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This document describes the installation and usage of the code in this repository, both for the calculation of homology as well as for the S test.

Installation

the easiest way to install this package is by first installing the package devtools via install.package(devtools) followed by library(devtools) There might be a warning about missing Rtools. This can be ignored (for the purposes of this package) as they are unneccessary. Then, to install the package quhomology proper, run install_github("ansgarwenzel/quhomology") .

Usage

First, load the package via library(quhomology) The main calculations are done by running homology(degree,k,quandle) and degenerate_homology(degree,k), where k is the order of the rack/birack, degree is the degree of the homology group (that is, degree=2 for H_2) and quandle is a boolean variable as follows: TRUE calculates the quandle homology whereas FALSE calculates the rack homology. Finally, degenerate_homology calculates the degenerate homology group.

The package is set up to calculate the homology of the dihedral quandle. Should another quandle'S homology be calculated, the up_action and down_action functions have to be changed. For details, run ?up_action and ?down_action

S_test the second function of the package is a test whether a set of order k with a given up_action and down_action (change as required, see help pages for details) for this, change the actions as required and then run S_test(k)

Question/Problems? Send an email to ansgar.wenzel+quhomology(at)gmail.com

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Version

Install

install.packages('quhomology')

Monthly Downloads

34

Version

1.1.1

License

GPL (>= 3)

Maintainer

Last Published

May 10th, 2018

Functions in quhomology (1.1.1)

GaussianElimination

Calculation of Gaussian Form of a matrix.
output_results

Function that prints the calculated homology group to the screen
matrix_rank

Calculates the rank of a matrix.
smith

Smith Normal Form of a matrix.
up_action

The up action for a birack or biquandle.
check_f

Check if the function is bijective
check_more_push

Helper function for Smith Normal Form calculation.
check_permutations

Check if Switch is bijective.
all_combinations

Calculating all possible permutations
degenerate_homology

Calculates the degenerate Homology for a rack/birack.
boundary_names_degenerate

Calculation of degenerate boundary elements for boundary matrix
boundary_matrix

This function calculates a boundary matrix.
down_action

The down action for a birack or biquandle.
check_YB

Check Young Baxter Equation
push_down

Helper Function for Smith Normal Form calculation.
quhomology-package

Calculation of Homology groups of a rack/birack
row_space

Row Space of a Matrix.
rref

Reduced Row Echelon Form of a matrix
findX

Calculate the left row action matrix to turn a matrix into its Gaussian Form.
S_test

Testing of possible quandle/biquandle actions
boundary_names

Calculation of boundary elements for quandle and rack boundary matrix
boundary_matrix_degenerate

Calculation of boundary matrix for degenerate Homology.
find_S_result

Calculate the Switch
homology

Calculation of quandle and rack homology groups of a rack / birack.