On Thursday, June 2, 2011, John Cremona <john.crem...@gmail.com> wrote:
> 1. Are the matrices in these tests dense?

Yes, very.

> 2. How do the timings grow with the dimension?

I do not know.


>
> John
>
> On Thu, Jun 2, 2011 at 1:14 AM, William Stein <wst...@gmail.com> wrote:
>> On Wed, Jun 1, 2011 at 11:32 AM, B Saunders <saund...@udel.edu> wrote:
>>>
>>>>
>>>> When I wrote this code in 2007, for some range of matrix sizes and
>>>> bitsizes it was the fastest code in the world (even solidly beating
>>>> Magma, which was the fastest before)... mainly since IML is so damned
>>>> good.   I don't know what the current situation is.
>>>>
>>>>  -- William
>>>>
>>>>
>>> LinBox now has a Dixon based solver that I understand to be substantially
>>> similar to IML (including copy of key ideas in the IML implementation).
>>> Also, we have just reworked Wan's numeric-symbolic solver so that it is much
>>> more robust.  Some example timings are given in [1].  For example, on a full
>>> row rank 500 by 501 integer matrix with entries random in (-100, 100), a
>>> null space vector is computed in 1.09 sec using Dixon and 0.931 sec using
>>> numeric-symbolic iteration.
>>
>> I'm really glad that Linbox now has a Dixon solver!
>>
>> For completeness of this thread, I'll try the same benchmark with Sage 
>> (=IML).
>>
>> On my OS X core i7 2.6Ghz laptop (which uses the system ATLAS), this
>> benchmark takes 0.74 seconds.
>>
>> sage: A = random_matrix(ZZ,500,501,x=-100,y=100)
>> sage: time V = A.right_kernel()
>> CPU times: user 0.82 s, sys: 0.04 s, total: 0.86 s
>> Wall time: 0.74 s
>> sage: V.dimension()
>> 1
>>
>> On my Intel Xeon 2.6Ghz Linux server (single threaded ATLAS):
>>
>> sage: A = random_matrix(ZZ,500,501,x=-100,y=100)
>> sage: time V = A.right_kernel()
>> CPU times: user 2.47 s, sys: 0.03 s, total: 2.50 s
>> Wall time: 2.53 s
>>
>>
>> On my Opteron 2.6Ghz Linux server (single threaded ATLAS):
>>
>> sage: A = random_matrix(ZZ,500,501,x=-100,y=100)
>> sage: time V = A.right_kernel()
>> CPU times: user 0.87 s, sys: 0.02 s, total: 0.89 s
>> Wall time: 0.98 s
>>
>> This is all really just timing IML, plus conversions, plus IML's use of 
>> ATLAS.
>>
>>
>> Here's a bigger one (on the 2.6Ghz opteron):
>>
>> sage: A = random_matrix(ZZ,1000,1001,x=-100,y=100)
>> sage: time V = A.right_kernel()
>> CPU times: user 5.59 s, sys: 0.07 s, total: 5.66 s
>> Wall time: 5.66 s
>>
>>
>>  -- William
>>
>>
>>
>>>
>>> -dave
>>>
>>> [1] S, Wood, and Youse, Symbolic-Numeric Exact Rational Linear System
>>> Solver, to appear in ISSAC'11 next week.
>>>
>>> --
>>> You received this message because you are subscribed to the Google Groups
>>> "linbox-use" group.
>>> To post to this group, send email to linbox-...@googlegroups.com.
>>> To unsubscribe from this group, send email to
>>> linbox-use+unsubscr...@googlegroups.com.
>>> For more options, visit this group at
>>> http://groups.google.com/group/linbox-use?hl=en.
>>>
>>
>>
>>
>> --
>> William Stein
>> Professor of Mathematics
>> University of Washington
>> http://wstein.org
>>
>> --
>> To post to this group, send an email to sage-devel@googlegroups.com
>> To unsubscribe from this group, send an email to 
>> sage-devel+unsubscr...@googlegroups.com
>> For more options, visit this group at 
>> http://groups.google.com/group/sage-devel
>> URL: http://www.sagemath.org
>>
>
> --
> To post to this group, send an email to sage-devel@googlegroups.com
> To unsubscribe from this group, send an email to 
> sage-devel+unsubscr...@googlegroups.com
> For more options, visit this group at 
> http://groups.google.com/group/sage-devel
> URL: http://www.sagemath.org
>

-- 
William Stein
Professor of Mathematics
University of Washington
http://wstein.org

-- 
To post to this group, send an email to sage-devel@googlegroups.com
To unsubscribe from this group, send an email to 
sage-devel+unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sage-devel
URL: http://www.sagemath.org

Reply via email to