Hi everyone, we are working on highly memory consuming programs (with as few loops as possible ) and we were told that programming our loop in C would make our program "lighter". I read very carefully the documentation on R extensions and succeeded in integrating fully "C" program in R, or program using Rprintf. But we would like to integrate an R function in our dll, for instance foo, with 5 arguments, in that C program and despite all our efforts, I did no succed: we are not "programmers" at all, and the documentation regarding that point is far too complicated for me. Could anyone please give us a very simple example of integration of an R function in such a C program, further reintegrated in R? Thanks a lot by advance, Xavière Panhard University Hospital Bichat Paris, France [[alternative HTML version deleted]]