On 3/25/07, Kyle Schalm <[EMAIL PROTECTED]> wrote: > here is some behaviour i find rather weird. > > In [76]: w1,w2=QQ['w1,w2'].gens() > > now as i see it, w1 is a polynomial in one variable. indeed: > > In [77]: w1.variables() > Out[77]: [w1]
No, it is a polynomial in two variables. What it "is" is determined by its parent: sage: w1,w2=QQ['w1,w2'].gens() sage: parent(w1) Polynomial Ring in w1, w2 over Rational Field The definition of variables is that it returns the "list of variables ocuring in the poly". If that determined whether the poly were in 1 or 2 variables, then it would, e.g. be impossible to even define a constant polynomial -- since it wouldn't be a polynomial. > however, > > In [78]: w1(1) > <type 'exceptions.TypeError'>: x must be of correct length > > > whereas > > In [79]: w1(1,1) > Out[79]: 1 > > succeeds. i see why it's this way, but is it intentional (and a good > idea)? It is both intentional and definitely a good idea. It is one of the key ways that SAGE is different than say Maple or Mathematica, where an object should be totally determined by what it looks like (instead of some further information such as its parent). William --~--~---------~--~----~------------~-------~--~----~ 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://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
