R bindings for the xtensor C++ multi-dimensional array library.

• xtensor is a C++ library for multi-dimensional arrays enabling numpy-style broadcasting and lazy computing.

• xtensor-r enables inplace use of R arrays in C++ with all the benefits from xtensor

  • C++ universal functions and broadcasting
  • STL - compliant APIs.
  • A broad coverage of numpy APIs (see the numpy to xtensor cheat sheet).

xtensor-r can be used either to author C++ extensions for R with Rcpp, or applications that embed the R interpreter with RInside.

Example

#include <numeric>                    // Standard library import for std::accumulate
#define STRICT_R_HEADERS              // Otherwise a PI macro is defined in R
#include "xtensor/xmath.hpp"          // xtensor import for the C++ universal functions
#include "xtensor-r/rarray.hpp"       // R bindings

#include <Rcpp.h>

using namespace Rcpp;

// [[Rcpp::plugins(cpp14)]]

// [[Rcpp::export]]
double sum_of_sines(xt::rarray<double>& m)
{
    auto sines = xt::sin(m);  // sines does not actually hold values.
    return std::accumulate(sines.cbegin(), sines.cend(), 0.0);
}

v <- matrix(0:14, nrow=3, ncol=5)
s <- sum_of_sines(v)
s

# prints 1.2853996391883833

Installation

Installation of the standalone C++ library

xtensor-r a header-only C++ library. It has been packaged for the mamba (or conda) package manager.

mamba install xtensor-r -c conda-forge

xtensor-r can be installed from source with cmake in any installation prefix. For example, on unix systems

cmake -D CMAKE_INSTALL_PREFIX=/prefix/path/ .
make
make install

Installation of the R package

We provide a R package for Xtensor on both conda and CRAN (Comprehensive R Archive Network). The packaging boilerplate for the R package is available at https://github.com/xtensor-stack/Xtensor.R.

To install the R package with conda:

conda install r-xtensor -c conda-forge

To install the R package from CRAN:

R CMD INSTALL xtensor

or from the GitHub repository using devtools

devtools::install_github("xtensor-stack/Xtensor.R")

The CRAN package vendors the headers for xtensor-r, xtensor,xtlandxsimd`.

Documentation

To get started with using xtensor-r, check out the full documentation

http://xtensor-r.readthedocs.io/

Dependencies on xtensor and Rcpp

xtensor-r depends on the xtensor and Rcpp libraries

• Core xtensor headers are vendored in the CRAN package.
• When using the conda, or debian package managers, xtensor-r has a dependency on xtensor.

License

We use a shared copyright model that enables all contributors to maintain the copyright on their contributions.

This software is licensed under the BSD-3-Clause license. See the LICENSE file for details.