Hi all,
I am getting some weird errors doing computations with groups
algebras. Here is an example:
I create an element of the group algebra:
sage: G = SymmetricGroup(3)
sage: A = GroupAlgebra(G, QQ)
sage: c = sum(1/x.order()*A(x) for x in G)
sage: c
() + 1/2*(2,3) + 1/2*(1,2) + 1/3*(1,2,3) + 1/3*(1,3,2) + 1/2*(1,3)
If I multiply c with itself, it works:
sage: c*c
71/36*() + 5/3*(2,3) + 5/3*(1,2) + 55/36*(1,2,3) + 55/36*(1,3,2) +
5/3*(1,3)
However, if I take an element of the group and coerce into the group
algebra, this is what I get:
sage: g = G("(1,2,3)")
sage: C*A(g)
---------------------------------------------------------------------------
TypeError Traceback (most recent call
last)
/home/network/jlopez/SAGE_Lie/<ipython console> in <module>()
/scratch/sage/local/lib/python2.6/site-packages/sage/structure/
element.so in sage.structure.element.RingElement.__mul__ (sage/
structure/element.c:11336)()
/scratch/sage/local/lib/python2.6/site-packages/sage/structure/
coerce.so in sage.structure.coerce.CoercionModel_cache_maps.bin_op
(sage/structure/coerce.c:6990)()
TypeError: unsupported operand parent(s) for '*': 'Group algebra of
group "AlternatingGroup(5)" over base ring Rational Field' and 'Group
algebra of group "SymmetricGroup(3)" over base ring Rational Field'
To make it even weirder, if instead of "*" one uses "_mul_" everything
works:
sage: c._mul_(A(g))
1/3*() + 1/2*(2,3) + 1/2*(1,2) + (1,2,3) + 1/3*(1,3,2) + 1/2*(1,3)
Any idea on what's going on here?
Cheers
J
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