Skip to content

1.1.0
Compare
Choose a tag to compare
@wilfwilson wilfwilson released this 25 Jan 16:17
v1.1.0
95e8478

This is a minor release that includes some new features and some performance improvements.

The following issues were resolved, pull requests merged, or new features added:

  • Issue #40: If bliss is used to compute the automorphism group of a digraph, then the size of the automorphism group is returned from bliss to GAP, and the group object in GAP immediately knows its size. In particular, it is not necessary to recalculate this size. This was reported and fixed in PR #278 by Chris Jefferson.

  • Issue #279: In the function HomomorphismDigraphsFinder, it is now possible to specify a subgroup of the automorphism group of the range digraph. This way, the automorphism group of the range digraph is not computed by HomomorphismDigraphsFinder. This can result in a performance improvement in some cases. This was reported and fixed in PR #285 by Finn Smith.

  • Issue #284: The function HomomorphismDigraphsFinder sometimes did not return any homomorphisms when the source digraph had exactly one vertex. This was caused by the data structures used by HomomorphismDigraphsFinder not being correctly initialised in this case. This issue was reported by Finn Smith and fixed by James D. Mitchell in PR #286.

  • In PR #283, Finn Smith added the new operation DigraphsRespectsColouring, which can be used to check whether a transformation or permutation between digraphs respects given colourings. New versions of IsDigraphHomomorphism, and friends, were added that accept colourings as arguments and which use DigraphsRespectsColouring.

  • The version of bliss included in Digraphs was updated to allow all of its data structures to be modified in-place rather than allocated and deallocated repeatedly. The function HomomorphismDigraphsFinder was modified to make use of this new functionality in bliss, and subsequently the performance of HomomorphismDigraphsFinder has been improved (particularly in cases where many homomorphisms between distinct small digraphs are found). This was done by James D. Mitchell in PR #282.

  • Some further minor performance improvements were made, and a compiler warning was fixed.

Assets 3
Loading