Comment #43 on issue 1816 by ronan.l...@gmail.com: Adding partial derivatives and taking derivatives with respect to functions
http://code.google.com/p/sympy/issues/detail?id=1816
Aaron: it's a clear description of *some operation* (except that you didn't explain what kind of objects are allowed as arguments of .diff()), but I'm not sure that that operation is very useful and I'm quite sure that it has many puzzling and mathematically inconsistent consequences. I'd certainly prefer it if this tricky substitute-transform-backsubstitute were always done explicitly.
In any case, I think that these weird derivatives should be done only in diff(), so that Derivative objects keep their current behaviour and that code dealing with Derivative objects don't need to deal with the inconsistencies.
-- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to sympy-issues@googlegroups.com. To unsubscribe from this group, send email to sympy-issues+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.
