On Tue, Jul 21, 2009 at 3:03 PM, Golam Mortuza Hossain<gmhoss...@gmail.com> wrote: > > Hi, > > On Mon, Jul 20, 2009 at 8:31 PM, Robert > Bradshaw<rober...@math.washington.edu> wrote: >>> On Sun, Jul 19, 2009 at 3:11 PM, William Stein<wst...@gmail.com> >>> wrote: >>>>>> Or should we just restore old "diff" by simply sub-classing it >>>>>> from SFunction like what is being done for "integration" >>>>>> and others? >>>> >>>> At first glance doing this sounds like a really good idea. How hard >>>> would it be for you to make a mock-up prototype of this to more >>>> clearly demonstrate it? I'm definitely not opposed. >>> >>> OK, here is a prototype implementation. >>> >>> This is based on the principle that we stop applying chain rule >>> when we hit a symbolic function and whose derivative isn't defined >>> in sage/pynac. >> >> Excellent idea! > > Thanks Robert. > > Its now up to Sage policy maker to decide whether to continue > with pynac fderivative.
Well I'm a policy maker and I vote +1 to you continuing with this line. As far as I can tell all the people involved with writing pyanc (me, Mike Hansen, and Burcin), don't use formal derivatives at all for any of our research/work. We just implemented something because other people need it and to finish the switch over. Several people on this list, including Golam, *do* need and use formal derivatives for their research. So go for it! William > > Inability to substitute the argument of D[] has ensured that > I am forced out from using new sage symbolics for my own work. > > > Cheers, > Golam, > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
