On Friday, January 8, 2016, Vincent Delecroix <20100.delecr...@gmail.com> wrote:
> That would still expose the method in the namespace. Having "2" or > "log(2)" not being symbolic constant is confusing! I would definitely > prefer an "_is_symbolic_constant". A confusing name not in the global namespace isn't much better. How about a rename that is clearer? Ideas is_named_constant is_famous_constant is_special_constant I like special in that this is sort of like a special function. > > On 08/01/16 16:20, Volker Braun wrote: > >> Maybe it should be renamed to .is_symbolic_contstant(), freeing up >> .is_constant() for you. >> >> >> On Friday, January 8, 2016 at 6:16:38 PM UTC+1, Daniel Krenn wrote: >> >>> >>> Dear all, >>> >>> from the method-name and also from the one-line description >>> "Return True if this symbolic expression is a constant." >>> of Expression.is_constant, I expected that this gives more or less the >>> same result as checking whether symbolic expression has an empty >>> .variables(). However, we have >>> sage: log(2).is_constant() >>> False >>> and also >>> sage: SR(2).is_constant() >>> False >>> only pi, e and that stuff is "constant". >>> I find this very confusing. Am I alone with this feeling? >>> >>> The above is also inconsistent to >>> sage: P.<p> = ZZ[] >>> sage: P(2).is_constant() >>> True >>> >>> Best wishes, >>> >>> Daniel >>> >>> PS: To be fair, after the one-line description, it is explained what it >>> really does: >>> This function is intended to provide an interface to query the >>> internal representation of the expression. In this sense, the word >>> "constant" does not reflect the mathematical properties of the >>> expression. Expressions which have no variables may return "False". >>> But the phrase "the internal representation of the expression" sounds >>> like the end user should not care about it... (i.e. this is_constant >>> could be an underscore-method...). >>> >>> PPS: At the moment (not having answers to this posting), my favourite >>> implementation would be something like >>> def is_constant(self): >>> return not self.variables() >>> >>> >> > -- > 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. > -- Sent from my massive iPhone 6 plus. -- 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.
