I don't think the Indexed objects are real tensors. They were designed for use with the code generation module. It would be better to get this functionality with the new tensor module, I think (assuming my understanding of it is correct).
Aaron Meurer On Fri, Feb 7, 2014 at 2:30 PM, <[email protected]> wrote: > Hi, I was wondering if its possible to take derivatives with respect to > indexed symbols. For example, > >>>> from sympy.tensor import IndexedBase, Idx >>>> x = IndexBase('x') >>>> i, j = map(Idx, ['i', 'j']) >>>> x[i].diff(x[j]) > ValueError: Can't differentiate wrt the variable: x[j], 1 > > I'd like Sympy to return KroneckerDelta(i,j). > > -- > 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 http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. -- 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 http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
