The Lorentz Transform in Relativistic Physics

The Lorentz transform in special relativity; also the gyrogroup structure of three-velocities. Performs active and passive transforms and has the ability to use units in which the speed of light is not unity. Includes some experimental functionality for celerity and rapidity. For general relativity, see the 'schwarzschild' package.

The Exterior Calculus

Provides functionality for working with tensors, alternating forms, wedge products, Stokes's theorem, and related concepts from the exterior calculus. Uses 'disordR' discipline (Hankin, 2022, ). The canonical reference would be M. Spivak (1965, ISBN:0-8053-9021-9) "Calculus on Manifolds". To cite the package in publications please use Hankin (2022) .

A Multivariate Emulator

A multivariate generalization of the emulator package.

Knot Diagrams using Bezier Curves

Makes visually pleasing diagrams of knot projections using optimized Bezier curves.

The Weyl Algebra

A suite of routines for Weyl algebras. Notation follows Coutinho (1995, ISBN 0-521-55119-6, "A Primer of Algebraic D-Modules"). Uses 'disordR' discipline (Hankin 2022 ). To cite the package in publications, use Hankin 2022 .

Antiassociative Algebra

Methods to deal with the free antiassociative algebra over the reals with an arbitrary number of indeterminates. Antiassociativity means that (xy)z = -x(yz). Antiassociative algebras are nilpotent with nilindex four (Remm, 2022, ) and this drives the design and philosophy of the package. Methods are defined to create and manipulate arbitrary elements of the antiassociative algebra, and to extract and replace coefficients. A vignette is provided.

Setup and connect to 'OpenTripPlanner'

Setup and connect to 'OpenTripPlanner' (OTP) < http://www.opentripplanner.org/>. OTP is an open source platform for multi-modal and multi-agency journey planning written in 'Java'. The package allows you to manage a local version or connect to remote OTP server to find walking, cycling, driving, or transit routes. This package has been peer-reviewed by rOpenSci (v. 0.2.0.0).

Arbitrary Dimensional Clifford Algebras

A suite of routines for Clifford algebras, using the 'Map' class of the Standard Template Library. Canonical reference: Hestenes (1987, ISBN 90-277-1673-0, "Clifford algebra to geometric calculus"). Special cases including Lorentz transforms, quaternion multiplication, and Grassmann algebra, are discussed. Vignettes presenting conformal geometric algebra, quaternions and split quaternions, dual numbers, and Lorentz transforms are included. The package follows 'disordR' discipline.

Manipulate Virtual Functions

If f <- function(x){x^2} and g <- function(x){x+1} it is a constant source of annoyance that "f+g" is not defined. Package 'vfunc' allows you to do this, and we have (f+g)(2) returning 5. The other arithmetic operators are similarly implemented. A wide class of coding bugs is eliminated.

The Complex Multivariate Gaussian Distribution

Various utilities for the complex multivariate Gaussian distribution and complex Gaussian processes.