On Sat, Jun 23, 2012 at 10:59 AM, Aleksandar Makelov <[email protected]> wrote: > >
... >> The general comment, which is really a design issue >> more than anything else, is that I like the module structure laid >> out in Sage: >> http://www.sagemath.org/doc/reference/groups.html >> There is a separate module for all the "named" permutation >> groups (eg, the AlternatingGroup), of which there are 16 listed >> there. I am afraid that the perm_group module will get too >> huge quickly without some thought to a more modular >> structure. BTW, I wrote the sage module permgroup_named.py, >> >> http://www.sagemath.org/doc/reference/sage/groups/perm_gps/permgroup_named.html, >> and please feel free to take all you want and relicense it BSD >> with my permission. > > > Good, this is now addressed in my pull request for weeks 2-3: > https://github.com/sympy/sympy/pull/1377 Great work. Looks like good progress to me. When trying to implement the Rubik's cube group for testing, I ran into the following g1 = Permutation([[1, 3, 8, 6],[2, 5, 7, 4],[9,33,25,17],[10,34,26,18],[11,35,27,19]]) --------------------------------------------------------------------------- ValueError Traceback (most recent call last) /Users/wdj/pythonfiles/sympy/<ipython-input-6-08f78f951d6f> in <module>() ----> 1 g1 = Permutation([[1, 3, 8, 6],[2, 5, 7, 4],[9,33,25,17],[10,34,26,18],[11,35,27,19]]) /Users/wdj/pythonfiles/sympy/sympy/combinatorics/permutations.py in __new__(cls, *args, **kw_args) 365 temp = [int(i) for i in flatten(args[0])] 366 if set(range(len(temp))) != set(temp): --> 367 raise ValueError("Integers 0 through %s must be present." % len(temp)) 368 369 cform = aform = None ValueError: Integers 0 through 20 must be present. I assume this is because disjoint cycle notation is not yet completely implemented? >> >> >> I would also recommend splitting off permutation group homomorphisms, >> once you write them, into another module. ... > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/sympy/-/km-fcZm_MskJ. > > 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.
