[R] Using LAPACK in C-code to be loaded in R - getting-started-help

[Søren Højsgaard]

I want to speed up computations (involving matrices) by writing some C-code to be loaded. In the C-code, I need to invert matrices etc. As I've understood the "writing R extensions" doc, I can use use #include <R_ext/Linpack.h> in my .c-file and get access to linpack's facilities within my C-code. 
 
Is that correct?
 
If so, can anyone point me to examples on how this is actually done in practice?
 
Best regards
Søren