On Wed, May 4, 2016 at 1:07 PM, Johan S. R. Nielsen <santaph...@gmail.com> wrote: > Michael Orlitzky writes: >> I have a matrix m... how come, >> >> * m.rank gives me bullshit >> * m.rank() works >> * m.T() crashes >> * m.T works? > > This is in my mind the most compelling reason to phase out properties in > Sage. I think Erik makes many good points, but ultimately I think > consistency is more important. The problems with ? and tab-completion > seem manageable, so I leave that aside. > > In many ways, programming math is a software designers worst nightmare, > where designing the good API that is logical and works in all cases > quickly becomes daunting. Michael's example above is nice: the rank of a > matrix is an invariant, so it should just be a read-only property, just > like all the my-first-@property-tutorials tells us, right? But by that > logic, tons and tons of zero-argument methods should be read-only > properties in Sage. And if someone later on implements a clever > algorithm2 for computing the rank of certain types of matrices,
Indeed, right now there are several rank algorithms for matrices over QQ: Signature : m.rank(self, algorithm='modp') Docstring : Return the rank of this matrix. INPUT: * "algorithm" -- either "'modp'" (default) or "'flint'" or "'linbox'" > Properties are preciously little used in Sage. And I see no clear way of > using them in a consistent manner, in the type of objects that is Sage. > So I feel the rule of consistency tells us we should therefore not use > properties at all (perhaps except for the types of exceptions discussed > by Nicolas Thiery and Simon King). > > Best, > Johan > > -- > 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. -- William (http://wstein.org) -- 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.
