#10544: LLL reduced kernel bases are not always correct
------------------------------+---------------------------------------------
   Reporter:  rbeezer         |       Owner:  jason, was
       Type:  defect          |      Status:  new       
   Priority:  major           |   Milestone:  sage-4.6.2
  Component:  linear algebra  |    Keywords:            
     Author:                  |    Upstream:  N/A       
   Reviewer:                  |      Merged:            
Work_issues:                  |  
------------------------------+---------------------------------------------

Comment(by wjp):

 After discussion at days27, it seems this is an LLL parameter mismatch:


 {{{
 in gp:

 ? ??qflll
 qflll(x,{flag = 0}):

    LLL algorithm applied to the columns of the matrix x.   The columns of
 x may
 be linearly dependent.  The result is a unimodular transformation matrix T
 such
 that  x  .T  is  an  LLL-reduced  basis  of the lattice generated by the
 column
 vectors of x.  Note that if x is not of maximal rank T will not be square.
 The
 LLL parameters are (0.51,0.99),  meaning that the Gram-Schmidt
 coefficients for
 the  final  basis satisfy mu_{i,j} <= |0.51|,  and the Lov\'{a}sz's
 constant is
 0.99.
 }}}


 {{{
 sage: BB.is_LLL_reduced(eta=.51)
 True
 }}}

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10544#comment:2>
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.

Reply via email to