On Dec 19, 2012, at 12:44 PM, John Cremona wrote:
--- Charles Bouillaguet http://www.lifl.fr/~bouillaguet/ > I suggest adding to the documentation of A.coordinates() that it works > also if the given element is in the ambient space, with an example of > that. In concrete terms you need the element to be an F-linear > combination of the generators where F is the fraction field of the > base ring R, and not just an R-linear combination. > > This functionality is useful (I have used it in some number field > functions) and I would not want it removed. Well, you could always access it through: R.ambient_vector_space().coordinates( x ) One problem I can see is "what to do when the ambient vector space is not defined?" (this happens when the ring is not a PID, because then its fraction field is not defined). Examples include: sage: R.<x,y> = QQ[] sage: I = (x*y) * R sage: Q = R.quotient( I ) sage: M = Q^3 sage: M.ambient_vector_space() # BOOM This is now : http://trac.sagemath.org/sage_trac/ticket/13853 --- Charles Bouillaguet http://www.lifl.fr/~bouillaguet/ > John > > >> --- >> Charles Bouillaguet >> http://www.lifl.fr/~bouillaguet/ >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sage-devel" group. >> To post to this group, send email to sage-devel@googlegroups.com. >> To unsubscribe from this group, send email to >> sage-devel+unsubscr...@googlegroups.com. >> Visit this group at http://groups.google.com/group/sage-devel?hl=en. >> >> > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To post to this group, send email to sage-devel@googlegroups.com. > To unsubscribe from this group, send email to > sage-devel+unsubscr...@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To post to this group, send email to sage-devel@googlegroups.com. To unsubscribe from this group, send email to sage-devel+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en.
