On Jan 18, 2008 9:48 AM, Robert Miller <[EMAIL PROTECTED]> wrote: > > > >> Let A be a matrix not over ZZ or QQ: > > > > >> A.adjoint() > > >> A.inverse() > > > > >> are not implemented. > > > > > I don't think they should be. There are already (at least) 3 ways > > > to do this: > > > > Wait a sec.... I agree with David K on the adjoint issue. The adjoint > > doesn't require the fraction field to even be constructed, and it > > makes perfect sense over non-domains. > > > > > sage: A = random_matrix(ZZ,2) > > > sage: ~A > > > > > [ 1/34 1/17] > > > [-6/17 5/17] > > > sage: A.__invert__() > > > > > [ 1/34 1/17] > > > [-6/17 5/17] > > > sage: A^(-1) > > > > > [ 1/34 1/17] > > > [-6/17 5/17] > > > > I vaguely recall being stung several times by the lack of an inverse > > () method. For someone who doesn't know python that well, neither ~ > > nor __invert__ are obvious alternatives. I don't think it would hurt > > at all to have an inverse() method. > > I actually think both should be methods, just because ~ and ^(-1) > don't show up on tab completion...
If you learn about ~ or ^(-1) once -- e.g., in the Sage or Python tutorial or anywhere else -- it will work uniformly everywhere. If you learn about .inverse() or .invert() it will work every once in a while in certain parts of the Sage library itself only, and will confusingly not work in a lot of other cases. It makes a lot of sense to have an adjoint method, etc., but having explicitly named methods for something that Python already provides a lot of infrastructure for will increase confusion and frustration in the long run. -- 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://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
