#8972: Inversion and fraction fields for power series rings
--------------------------+-------------------------------------------------
Reporter: SimonKing | Owner: AlexGhitza
Type: defect | Status: needs_review
Priority: major | Milestone: sage-4.4.2
Component: algebra | Keywords: power series ring, fraction field
Author: Simon King | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
--------------------------+-------------------------------------------------
Changes (by SimonKing):
* status: needs_work => needs_review
Comment:
Replying to [comment:17 SimonKing]:
> sage: y=y/x
OK, the last (hopefully the last...) patch fixes this. I was verifying the
timings for basic arithmetic (the timings without patches are posted
above), and here is the positive result:
{{{
sage: R.<x> = ZZ[[]]
sage: timeit('a=1/x')
625 loops, best of 3: 218 µs per loop
sage: timeit('a=(1+x)/x')
625 loops, best of 3: 228 µs per loop
sage: timeit('a=1/(1+x)')
625 loops, best of 3: 1.22 ms per loop
sage: timeit('a=(1+x)/(1-x)')
625 loops, best of 3: 1.24 ms per loop
sage: y = (3*x+2)/(1+x)
sage: y=y/x
sage: z = (x+x^2+1)/(1+x^4+2*x^3+4*x)
sage: z=y/x
sage: timeit('y+z')
625 loops, best of 3: 189 µs per loop
sage: timeit('y*z')
625 loops, best of 3: 92.6 µs per loop
sage: timeit('y-z')
625 loops, best of 3: 189 µs per loop
sage: timeit('y/z')
125 loops, best of 3: 7.1 ms per loop
}}}
Now, ready for review, and I'll do something else...
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8972#comment:18>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" 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/sage-trac?hl=en.
