using 2D array of SEXP for creating dataframe

Hi ,

I have put incomplete code here . The complete code works , My doubt is
, what I am doing logical/safe ? Any memory leak going to happen ? is
there any way to create dataframe ?

SEXP formDF() {

SEXP dfm ,head,df , dfint , dfStr,lsnm;
SEXP  valueVector[2];
char *ab[3] = {"aa","vv","gy"};
int sn[3] ={99,89,12};
char *listnames[2] = {"int","string"};
int i,j;

PROTECT(df = allocVector(VECSXP,2));

PROTECT(valueVector[0] = allocVector(REALSXP,3));
PROTECT(valueVector[1] = allocVector(VECSXP,3));
PROTECT(lsnm = allocVector(STRSXP,2));

SET_STRING_ELT(lsnm,0,mkChar("int"));
SET_STRING_ELT(lsnm,1,mkChar("string"));
SEXP rawvec,headr;

for ( i = 0 ; i < 3; i++ ) {
SET_STRING_ELT(valueVector[1],0,mkChar(listNames[i]));

REAL(valueVector[0])[i] = sn[i];
}

SET_VECTOR_ELT(df,1,valueVector[0]);
SET_VECTOR_ELT(df,0,valueVector[1]);
setAttrib(df,R_RowNamesSymbol,lsnm);

PROTECT(dfm=lang3(install("data.frame"),df,ScalarLogical(FALSE)));
SET_TAG(CDDR(dfm), install("stringsAsFactors")) ;
SEXP res = PROTECT(eval(dfm,R_GlobalEnv));

UNPROTECT(7);
return res;

}



On Thu, Jun 26, 2014 at 3:49 PM, Herv? Pag?s <hpages at fhcrc.org
<mailto:hpages at fhcrc.org>> wrote:

    Hi,


    On 06/26/2014 02:32 PM, Sandip Nandi wrote:

        Hi ,

        For our production package i need to create a dataframein C . So
        I wrote
        the following code

        SEXP dfm ,head,df , dfint , dfStr,lsnm;

        *SEXP  valueVector[2];*


        char *ab[3] = {"aa","vv","gy"};
        int sn[3] ={99,89,12};
        char *listnames[2] = {"int","string"};
        int i,j;

        //============================__=

        PROTECT(df = allocVector(VECSXP,2));

        *PROTECT(valueVector[0] = allocVector(REALSXP,3));*
        *PROTECT(valueVector[1] = allocVector(VECSXP,3));*



        PROTECT(lsnm = allocVector(STRSXP,2));

        SET_STRING_ELT(lsnm,0,mkChar("__int"));
        SET_STRING_ELT(lsnm,1,mkChar("__string"));
        SEXP rawvec,headr;
        unsigned char str[24]="abcdef";

        for ( i = 0 ; i < 3; i++ ) {

        *SET_STRING_ELT(valueVector[1]__,i,mkChar(ab[i]));*
        *REAL(valueVector[0])[i] = sn[i];*

        }


        It works , data frame is being created and executed properly .


    Really? You mean, you can compile this code right? Otherwise it's
    incomplete: you allocate but do nothing with 'df'. Same with 'lsnm'.
    And you don't UNPROTECT. With no further treatment, 'df' will be an
    unnamed list containing junk data, but not the data.frame you expect.
    So there are a few gaps that would need to be filled before this code
    actually works as intended.

    Maybe try and come back again with specific questions?

    Cheers,
    H.

      > Just curious , if I am doing anything wrong or is there another

    way around

        for creation of data-frame .  I am concerned about the SEXP 2D
        array .

        Thanks,
        Sandip

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