Hi Chris, This is a very old issue, #879. I tried to tackle it once, a long time ago, removing the non-implemented raise and chasing the problems that appear futher down the series logic (it gets into some infinite loops), but the series code is quite complicated and I never got it to work. I think to really solve it would require some serious clean up of the series logic. I don't think it is really needed to solve first #1620 and #1688 as stated in the issue dependencies.
The last stuff I tried is in my branch 879 (https://github.com/renatocoutinho/sympy/commits/879). Best regards, Renato On Sat, Mar 9, 2013 at 4:19 PM, smichr <smi...@gmail.com> wrote: > f(x) = f(x0) + (x-x0)*f(x).diff(x)|x=x0 + .... > > Is there any reason not to allow that rhs as the return for >>>> f(x).series(x) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "sympy\core\expr.py", line 2341, in series > s = self.subs(x, rep).series(x, x0=0, n=n, dir='+') > File "sympy\core\expr.py", line 2354, in series > s1 = self._eval_nseries(x, n=n, logx=None) > File "sympy\core\function.py", line 447, in _eval_nseries > supported.''')) > NotImplementedError: > series for user-defined functions are not supported. > > Maybe it could return something like this: > >>>> def fseries(eq, x0, n): > ... return Add(*[(x - x0)**i*Subs(eq.diff(x, i), x, x0) for i in range(n + > 1)]) > >>>> pprint(fseries(f(x), 1, 2).doit()) > / 2 \| > 2 | d || /d \| > (x - 1) *|---(f(x))|| + (x - 1)*|--(f(x))|| + f(1) > | 2 || \dx /|x=1 > \dx /|x=1 > > -- > 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 sympy+unsubscr...@googlegroups.com. > To post to this group, send email to sympy@googlegroups.com. > Visit this group at http://groups.google.com/group/sympy?hl=en. > 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
