Hi, I am seeking opinion from sage-devel about the following issue on #6756. You can read the comments at
http://trac.sagemath.org/sage_trac/ticket/6756 In brief, new *diff* implementation has an option (not the default behaviour) by which an user can request to apply chain rule even with *diff* format. This is useful and sometime needed for many Physics problems. However, it is done under an assumption (documented with examples) that arguments of the function are independent for the purpose of applying chain rule. An example situation where above assumption is violated, is -------- sage: f(x,x).diff(x) -------- During implementation stage, I had posted this issue here http://groups.google.com/group/sage-devel/browse_thread/thread/c8d257981e3e3d98 Now my question: what is best approach to deal with this? Options are (1) Remove the feature entirely (as asked by Burcin) (2) Document the behaviour with examples how the output can be affected for the situations where the assumption is violated. Given Sage allows documented simplifications like ---------- sage: x/x 1 ---------- which is incorrect for x=0, it seemed natural to me go for option (2). However, I don't mind going for (1) if thats what sage-devels decide. Thanks, Golam --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
