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Slug #120

LT over QQ: surprisingly slow

Added by John Abbott about 12 years ago. Updated almost 10 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
Various
Target version:
Start date:
03 Apr 2012
Due date:
% Done:

0%

Estimated time:
4.00 h
Spent time:

Description

The following should compute a LT ideal of a small ideal (using lex).
It takes longer than I would expect over QQ -- it is quite fast over ZZ/(p), and produces ideal(x,y,z^10).
Over QQ it is really too slow (>20mins on my current computer)... JAA thinks there may really be a bug.

  ring QQ = RingQQ();
  PolyRing P = NewPolyRing(QQ, symbols("x","y","z"), lex);
  RingElem x = indet(P,0);
  RingElem y = indet(P,1);
  RingElem z = indet(P,2);
  RingElem g1 = x*x*x +x*x*z +x*z;
  RingElem g2 = x*x*x +x*y*y +1;
  RingElem g3 = x*x +x*y*z +y*y*y;

  ideal I(g1,g2,g3);

  cout << "LT(I)=" << LT(I) << endl;

Estimated time is only for locating the problem; it will have to be updated when the root cause is discovered.


Related issues

Related to CoCoALib - Design #871: Redesign idealsNew2016-04-26

History

#1 Updated by John Abbott about 12 years ago

Here is another suspect starting ideal in QQ[x,y,z],Lex
[x^4 +x*y^2*z +y^4, x^3*y +x^2*z^2 +z^2]

#2 Updated by John Abbott about 12 years ago

My "noddy" program for computing GBases can do the whole computation in a few seconds...

#3 Updated by Anna Maria Bigatti over 11 years ago

  • Tracker changed from Bug to Slug
  • Subject changed from Surprisingly slow to LT over QQ: surprisingly slow

#4 Updated by Anna Maria Bigatti about 10 years ago

  • Target version set to CoCoALib-0.99533 Easter14

#5 Updated by Anna Maria Bigatti about 10 years ago

  • Category set to Various

#6 Updated by John Abbott about 10 years ago

  • Target version changed from CoCoALib-0.99533 Easter14 to CoCoALib-0.99534 Seoul14

#7 Updated by John Abbott almost 10 years ago

  • Target version changed from CoCoALib-0.99534 Seoul14 to CoCoALib-1.0

#8 Updated by John Abbott almost 8 years ago

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