I don't think it is a bug (since the group could be infinite), but if I'm wrong and it is, how would you suggest it be fixed?
In any case, for your case you can use finite fields: sage: M1 = matrix(GF(3),2,[[-1,0],[0,1]]) sage: M2 = matrix(GF(3),2,[[1,0],[0,-1]]) sage: M3 = matrix(GF(3),2,[[-1,0],[0,-1]]) sage: MG = MatrixGroup([M1, M2, M3]) sage: MG.order() 4 sage: MG.list() [[1 0] [0 1], [1 0] [0 2], [2 0] [0 1], [2 0] [0 2]] (Here -1 is represented by 2.) Or you can use GAP: sage: g1 = gap([[-1,0],[0,1]]) sage: g2 = gap([[1,0],[0,-1]]) sage: g3 = gap([[-1,0],[0,-1]]) sage: gens = gap([g1,g2,g3]) sage: G = gens.Group() sage: G.Size() 4 sage: G.Elements() [ [ [ -1, 0 ], [ 0, -1 ] ], [ [ -1, 0 ], [ 0, 1 ] ], [ [ 1, 0 ], [ 0, -1 ] ], [ [ 1, 0 ], [ 0, 1 ] ] ] On Wed, Feb 11, 2009 at 3:48 PM, john_perry_usm <[email protected]> wrote: > > Hi, > > Is this a bug or is it expected behavior? > > sage: M1 = matrix(ZZ,2,[[-1,0],[0,1]]) > sage: M2 = matrix(ZZ,2,[[1,0],[0,-1]]) > sage: M3 = matrix(ZZ,2,[[-1,0],[0,-1]]) > sage: MG = MatrixGroup([M1, M2, M3]) > sage: MG.order() > 4 > sage: MG.list() > Traceback (click to the left for traceback) > ... > AttributeError: 'sage.rings.integer_ring.IntegerRing_class' object > has > no attribute 'prime_subfield' > > thanks > john perry > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] 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 -~----------~----~----~----~------~----~------~--~---
