I/usr/local/lib/R/include -I/usr/local/include -c Rtest.cpp; g++ 
> -shared -L/usr/local/lib -o Rtest.so Rtest.cpp):
> void check_data (SEXP data) {
> 	int l=length (data);
> }
> But when I try to load it in R I get this error message:
> unable to load shared library ...
> ...
>   undefined symbol: _Z9Rf_lengthP7SEXPREC
> How can I solve this problem?

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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