#16116: Multiplication of dense cyclotomic matrices should be faster
-------------------------------------------------+-------------------------
       Reporter:  jipilab                        |        Owner:
           Type:  enhancement                    |       Status:  new
       Priority:  major                          |    Milestone:  sage-7.0
      Component:  number fields                  |   Resolution:
       Keywords:  cyclotomic field, matrix,      |    Merged in:
  multiplication, benchmark, days57              |    Reviewers:
        Authors:                                 |  Work issues:
Report Upstream:  N/A                            |       Commit:
         Branch:                                 |     Stopgaps:
   Dependencies:                                 |
-------------------------------------------------+-------------------------

Comment (by vdelecroix):

 At least on sage-7.0.beta2, wrapping GAP matrices for the examples
 mentioned in the ticket description will not bring any magic
 {{{
 sage: M = m._libgap_()
 sage: %timeit A = M^2
 1000 loops, best of 3: 181 µs per loop
 sage: %timeit A = M^3
 1000 loops, best of 3: 456 µs per loop
 }}}
 versus
 {{{
 sage: %timeit a = m^2
 1000 loops, best of 3: 298 µs per loop
 sage: %timeit a = m^3
 1000 loops, best of 3: 690 µs per loop
 }}}
 We are below x2 speedup. But in this example the matrix is small and
 coefficients relatively dense (~25 nonzero coefficients). Though, the gain
 is significant with 10x10 dense matrices with small coefficients
 {{{
 sage: m1 = matrix(10, [E(randint(2,3)) for _ in range(100)])
 sage: m2 = matrix(10, [E(randint(2,3)) for _ in range(100)])
 sage: %timeit m1*m2
 100 loops, best of 3: 4.51 ms per loop
 sage: %timeit M1*M2
 1000 loops, best of 3: 329 µs per loop
 }}}
 We might update the ticket description accordingly. Two concrete
 propositions are:
 - below a certain threshold (to be determined) use generic matrices for
 cyclotomic fields
 - wrap GAP matrices for UCF
 What do you think?

--
Ticket URL: <http://trac.sagemath.org/ticket/16116#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 unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.

Reply via email to