HAP

Homological Algebra Programming

Version 1.26
Released 2020-05-04

This project is maintained by Graham Ellis

Build Status Code Coverage

The HAP package for group cohomology and related functors

(C) Graham Ellis

HAP is a package for some calculations in elementary algebraic topology and the cohomology of groups. The initial focus of the library was on computations related to the cohomology of finite and infinite groups, with particular emphasis on integral coefficients. The focus has since broadened to include Steenrod algebras of finite groups, Bredon homology, cohomology of simplicial groups, and general computations in algebraic topology relating to finite CW-complexes, covering spaces, knots, knotted surfaces, and topics such as persitent homology arising in topological data analysis. A full description of the library can be found at http://hamilton.nuigalway.ie/Hap/www/ .

HAP is written almost entirely in the GAP language. A few of HAP’s (optional) functions rely on Polymake software (available from www.math.tu-berlin.de/polymake/) which should be installed so that it starts using the command “polymake” at the Linux prompt. A few (optional) functions rely on Singular software (available from https://www.singular.uni-kl.de/) which should be installed so that it starts using the command “singular” at the Linux prompt. A few (oprional) functions rely on Graphviz software (available from http://www.graphviz.org/).

Please send your bug reports to graham.ellis(at)nuigalway.ie .

Installing HAP

On a Linux machine with GAP (and optionally Polymake) installed, the HAP library can be loaded as follows:

  1. Change to the directory “pkg/Hap1.25/” .
  2. Edit the file “compile” so that: PKGDIR is equal to the path to the directory “pkg” where your GAP packages are stored; GACDIR is equal to the path to the directory where the GAP compiler “gac” is stored.
  3. Type “./compile” .

The next time HAP is loaded a compiled version will be loaded.