Hi Matt You can use raw_input to get the function as string:
>> in = raw_input() E.g. the user would enter something like "sin(x)*log(x)". Then you can use the sympify function to convert this string into a sympy expression: >> expr = sympify(in) Now you need to find out what symbol the user used as variable. >> symbols = expr.atoms(Symbol) Hopefully just one symbol was used, but of course you will have to make sure. Then we want to get the derivative: >> s = symbols.pop() >> der = expr.diff(s) For the numerical computations you might want to do the following: >> f = lambdify(s, der) (For more information on lambdify read it's docstring) Now you can compute the numerical value of the derivative easily: >> f(1) 2.0 >> f(2) 2.6302769476946342 Hope this helps, Sebastian --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---