On Jun 28, 2008, at 9:33 AM, David Joyner wrote: > On Sat, Jun 28, 2008 at 11:00 AM, John Cremona > <[EMAIL PROTECTED]> wrote: >> >> It seems that what Dan Bump's instructions did not specify is what >> properties the class assigned to ._combinatorial_class must have. >> And it needs something which PermutationGroupElement does not have. >> >> Does that help? > > Okay. Maybe the best thing is to write a wrapper to GAP's GroupRing > function.
I disagree, using CombinatorialAlgebra will be a much better option. >>> Can anyone explain "AttributeError: type object >>> 'sage.groups.perm_gps.permgroup_element.Permutation' has no >>> attribute >>> 'count'" >>> (in words of two syllables or less, if possible:-)? Sure. It means that it's trying to use a method called "count" but the class "Permutation" found in sage/groups/perm_gps/ permgroup_element doesn't define one. What you need to do is make a method called count. Actually, looking at the code (and someone more familiar with sage- combinat should correct me) it looks like _combinatorial_class should be the Parent (i.e. the group) rather than the element. It would probably make sense to do something like > class PermutationGroupRing(CombinatorialAlgebra): > def __init__(self, R, G): > self.group = G > self._combinatorial_class = G # NOTE the change > self._one = G.identity() > self._name = 'Group ring of %s'%str(G) > self._prefix = '' > CombinatorialAlgebra.__init__(self, R) > def _multiply_basis(self, a, b): > c = a*b > return c and add a count method to the group class. - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
