Thanks! On Saturday, May 28, 2022 at 2:02:53 AM UTC-5 Nils Bruin wrote:
> Actually, this case is fully covered by > > https://trac.sagemath.org/ticket/32161 > > which is, unfortunately, stalled on what looks like a non-trivial problem > with a more general solution. Given that the problem arises again here, > perhaps it's worth accepting first a more limited solution and just stick > with errors on non-constant summation bounds. > > On Saturday, 28 May 2022 at 08:51:37 UTC+2 Nils Bruin wrote: > >> The bug is perhaps concisely illustrated with the following: >> >> sage: var('k,n') >> (k, n) >> sage: function('f') >> f >> sage: sum(f(x,k),k,1,n).diff(x) >> diff(f(x, k), x)*D[0](sum)(f(x, k), k, 1, n) >> >> it shows that sage doesn't have a differentiation rule in place for >> symbolic sums and just applies the chain rule on the first argument (and >> undoubtedly on the others, but those are constants in x). I would expect >> that there is a ticket lying around about this (some care needs to be taken >> to do something sensible with the other arguments as well), but I wasn't >> able to locate one. >> On Saturday, 28 May 2022 at 00:41:07 UTC+2 summers...@gmail.com wrote: >> >>> Hello, Sage Developers, >>> >>> I want to calculate the symbolic differentiation of a variable in an >>> expression with a sum of N unknown variables, and it seems sage cannot >>> handle it. I posted my question in >>> https://ask.sagemath.org/question/62451/how-to-symbolic-differentiate-a-sum-of-n-unknown-variables/ >>> >>> , and the answer says it is a bug in sage. How can I report a bug? Is this >>> bug already reported somewhere? >>> >>> Thanks, >>> >> -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/b68d22bc-50a2-4707-ae0d-12b835361c77n%40googlegroups.com.
