"Nicolas M. Thiery" <nicolas.thi...@u-psud.fr> writes: > Hi Martin! > > On Wed, Jul 13, 2011 at 12:22:50PM +0200, Martin Rubey wrote: >> Martin Rubey <martin.ru...@math.uni-hannover.de> writes: >> > I have a basis and two CombinatorialFreeModules over this basis, say one >> > over QQ and the other over QQ[q]. I'd like to convert elements from the >> > first into the second. Is there a built-in way to do this, or do I have >> > to iterate over the coefficients? >> >> Sorry, I mis-asked: should have been tensor products of >> CombinatorialFreeModules. > > sage: phi = A.module_morphism(B.monomial) > sage: phi(x) > > where A and B are respectively the source and target free module > (tensor product or not) should do the job.
Hm, and now I have a similar problem: how to do it in the other direction? I.e., I have a map from QQ[q] to QQ and want to use it to construct an element in a module over QQ given an element over QQ[q]... Hm, I just found from_vector. sage: R.<q> = QQ[] sage: F1 = CombinatorialFreeModule(R, ['a','b','c']) sage: F2 = CombinatorialFreeModule(QQ, ['a','b','c']) sage: def phi(p): return p.subs(q=1) sage: f = F1.an_element().map_coefficients(phi) sage: F2.from_vector(f.to_vector()) wouldn't F2(f) be nicer? Martin -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To post to this group, send email to sage-combinat-devel@googlegroups.com. To unsubscribe from this group, send email to sage-combinat-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en.
