paper.md
In ggrothendieck/ryacas: R Interface to the 'Yacas' Computer Algebra System

title: 'Ryacas: A computer algebra system in R' authors: - affiliation: 1 name: Mikkel Meyer Andersen orcid: 0000-0002-0234-0266 - affiliation: 1 name: Søren Højsgaard orcid: 0000-0002-3269-9552 date: "23 September 2019" bibliography: paper.bib tags: - cas - mathematics - symbolic mathematics - statistics - tex - latex affiliations: - index: 1 name: Department of Mathematical Sciences, Aalborg University, Denmark

Summary

Ryacas is an R [@R] package that enables a computer algebra system (CAS) within R via the open source CAS yacas [@Pinkus2002; @yacas], which is short for "yet another computer algebra system".

Ryacas includes both a high-level (symbol) interface using R objects like matrices and vectors as well as direct access to the underlying yacas such that the user can use the full yacas system, including for example defining new summation rules.

From a statistician's perspective, Ryacas does provide convenient tools directly in R like

sums,
limits,
differentiation,
integration,
symbolic matrices and vectors,
simplification, and
outputting in TeX format,

which are helpful in both research and teaching. With Ryacas, these tools are conveniently available from within R through Ryacas. However, it must be stressed that yacas is nowhere as powerful as the larger commercial CASs.

yacas is easy to use and extensible so that the user can define new rules, for example for simplification or summations. More information about yacas is available at http://www.yacas.org/.

Ryacas contains a number of vignettes that describe both how to use the high-level interface directly with R objects and how to use the underlying yacas system.

Ryacas contains a version of yacas which is bundled into Ryacas using Rcpp [@Rcpp]. This means that Ryacas can be installed like any other R package with no special installation steps being required.