On Sep 7, 1:34 pm, tvn <[email protected]> wrote: > Hi John and Jason, thanks -- the inject_variables() did what I > want. > > I have another question below and hope you can help > > what if I already have create a function call f = x - y as below > > sage: vs = var('x y') > sage: f = x - y > sage: type(f) > <type 'sage.symbolic.expression.Expression'>
The expression f is not a function, but a symbolic expression. It is callable, though sage: f(x=1,y=1) 0 sage: g(x,y)=x-y sage: type(g) <type 'sage.symbolic.expression.Expression'> OK, so that doesn't give it away. But: sage: g(1,1) 0 (Note that there is no need to specify the names of the variables. Try that with f and you'll get a deprecation warning.) Anyway, for your question: sage: F=QQ['x','y'](f) sage: F x - y sage: type(F) <type 'sage.rings.polynomial.multi_polynomial_libsingular.MPolynomial_libsingular'> It's not a "polydict", but I think all dictionary functionality is present on F as well. I haven't succeeded in creating a "polydict" bivariate polynomial ring over Q. You can get a a "polydict" ring by asking for a polynomial ring over a more exotic base ring: sage: type(PolynomialRing(FractionField(QQ['t']),['x','y'])) <class 'sage.rings.polynomial.multi_polynomial_ring.MPolynomialRing_polydict_domain'> -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
