Hi Burcin: When using Sage for my work i makes heavy use of dictionaries to substitute values for derivatives of symbolic functions. Thanks for your help on fixing this bug for Sage 4.1.1.
Alex On Jun 8, 7:12 am, Burcin Erocal <bur...@erocal.org> wrote: > Hi Alex, > > On Sun, 7 Jun 2009 11:31:26 -0700 (PDT) > > > > Alex Raichev <tortoise.s...@gmail.com> wrote: > > > Hi all: > > > Upon upgrading to Sage 4.0, i can no longer make a dictionary with > > derivatives as keys (see below). Can someone please fix this? > > ---------------------------------------------------------------------- > > | Sage Version 4.0, Release Date: 2009-05-29 | > > | Type notebook() for the GUI, and license() for information. | > > ---------------------------------------------------------------------- > > sage: X= var('x,y') > > sage: f= function('f',*X); f > > f(x, y) > > sage: for x in X: > > ....: diff(f,x) > > ....: > > D[0](f)(x, y) > > D[1](f)(x, y) > > sage: d= {} > > sage: for x in X: > > ....: d[diff(f,x)] = 1 > > ....: > > <snip> > > > > > /Applications/sage/local/lib/python2.5/site-packages/sage/rings/ > > complex_interval_field.pyc in __call__(self, x, im) > > 286 > > 287 try: > > --> 288 return x._complex_mpfi_( self ) > > 289 except AttributeError: > > 290 pass > > > /Applications/sage/local/lib/python2.5/site-packages/sage/symbolic/ > > expression.so in sage.symbolic.expression.Expression._complex_mpfi_ > > (sage/symbolic/expression.cpp:5484)() > <snip> > > /Applications/sage/local/lib/python2.5/site-packages/sage/symbolic/ > > expression_conversions.pyc in derivative(self, ex, operator) > > 344 NotImplementedError: derivative > > 345 """ > > --> 346 raise NotImplementedError, "derivative" > > 347 > > 348 def arithmetic(self, ex, operator): > > > NotImplementedError: derivative > > I opened a ticket for this: > > http://trac.sagemath.org/sage_trac/ticket/6243 > > As I wrote on the ticket, I believe the correct fix is to change pynac > to handle more general numerical approximations. I will try to get this > done until the next release. > > There might be an easier fix by implementing the derivative method in > sage.symbolic.expression_conversions.Converter. Maybe Mike can comment > on that. > > Thanks. > > Burcin --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---