Status: Accepted
Owner: smichr
Labels: Type-Defect Priority-Medium
New issue 2044 by smichr: log(exp(x)) != x unless x is real
http://code.google.com/p/sympy/issues/detail?id=2044
I see the following comment in the code or exponential.py:
+ #this doesn't work due to caching: :(
+ #elif isinstance(arg, exp) and arg[0].is_real:
+ #using this one instead:
+ elif isinstance(arg, exp):
So this means sympy is also breaking rules here, too, when computing
log(exp(x)) = x. It should only do so when x is real. Can anyone say what
the caching problem is and what it would take to get this aspect working
again? If you make the change to master you end up getting infinite
recursion in series computations.
Do limit calculations also need a "assume_positive" assumption to get
things to work?
--
You received this message because you are subscribed to the Google Groups
"sympy-issues" group.
To post to this group, send email to sympy-iss...@googlegroups.com.
To unsubscribe from this group, send email to
sympy-issues+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sympy-issues?hl=en.
