Hello List, I have create a small package with C code. In the C code, I call Fortran routines of Lapack. Here is the call in the C function: F77_CALL(dgesvd)(&jobu, &jobvt,&size, &size,A, &size, D,U,&size,V,&size,&work1, &lwork,&error); In the src directory, I have a Makevars File with: PKG_LIBS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS) And in the beginning of C code, I include the following lines #include <stddef.h> #include <math.h> #include <time.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <assert.h> #include <Rmath.h> #include <R.h> #include <R_ext/Utils.h> #include "adesub.h" I have compiled the Package on my PC under windows XP (Rcmd install works fine). I have try to install it on another computer with R-1.9.1 running under MAC OS X (Panther 10.3.4), but the installation failed with the following message: FORWARD.C:328: error: `dgesvd_' undeclared (first use this function) FORWARD.C:328: error: (Each undeclared identifier is reported only once for each function it appears in.) make: *** [FORWARD.o] Error 1 ERROR: compilation failed for package 'Packfor2' ** Removing '/Library/Frameworks/R.framework/Versions/1.9.1/Resources/library/Packfor2' I have no idea why this installation does not work. Any advice would be very appreciate. Thanks in advance, Sincerely. St??phane DRAY -------------------------------------------------------------------------------------------------- D??partement des Sciences Biologiques Universit?? de Montr??al, C.P. 6128, succursale centre-ville Montr??al, Qu??bec H3C 3J7, Canada Tel : (514) 343-6111 poste 1233 Fax : (514) 343-2293 E-mail : stephane.dray at umontreal.ca -------------------------------------------------------------------------------------------------- Web http://www.steph280.freesurf.fr/