On Tue, Aug 28, 2012 at 6:34 PM, Chris Smith <[email protected]> wrote: > On Wed, Aug 29, 2012 at 3:58 AM, David Joyner <[email protected]> wrote: >> On Tue, Aug 28, 2012 at 5:54 PM, Chris Smith <[email protected]> wrote: >>>>>> from sympy.combinatorics import * >>>>>> Cycle()*(1,2)*(2,3) >>> [(1, 3, 2)] >> >> I call this L-R multiplication, because you "plug" 1 in from the left and >> see what cycle it belongs to by scanning L to R, then plug in the next >> smallest integer outside that cycle and see what cycle it belongs to, etc >> This agrees with Sage and Gap: > > OK, then whatever we call it hopefully the doc strings are clear that > I've written? >> >> sage: G = SymmetricGroup(5) >> sage: g1 = G([(1,2)]) >> sage: g2 = G([(2,3)]) >> sage: g1*g2 >> (1,3,2) >> > ... >>> Permutation([0, 2, 3, 1]) >> >> Which is (2,1,3). > > So we agree on the result. > > I'm very interested to see how using Permutaiton and Cycle feels to > you in the current branch. Any comment welcome. I think it's in good > shape now.
I did she:sympy davidjoyner$ git checkout smichr/combinatorics HEAD is now at b4bb058... permutation: add 0 to non-0-based perm but don't seem to have Cycle defined: >>> from sympy.combinatorics.perm_groups import PermutationGroup >>> from sympy.combinatorics import * >>> a = Cycle()*(1,2) Traceback (most recent call last): File "<console>", line 1, in <module> NameError: name 'Cycle' is not defined > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > 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/sympy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sympy" group. 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/sympy?hl=en.
