I think we should merge Kirpichev's fork into SymPy. He has fixed lots of issues with limits.
On Monday, 7 November 2016 21:40:08 UTC+1, Aaron Meurer wrote: > > Can you open an issue in the issue tracker for this? > > Aaron Meurer > > On Tue, Nov 1, 2016 at 3:32 PM, Rüdiger Braun <[email protected] > <javascript:>> wrote: > > Hi all! > > > > The following code > > > > (compana16) braun:~/git/compana16$ ipython > > Python 3.5.2 |Continuum Analytics, Inc.| (default, Jul 2 2016, > 17:49:02) > > Type "copyright", "credits" or "license" for more information. > > > > IPython 5.1.0 -- An enhanced Interactive Python. > > ? -> Introduction and overview of IPython's features. > > %quickref -> Quick reference. > > help -> Python's own help system. > > object? -> Details about 'object', use 'object??' for extra details. > > > > In [1]: import sympy > > > > In [2]: sympy.__version__ > > Out[2]: '1.0' > > > > In [3]: x = sympy.Symbol('x') > > > > In [4]: a = sympy.Symbol('a', positive=True) > > > > In [5]: f = sympy.exp(x*(-a-1)) * sympy.sinh(x) > > > > In [6]: f.limit(x, sympy.oo) > > Out[6]: oo > > > > > > > > produces false output. Correct is 0 > > I think it is somehow related to caching. If caching is turned off, > then > > the product in [5] cannot even be constructed. > > > > (compana16) braun:~/git/compana16$ export SYMPY_USE_CACHE='no' > > (compana16) braun:~/git/compana16$ ipython > > Python 3.5.2 |Continuum Analytics, Inc.| (default, Jul 2 2016, > 17:49:02) > > Type "copyright", "credits" or "license" for more information. > > > > IPython 5.1.0 -- An enhanced Interactive Python. > > ? -> Introduction and overview of IPython's features. > > %quickref -> Quick reference. > > help -> Python's own help system. > > object? -> Details about 'object', use 'object??' for extra details. > > > > In [1]: import sympy > > > > In [2]: sympy.__version__ > > Out[2]: '1.0' > > > > In [3]: x = sympy.Symbol('x') > > > > In [4]: a = sympy.Symbol('a', positive=True) > > > > In [5]: f = sympy.exp(x*(-a-1)) > > > > In [6]: g = sympy.sinh(x) > > > > In [7]: h = f*g > > > --------------------------------------------------------------------------- > > KeyError Traceback (most recent call > last) > > > /home/braun/miniconda3/envs/compana16/lib/python3.5/site-packages/sympy/core/assumptions.py > > > > in getit(self) > > 240 try: > > --> 241 return self._assumptions[fact] > > 242 except KeyError: > > > > KeyError: 'zero' > > > > During handling of the above exception, another exception occurred: > > > > KeyError Traceback (most recent call > last) > > > /home/braun/miniconda3/envs/compana16/lib/python3.5/site-packages/sympy/core/assumptions.py > > > > in getit(self) > > 240 try: > > --> 241 return self._assumptions[fact] > > 242 except KeyError: > > > > KeyError: 'zero' > > > > > > > > This goes on until a RecursionError kicks in. > > > > Best regards > > > > Rüdiger Braun > > > > -- > > 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] <javascript:>. > > To post to this group, send email to [email protected] > <javascript:>. > > 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/a1ca0361-3668-4ea0-b199-0ce08ab2a76b%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/c89c3a83-ecfc-49db-8746-2d19077560f0%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
