On Jul 20, 2009, at 7:49 AM, Jason Grout wrote: > Stan Schymanski wrote: >> Thanks, Laurent. I figured that out, but it is quite tedious to >> have to >> go through each worksheet and change the soln[0][1] to soln[0].rhs(). >> There are other things that work differently now and of course >> there are >> new ways how to achieve the same results, which might be more >> elegant. >> However, I don't think this warrants confronting the user with the >> need >> to recode all her previous work. I remember an old thread where >> WAS and >> others expressed their concern for backwards compatibility and not >> breaking old code by upgrading to a new version, but this seems to >> have >> been abandoned for quicker progress, I suppose. > > Well, it was also a major, major release of Sage (i.e., the change to > 4.x version numbers). In particular, the functionality you described > was part of the major surgery in Sage internals that was the reason > for > changing the number to 4.x.
Despite being a major release, we do make a good effort for maintaining backwards compatibility. The internals of symbolics were completely rewritten, so I'm not surprised a couple of changes slipped through there. I'm surprised the solns object has changed, unless there's good reason we should probably change this back. As for .subs(locals()) I believe that was a bug and will be (was? I'm offline for the moment) fixed. > > I don't know the specifics of why the syntax doesn't work anymore, > or if > there are plans to support it, but there definitely is the possibility > of non-backwards compatible changes with major version number changes. > That's part of the reason for the major version number change---to > give > the user an indication that things may not work exactly as they > used to. > > Hence the need for at >> least a possibility to run the old versions in parallel with the new >> one, or a conversion tool for old notebooks. Multiple versions of Sage is totally possible, I have several of them on my laptop. You just have to start the notebook up with /path/to/ sage/version/sage -notebook distinct/notebook/dir - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
