Hey Andrew, Well, I've recently been looking at DisjointUnionEnumeratedSets (see https://trac.sagemath.org/ticket/22382) and came across this problem. The first issue is that DisjointUnionEnumeratedSets does not behave like an actual facade parent like it claims to be (at least with default values). The second is that __call__ calls a morphism, which in turn calls _element_constructor_ and expects a subclass of element to be returned. Thus for facade parents that want to return a tuple, this causes a problem (see the ticket).
Actually, looking at what you want more closely now, you want this to be a proper parent, so just pass the facade=False. This works with the current Sage: sage: tabs = DisjointUnionEnumeratedSets(Family(Partitions(3), lambda mu: cartesian_product([mu.standard_tableaux(),mu.standard_tableaux()])), facade= False) sage: s = StandardTableau([[1,2],[3]]) sage: (s,s) in tabs True sage: tabs((s,s)) ([[1, 2], [3]], [[1, 2], [3]]) Best, Travis On Wednesday, February 15, 2017 at 6:01:17 PM UTC-6, Andrew wrote: > > I am working with disjoint enumerated sets like the following > > sage: tabs = DisjointUnionEnumeratedSets(Family(Partitions(3), lambda mu: > cartesian_product([mu.standard_tableaux(),mu.standard_tableaux()]))) > sage: tabs[:] > [([[1, 2, 3]], [[1, 2, 3]]), > ([[1, 3], [2]], [[1, 3], [2]]), > ([[1, 3], [2]], [[1, 2], [3]]), > ([[1, 2], [3]], [[1, 3], [2]]), > ([[1, 2], [3]], [[1, 2], [3]]), > ([[1], [2], [3]], [[1], [2], [3]])] > > I need to be able to construct elements of this set from a tuple of > elements in the underlying sets but I can't work out a nice way to do this. > I thought that the following would work but it doesn't: > > sage: s = StandardTableau([[1,2],[3]]) > sage: (s, s) in tabs > True > sage: tabs( (s,s) ) > --------------------------------------------------------------------------- > NotImplementedError Traceback (most recent call last > ) > <ipython-input-67-3fe9605dd49e> in <module>() > ----> 1 tabs( (s,s) ) > > /usr/local/src/sage/src/sage/structure/parent.pyx in sage.structure.parent > .Parent.__call__ (build/cythonized/sage/structure/parent.c:9584)() > 934 self._element_init_pass_parent = guess_pass_parent > (self, self._element_constructor) > 935 except (AttributeError, AssertionError): > --> 936 raise NotImplementedError > 937 cdef Py_ssize_t i > 938 cdef R = parent_c(x) > > NotImplementedError: > > One way around this is the following, but I would guess that this is far > too inefficient to use inside an element_constructor method: > > sage: ss = tabs.unrank( tabs.rank( (s,s) ) ) > sage: type(ss) > <class > 'sage.sets.cartesian_product.CartesianProduct_with_category.element_class' > > > > Is there a better way to do his? > > Andrew > -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/d/optout.
