Updates:
Status: Accepted
Comment #19 on issue 2052 by [email protected]: is_zero should default to
None, not False
http://code.google.com/p/sympy/issues/detail?id=2052
The problem is that False is returned for a numerical expression (not a
Float) that is definitely is zero:
e = -3 - sqrt(5) + (-sqrt(10)/2 - sqrt(2)/2)**2
e.is_zero
False
e.expand()
0
So at worst it should return None; at best, True. It's using a faulty
approach to answering a question (evalf at line 387 of assumptions) and
this should be fixed. It should either try expand the expression and then
return the answer if it becomes a Number, otherwise it should return None;
it should not use evalf to answer this question.
--
You received this message because you are subscribed to the Google Groups
"sympy-issues" 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-issues?hl=en.
