#10752: Matrix pivots are cached, should be immutable
------------------------------+---------------------------------------------
Reporter: rbeezer | Owner: jason, was
Type: defect | Status: needs_work
Priority: minor | Milestone: sage-4.7
Component: linear algebra | Keywords: matrix pivots
Author: John Palmieri | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
------------------------------+---------------------------------------------
Changes (by jhpalmieri):
* status: needs_review => needs_work
Comment:
Right now I'm leaning away from the current patch and perhaps toward the
tuple approach. If I add a keyword (which I called "safe" so as not to
conflict with the "copy" function):
{{{
sage: A = random_matrix(QQ, 100)
sage: timeit('A.pivots(safe=True)')
625 loops, best of 3: 6.38 µs per loop
sage: timeit('A.pivots(safe=False)')
625 loops, best of 3: 3.13 µs per loop
sage: timeit('A.pivots(safe=False)')
}}}
Whereas if I use tuples as output (via another modification of the current
patch):
{{{
sage: A = random_matrix(QQ, 100)
sage: timeit('A.pivots(use_tuple=False)')
625 loops, best of 3: 3.14 µs per loop
sage: timeit('A.pivots(use_tuple=True)')
625 loops, best of 3: 3.55 µs per loop
sage: timeit('A = random_matrix(QQ, 100); A.pivots(use_tuple=False)')
25 loops, best of 3: 22.2 ms per loop
sage: timeit('A = random_matrix(QQ, 100); A.pivots(use_tuple=True)')
25 loops, best of 3: 22.2 ms per loop
}}}
I suppose using tuples may cause a slow-down in other places, but the
"pivots" method gets slowed down by maybe 10%, as opposed to copying the
list, which doubles the time.
I'm marking this as "needs work" because I'm not happy with the slowdown
in the current patch.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10752#comment:4>
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.
