Hi,
This is easy if the gender and age are already vectors of some sort of the same
size.
SEXP df = PROTECT(allocVector(VECSXP, 2));
SET_VECTOR_ELT(df,0,gender) ;
SET_VECTOR_ELT(df,1,age) ;
SEXP names = PROTECT(allocVector(STRSXP,2));
SET_STRING_ELT(names,0,mkChar("age"))
SET_STRING_ELT(names,0,mkChar("gender"))
setAttrib(df, R_NamesSymbol, names );
setAttrib(df, R_ClassSymbol, mkString("data.frame"));
SEXP rn = PROTECT(allocVector(INTSXP,2));
INTEGER(rn)[0] = NA_INTEGER ;
INTEGER(rn)[1] = -length(gender);
setAttrib(df, R_RowNamesSymbol, rn) ;
UNPROTECT(3) ;
return df ;
If you really want to call back to R and make a call as you did before, you can
do something like this:
SEXP call = PROTECT(lang4(install("data.frame"), age, gender,
ScalarLogical(FALSE))) ;
SET_TAG(CDR(call), install("age")) ;
SET_TAG(CDDR(call), install("gender")) ;
SET_TAG(CDR(CDDR(call)), install("stringsAsFactors")) ;
SEXP df = PROTECT(eval(call, R_GlobalEnv)) ;
UNPROTECT(2) ;
return df ;
Or you can use Rcpp:
DataFrame df = DataFrame::create(
_["age"] = age, _["gender"] = gender, _["stringsAsFactors"] = FALSE
) ;
Romain
Le 3 avr. 2014 à 07:40, Sandip Nandi <sanna...@umail.iu.edu> a écrit :
> Hi ,
>
> I am asking too many questions , sorry for that . I am creating a data
> frame in C itself , reading a table .
>
> The data frame calling code looks like this
> ======================================
>
> *PROTECT(dfm=lang2(install("data.frame"),df));*
> *SEXP res = PROTECT(eval(dfm,R_GlobalEnv));*
>
> UNPROTECT(2);
> return res;
> ==================================
>
> It works fine , now the problem is I want to do the below one from C
> itself ( adding the *stringsAsFactors = FALSE* parameter)
>
> df <- data.frame(gender, age, *stringsAsFactors = FALSE*);
>
> How can I do it from C , adding extra parameters. Anyone has pointer or any
> example . It will be great help. I find the arguments will always be in
> pair , i don't find any example.
>
>
> I try to see the source code ,not able to make it
>
> Thanks
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