[Rd] C API to get numrow of data frame

[Murray Stokely]

The simplest case would be:

   int num_rows = Rf_length(VECTOR_ELT(dataframe, 0));
   int num_columns = Rf_length(dataframe);

There may be edge cases for which this doesn't work; would need to
look into how the dim primitive is implemented to be sure.

               - Murray


On Mon, Mar 31, 2014 at 4:40 PM, Sandip Nandi <sannandi at umail.iu.edu> wrote:
> Hi ,
>
> Is there any C API to the R API  nrow of dataframe ?
>
> x<- data.frame()
> n<- nrow(x)
> print(n)
> 0
>
>
> Example :
> My C function which deals with data frame looks like and I don't to send
> the  number of rows of data frame .I want to detect it from the function
> itself, my function take data frame as argument and do some on it. I want
> API equivalent to nrow. I tried Rf_nrows,Rf_ncols . No much help.
>
> SEXP  writeRR(SEXP dataframe) {
>
> }
>
>
> Any help is very appreciated.
>
> Thanks,
> Sandip
>
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>
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