On 2015-02-23, Jori Mantysalo <[email protected]> wrote: > Is there easy way to get "variables group" of a polynomial, or a list of > interchangeable variables? I.e. from > > a*b+c > > one would get > > [[a,b]] > > or from > > a*b+c*d > > either > > [[a,b],[c,d]] > > or a group isomorphic to D_4.
This is easy at least in the sense that this is the stabiliser of a set of subsets of the variables in the symmetric group S_n (assuming you have n variables). And GAP does this for you. The corresponding GAP command for your 2nd example would be gap> h:=Stabilizer(SymmetricGroup(4), [[1,2],[3,4]],OnSetsSets); Group([ (1,2), (1,3)(2,4) ]) gap> Size(h); 8 I don't know if this is properly wrapped in Sage. (Some GAP actions are wrapped just fine). You'd need to convert your polynomial into such a stricture, but this is easy. HTH, Dima -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
