#10591: Implement univariate polynomial rings over absolute number fields
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   Reporter:  lftabera       |       Owner:  tbd                                
    
       Type:  PLEASE CHANGE  |      Status:  new                                
    
   Priority:  major          |   Milestone:                                     
    
  Component:  PLEASE CHANGE  |    Keywords:  number fields, polynomials, 
performance
     Author:                 |    Upstream:  N/A                                
    
   Reviewer:                 |      Merged:                                     
    
Work_issues:                 |  
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 A specific implementation can improve a lot performance. At least for
 multiplication, addition and gcd.

 One approach is to implement Nuberfield(f)[x] more likely
 QQ[x][y].quotient(f(y))

 Note, with patch #10255
 {{{
 sage: K=QQ[x]['y']
 sage: y=K.gen()
 sage: L=K.quotient(y^16+y^5+y^4+y^3+y^2+y+1)
 sage: f=L(K.random_element(16,1500))
 sage: g=L(K.random_element(16,1500))
 sage: P=NumberField(x^16+x^5+x^4+x^3+x^2+x+1,'a')[x]
 sage: f1 = P.random_element(1500)
 sage: g1 = P.random_element(1500)
 sage: def nfpol_to_pari(f):
     return pari([c._pari_('a') for c in f.list()]).Polrev()
 ....:
 sage: fpari = nfpol_to_pari(f1)
 sage: gpari = nfpol_to_pari(g1)
 sage: %time _ = f*g
 CPU times: user 1.92 s, sys: 0.00 s, total: 1.92 s
 Wall time: 1.94 s
 sage: %time _ = f1*g1
 CPU times: user 20.29 s, sys: 0.04 s, total: 20.32 s
 Wall time: 20.34 s
 sage: %time _ = fpari*gpari
 CPU times: user 66.50 s, sys: 0.02 s, total: 66.52 s
 Wall time: 66.58 s
 sage: %time _=f+g
 CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
 Wall time: 0.01 s
 sage: %time _=f1+g1
 CPU times: user 0.02 s, sys: 0.00 s, total: 0.02 s
 Wall time: 0.02 s
 sage: %time _=fpari+gpari
 CPU times: user 0.01 s, sys: 0.00 s, total: 0.01 s
 Wall time: 0.01 s
 }}}

 Related tickets: #8558, #10255

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10591>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica, 
and MATLAB

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