RcppNumericVectorExample: Rcpp NumericVector example

In RcppExamples: Examples using 'Rcpp' to Interface R and C++

Description

Example on how to use a NumericVector and manipulate it with the STL.

Details

    NumericVector orig ;                 // from R
    NumericVector vec(orig.size());	 // create a target vector of the same size
    
    // we could query size via
    //   int n = vec.size();
    // and loop over the vector, but using the STL is so much nicer
    // so we use a STL transform() algorithm on each element
    std::transform(orig.begin(), orig.end(), vec.begin(), sqrt_double );

    return List::create(Named("result") = vec, 
                        Named("original") = orig);
  

As shown in the example section, provided the seed is reset, the exact same draws can be obtained in R itself – which is important for reproducibility.

Author(s)

Dirk Eddelbuettel and Romain Francois

Examples

    RcppNumericVectorExample(seq(1,9)^2)

Example output

$result
[1] 1 2 3 4 5 6 7 8 9

$original
[1]  1  4  9 16 25 36 49 64 81

RcppExamples documentation built on Aug. 25, 2019, 1:03 a.m.