Regarding the ValueError, this is expected behavior. You can only take derivatives with respect to symbols and simple undefined functions (like f(x)). See http://docs.sympy.org/latest/modules/core.html#sympy.core.function.Derivative
Aaron Meurer On Fri, Nov 11, 2016 at 1:15 PM, Riccardo Rossi <[email protected]> wrote: > ping! > > any more possible feedback on this? > > thx in advance > Riccardo > > On Friday, October 14, 2016 at 10:53:27 AM UTC+2, Riccardo Rossi wrote: >> >> Dear List, >> >> i am writing since i would like to define the output of the derivative of >> a function, and i don't have a clue of how to achieve it >> >> to explain what i wish to do, let's consider the following script >> >> from sympy import * >> >> u = symbols('u') >> der = symbols('der') >> e = symbols('e', cls=Function)(u) >> s = symbols('s', cls=Function)(e) >> Derivative(e,u) = der #essentially i would like to teach to sympy to use a >> symbol for the Derivative >> ---> but here i get "SyntaxError: can't assign to function call" >> >> print(diff(e,u)) >> print(diff(s,e)) >> print(diff(s,u)) #here i would like "der" to be replaced within the chain >> rule >> >> any suggestion would be very welcome... >> >> regards >> Riccardo >> >> > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/7211b6bb-a8cc-48f5-8252-3faf94dcceb0%40googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6L%3DjVa9cHGgRzbVz_nuJutTVZje_VDA40GpuNJGQxS1tA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
