Comment #5 on issue 2723 by asmeurer: What should summation() do with non-integer limits?
http://code.google.com/p/sympy/issues/detail?id=2723

I just noticed that the result sympy gives is the same as the one you want, except at the point a = 0, where it's the same if you take the limit.

To see this, do

In [41]: c = summation(exp(a*x), (x, -S(1)/2, S(1)/2))

In [42]: expand(cancel(c.subs(exp(a/2), x)))
Out[42]:
    1
x + ─
    x

In [43]: expand(cancel(c.subs(exp(a/2), x))).subs(x, exp(a/2))
Out[43]:
 a    -a
 ─    ──
 2    2
ℯ  + ℯ

So the issue really isn't as bad is it originally seemed. Unfortunately, cancel() is not smart enough currently to do something like the above automatically (this should be a new issue).

--
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.

Reply via email to