Dear GAP-Forum,
Abishek wrote:
I want to know the algorithm used by GAP when a call to OrbitsDomain
(...)
function is made. The reference manual on page 396 only says that the
OrbitsDomain operation is often faster than orbits. I want to know
how/why
is it so.
OrbitsDomain *must* be given a domain which must be closed under the
group operation.
Orbits takes only seed points for the orbits, the orbits can be much
larger than the set of seed points.
`OrbitsDomain' can be faster as it can for example use an enumeration
of the full domain and use bit lists to remember which points have
been touched. `Orbits' instead must check all seed points whether
they are contained in the orbits found so far.
The reason for having these two operations is that `Orbits' (with
this syntax) was available in GAP3 and therefore has to be available
for compatibility reasons. However now we realize that the syntax of
`OrbitsDomain' in general permits a more efficient operation.
If you write new code I'd recommend you use `OrbitsDomain'.
Best wishes,
Alexander Hulpke
_______________________________________________
Forum mailing list
[email protected]
http://mail.gap-system.org/mailman/listinfo/forum
