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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.
Ecological Drift under the UNTB
Hubbell's Unified Neutral Theory of Biodiversity.
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,
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.
Non-Ordered Vectors
Functionality for manipulating values of associative
maps. The package is a dependency for mvp-type
packages that use the STL map class: it traps
plausible idiom that is ill-defined (implementation-specific) and
returns an informative error, rather than returning a possibly
incorrect result. To cite the package in publications please use
Hankin (2022)
Efficient Evaluation of Quadratic Forms
A range of quadratic forms are evaluated, using efficient methods. Unnecessary transposes are not performed. Complex values are handled consistently.
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.
The Hyperdirichlet Distribution, Mark 2
A suite of routines for the hyperdirichlet distribution
and reified Bradley-Terry; supersedes the 'hyperdirichlet' package;
uses 'disordR' discipline
Ensemble Platform for Species Distribution Modeling
Functions for species distribution modeling, calibration and evaluation, ensemble of models, ensemble forecasting and visualization. The package permits to run consistently up to 10 single models on a presence/absences (resp presences/pseudo-absences) dataset and to combine them in ensemble models and ensemble projections. Some bench of other evaluation and visualization tools are also available within the package.