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Bug #1416

IdealOfProjectivePoints and MinGens

Added by Anna Maria Bigatti about 4 years ago. Updated about 4 years ago.

Status:
Closed
Priority:
Normal
Assignee:
Anna Maria Bigatti
Category:
Maths Bugs
Target version:
CoCoALib-0.99700
Start date:
14 Feb 2020
Due date:
% Done:

100%

Estimated time:
2.01 h
Spent time:
1.40 h

Description

Juan Migliore found this weird bug:

/**/ A := GenericPoints(R,6,7000);
/**/ K := IdealOfProjectivePoints(R,mat(A));
/**/ MinGens(K);  -- gives []

Related issues

Related to CoCoALib - Feature #374: Porting "IdealOfProjectivePoints"Closed2013-06-18

Related to CoCoALib - Design #1255: Ideals with trivial GBasisNew2019-03-11

Related to CoCoA-5 - Bug #1420: IdealOfProjectivePoints and MinGens: problem with CoCoA_ASSERTClosed2020-02-18

Related to CoCoALib - Feature #1433: HilbertDriven Buchberger AlgorithmNew2020-03-04

History

#1 Updated by Anna Maria Bigatti about 4 years ago

  • Related to Feature #374: Porting "IdealOfProjectivePoints" added

#2 Updated by Anna Maria Bigatti about 4 years ago

  • Subject changed from IdealOfProjectivePoints and MinPoly to IdealOfProjectivePoints and MinGens

#3 Updated by John Abbott about 4 years ago

  • Status changed from New to In Progress
  • % Done changed from 0 to 10

The following works:

use R ::= QQ[x,y,z];
I := IdealOfProjectivePoints(R, mat([[1,0,0]]));
MinGens(I);
J := IdealOfProjectivePoints(R, mat([[1,0,0],[0,1,0]]));
MinGens(J);

#4 Updated by Anna Maria Bigatti about 4 years ago

  • Category changed from Safety to Maths Bugs

#5 Updated by Anna Maria Bigatti about 4 years ago

and this doesn't.

/**/ use P ::= QQ[x,y,z];
/**/ K := IdealOfProjectivePoints(P,mat([[0,1,1],[0,0,1]]));
/**/ MinGens(K);
[]

what's going on???

#6 Updated by John Abbott about 4 years ago

#7 Updated by Anna Maria Bigatti about 4 years ago

  • Related to Bug #1420: IdealOfProjectivePoints and MinGens: problem with CoCoA_ASSERT added

#8 Updated by John Abbott about 4 years ago

There are also some other functions which create a GB without having to calculate it, right?
IdealOfPoints, ...

#9 Updated by Anna Maria Bigatti about 4 years ago

  • Status changed from In Progress to Closed
  • Assignee set to Anna Maria Bigatti
  • % Done changed from 10 to 100

IdealOfProjectivePoints computes GB but cannot determin MinGens.
Neccessary to recompute GBasis with Buchbeger algorithm.
Done and working (see #1420).

Improvement: do it with Hilbert driven Buchberger algorithm.

#10 Updated by Anna Maria Bigatti about 4 years ago

  • Related to Feature #1433: HilbertDriven Buchberger Algorithm added

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