On Tue, Nov 8, 2011 at 4:15 PM, Roberto Colistete Jr. <[email protected]> wrote: > Hi, > > On SymPy 0.6.7 the 'diff' function works on lists. But on SymPy > 0.7.1 it doesn't, for example : > > In [1]: diff([cos(t), sin(t), exp(t), t) > --------------------------------------------------------------------------- > AttributeError Traceback (most recent call > last) > /home/roberto/<ipython-input-6-14d9fa9d6a32> in <module>() > ----> 1 diff([cos(t),sin(t),t],t) > > /usr/local/lib/python2.6/dist-packages/sympy/core/function.pyc in > diff(f, *symbols, **kwargs) > 1104 """ > 1105 kwargs.setdefault('evaluate', True) > -> 1106 return Derivative(f, *symbols, **kwargs) > 1107 > 1108 def expand(e, deep=True, modulus=None, power_base=True, > power_exp=True, \ > > /usr/local/lib/python2.6/dist-packages/sympy/core/function.pyc in > __new__(cls, expr, *symbols, **assumptions) > 672 if evaluate: > 673 if set(sc[0] for sc in symbol_count > --> 674 ).difference(expr.free_symbols): > 675 return S.Zero > 676 > > AttributeError: 'list' object has no attribute 'free_symbols'
^^^ I was getting this "no attribute 'free_symbols'" error couple times when I was trying to integrate something (I think). The error is not informative and the code should be refactored to produce a readable error message showing what is wrong and why. The above error message looks like a bug in sympy. Ondrej -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. 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.
