[GAP Forum] Future developments for the DESIGN Package

Leonard Soicher l.h.soicher at qmul.ac.uk
Wed Apr 26 12:14:14 BST 2006


Dear Design Developers, Dear GAP-Forum,

This message is to inform you of developments for a future release of 
the DESIGN Package for GAP. 

The functionality is being improved to allow for more straightforward
construction of block designs, such as those formed from group orbits
of blocks, and derived and residual designs.  Moreover, greater use of
(new and old) theoretical knowledge is being used in the  BlockDesigns
function for more efficient discovery and classification of block designs
with given properties.  Also, the documentation is being upgraded.

ONE WARNING: I plan to remove the undocumented option to  BlockDesigns
for it to compute only the resolvable and simple block designs with the
given properties. This would be a useful option if it worked efficiently,
but at present to compute resolvable designs (using the DESIGN package)
it seems to be usually more efficient to compute all block designs with
the given properties and then to filter out the resolvable ones. I'm
sure it is possible to do better than this, but probably not with the
current setup.  If the  "resolvable and simple" feature is essential
to your work then I would be interested to hear about it, and might
reconsider my decision to remove this cumbersome "feature".  In due
course I may try to write a more efficient implementation of an ability
to produce only resolvable block designs with given properties.

Regards,
Leonard Soicher



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