[Rcpp-devel] Doubt about best pratices

[Roberto Spadim]

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
> >_______________________________________________
> >Rcpp-devel mailing list
> >Rcpp-devel at lists.r-forge.r-project.org
> >https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
> --
> Sent from my phone. Please excuse my brevity.
>
-- 
Roberto Spadim
SPAEmpresarial - Software ERP/Scada
Eng. Automação e Controle, Eng. Financeira
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