polymake supports an extension system for writing and maintaining outside the distribution. Please contact the extension's authors if you have questions.
Lattice Polytopes and Toric Geometry
Matthias Walter: With this extension
you can test an integer matrix for total unimodularity. If the answer is “no”, it can return the row/column indices of a submatrix with |det| >= 2. It can also test for the related properties (strong) unimodularity, (strong) k-modularity and the Dantzig property. See here
for more information on implementation and theory.
Matthias Walter: This extension
can compute nonnegative slack matrix factorizations from extended formulations of polytopes and vice versa. See here
for more information.
Sven Herrmann: QuasiDec
. This extension contains an algorithm for computing the block decomposition of a quasi-median graph obtained from a set of partitions or a sequence alignment.
Sven Herrmann and Andreas Spillner: CoMRiT
. This extensions contains a new application metric introducing finite metric spaces as objects. The core feature is an algorithm to compute a realisation of a finite metric space using the tight-span, as described in Herrmann, Moulton, Spillner: Computing Realizations of Finite Metric Spaces.