Hi, I'm quite knew in R, so I might not have the R specific jargon. But here is my problem, I'm trying to access and use variabels given by a function environment, more specifically the rho in do_optim in src/main/optim.c
According to the documentation http://cran.r-project.org/doc/manuals/R-ints.html#The-_0027data_0027 the envsxp is defined as a tagged pairlist. "ENVSXP: Pointers to the frame, enclosing environment and hash table (NULL or a VECSXP). A frame is a tagged pairlist with tag the symbol and CAR the bound value." But I'm having troubles accessing the data. I've written a small function called printNames that looks like ----------------------- void printNames(SEXP list){ SEXP names = getAttrib(list, R_NamesSymbol); int i; Rprintf("List is of length:%d\n",length(list)); for (i = 0; i < length(list); i++) Rprintf("name of id:%d\t%s\n",i,CHAR(STRING_ELT(names, i))); } ----------------------- This is basicly just a copy of ----------------------- static SEXP getListElement(SEXP list, char *str) { SEXP elmt = R_NilValue, names = getAttrib(list, R_NamesSymbol); int i; for (i = 0; i < length(list); i++) if (strcmp(CHAR(STRING_ELT(names, i)), str) == 0) { elmt = VECTOR_ELT(list, i); break; } return elmt; } ----------------------- But this crashes and looks like ----------------------- List is of length:16 name of id:0 Xd� name of id:1 Xd� name of id:2 *** caught segfault *** address 0x28, cause 'memory not mapped' ------------------------ I've just added printNames(rho) in the very first line of do_optim(). Futhermore I've checked that the typeof(rho) corresponds to the #define ENVSXP 4 in Rinternals.h at line 84 Can anyone clarify how to access these enviroment variables. I believe my problem lies in the sentence "A frame is a tagged pairlist with tag the symbol and CAR the bound value." Or more precisely, I don't quite understand the struct for env exp -------------------------- struct envsxp_struct { struct SEXPREC *frame; struct SEXPREC *enclos; struct SEXPREC *hashtab; }; -------------------------- thanks in advance. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
