This is fine: sage: C = Conic([1,1,-1]) sage: C Projective Conic Curve over Rational Field defined by x^2 + y^2 - z^2 sage: C.rational_parameterization()
Scheme morphism: From: Projective Space of dimension 1 over Rational Field To: Projective Plane Curve over Rational Field defined by x^2 + y^2 - z^2 Defn: Defined on coordinates by sending (s : t) to (s^2 - t^2 : 2*s*t : s^2 + t^2) but this is not: sage: C = Conic([1027986085027861747937 , 722974121783, -604305613931]) sage: C Projective Conic Curve over Rational Field defined by 1027986085027861747937*x^2 + 722974121783*y^2 - 604305613931*z^2 sage: C.rational_parameterization() Scheme morphism: From: Projective Space of dimension 1 over Rational Field To: Projective Plane Curve over Rational Field defined by 1027986085027861747937*x^2 + 722974121783*y^2 - 604305613931*z^2 Defn: Defined on coordinates by sending (s : t) to (272561126856814943619672736316674281724159746275694018234 : 292362540189983749235664021894852879556406208063400253511743 : 483823403259473971100400534005871494692555156705) since (1) the point displayed does not lie on the conic and (2) it's only one point and the parametrization should involve quadratics in s and t, not be constant. Incidentally, the implementation calls Singular to do the work. I don't know if Singular itself has this bug. John -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.