[GAP Forum] New version 4.8 of GRAPE in GAP 4.9.2

[Leonard Soicher]

Dear GAP Forum,

I am pleased to announce that a new release of GRAPE, 
version 4.8, is available in GAP 4.9.2. 

This new version of GRAPE introduces new functionality for
proper vertex colouring and the computation of the chromatic
number and clique number of a (simple) graph. Also included is
a new function to construct Hamming graphs. 

An overview of changes introduced in GRAPE 4.8 is appended.

Regards,
Leonard

Main changes from GRAPE 4.7 to GRAPE 4.8
-----------------------------------------------------------

(1) New function: HammingGraph

(2) New operations: MaximumClique, MinimumVertexColouring 

(3) New attributes (which cannot be stored in a GRAPE graph record, but 
are declared as attributes rather than operations so as not to
conflict with the Digraphs package): CliqueNumber, ChromaticNumber 

(4) ConnectedComponent and ConnectedComponents are now operations 
rather than functions, to avoid conflicts with other developers.

(5) Enhanced functionality for function VertexColouring, which can 
now be used to determine whether a graph has a proper vertex k-colouring,
and if so, to return such a colouring.  

(6) Efficiency of the function VertexTransitiveDRGs improved for
transitive permutation groups having some orbitals which are not
self-paired.

(7) GRAPE HTML documentation now made with version 4.12 of tth, and
displays correctly on all browsers tested (thanks to Andries Brouwer
for pointing out the problem and to GAP Support for providing a solution). 

(8) The GRAPE HTML documentation links to the GAP reference manual now
work (thanks to Jerome Benoit for providing a solution).

(9) The default location for a user-installed bliss executable (if used) is 
now  ExternalFilename(DirectoriesSystemPrograms(),"bliss") 
(thank you to Jerome Benoit for suggesting this). 
However, the default location of the dreadnaut executable remains
ExternalFilename(DirectoriesPackagePrograms("grape"),"dreadnautB")
to run the included version in GRAPE of nauty/dreadnaut.

(10) Efficiency change to PartialLinearSpaces, to use exact cover
instead of clique search to classify "bundles".

(11) Fixed small efficiency bug in CompleteSubgraphsMain.