On Fri, 07 Nov 2008 06:40:17 -0600 Jason Grout <[EMAIL PROTECTED]> wrote:
> > Burcin Erocal wrote: > > On Fri, 7 Nov 2008 03:26:35 -0800 > > "Mike Hansen" <[EMAIL PROTECTED]> wrote: > > > >> On Fri, Nov 7, 2008 at 3:14 AM, Jason Grout > >> <[EMAIL PROTECTED]> wrote: > >>>> plot( f(x=5), (y, -10,10)) > >>>> > >>>> plot( f(x=5,y=y), (y, -10,10)) > >>>> > >>>> plot( f(5,None), (y, -10,10)) > >>>> > >>>> plot( f(5,y), (y, -10,10)) > >>>> > >>>> g(y) = f(5,y) > >>>> plot(g, (y, -10,10)) > >>>> That last one seemed too verbose > >>> > >>> I guess you could also do: > >>> > >>> plot( lambda y: f(5,y), (y, -10,10)) > >>> > >>> but then you give up things like fast_float. > >> You didn't mention > >> > >> plot(f(5,y).function(y), (y, -10,10)) > >> > >> which is the one that'd be compatible with non-callable > >> expressions. > > > > If symbolic expressions cease to be callable, plot would need to be > > changed to handle these cases: > > > > sage: plot( x^2 ) > > > > This seems plausible, since at the moment we allow > > > > sage: plot( sin ) > > > > for usability. > > > > > > Going back to your example, f(5,y) would just return a symbolic > > expression, so > > > > sage: f(x,y)=2*x+3*y > > sage: plot( f(5,y), (y, -10,10)) > > > > would be equivalent to > > > > sage: plot( 10+3*y, (y, -10,10)) > > > > which would just work. > > > > > > The current syntax allows this: > > > > sage: f(x,y) = a*x + b*y > > sage: f(5) > > b*y + 5*a > > sage: f(5)(5) > > b*y + 25 > > > > > > I think the last line should be a syntax error. > > > I agree, since f was explicitly defined with variables x and y. > > f(5) should return a function g(y) = b*y+5*a > > I think this could be easily changed (just return a function that has > explicit variables, rather than just a symbolic expression). I would still like to check that the length of the arguments match, and raise an error if they don't. So, continuing the above example, sage: f(5) should raise an error. It might be better if sage: f(5, None) or sage: f(5,y) returned the function g(y) = b*y+5*a. Cheers, Burcin --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
