[Rcpp-devel] Doubt about best pratices

Uhm
Converting from one to other copy data? From dataframe to matrix at least?

Em sáb., 30 de abr. de 2022 às 14:26, Jeff Newmiller <
jdnewmil at dcn.davis.ca.us> escreveu:

A data frame is designed to represent different types in different
columns. A matrix is designed so that all elements are the same.

It sounds like you need matrices for your algorithm. I would simply
require that... or attempt to convert it immediately and stop if the result
is not numeric.

On April 30, 2022 10:16:04 AM PDT, Roberto Spadim <roberto at spadim.com.br>
wrote:

Hi folks!

What's the best pratices to accept a dataframe and numericmatrix in a

function?

Should I have two different methods to deal with NumericMatrix and

DataFrame?

Could I convert DataFrame to matrix? What's the impact of doing this,
i.e. does the as.matrix copy dataframe data?

Thanks in advance!

---
Today I'm doing something like this:

void RCPP_function(const RObject &vec, const RObject &mat) {
 if(mat.isNULL())
   Rcpp::stop("mat can't be null");
 NumericMatrix variable_matrix;
 if (is<NumericMatrix>(mat))
   variable_matrix = as<NumericMatrix>(mat);
 else
   variable_matrix = Rcpp::internal::convert_using_rfunction(mat,

"as.matrix");

 NumericVector variable_vector;
 if((is<NumericVector>(target) || is<DataFrame>(target)) &&

!target.isNULL()){

     variable_vector=as<NumericVector>(target);
 }else{
     variable_vector=colMeans(variable_matrix);
 }

 ...
 do something with data
 but here it's sure to be:
  NumericVector (variable_vector)
  NumericMatrix (variable_matrix)
 ...
}


--
Roberto Spadim

--
Sent from my phone. Please excuse my brevity.