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Design #455

Which sets of generators in an ideal?

Added by Anna Maria Bigatti about 10 years ago. Updated almost 10 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
Various
Target version:
CoCoALib-1.0
Start date:
03 Mar 2014
Due date:
% Done:

0%

Estimated time:
16.00 h
Spent time:
0.75 h

Description

now we have
myGens
myTidyGens
but in SparsePolyRing we would also need
myGBasis (currently stored in myTidyGens)
myMinGens
myJanetBasis

Related issues

Related to CoCoA-5 - Feature #216: Janet Bases: port function into CoCoA-5In Progress2012-08-02

Related to CoCoALib - Feature #215: Janet Bases: check and include code in CoCoALib (first prototype)Closed2012-08-02

Related to CoCoA-5 - Bug #446: intersection fails with zero idealClosed2014-02-20

Related to CoCoALib - Feature #366: function (CoCoALib) for minimal generators (like old Minimalize)Closed2013-06-11

Related to CoCoALib - Feature #399: add myHilbertSeries member field to ideal and (sub)moduleNew2013-08-02

Related to CoCoALib - Bug #130: Design problem in idealsNew2012-04-15

Related to CoCoALib - Feature #400: add myJBMill member field to idealNew2013-08-02

Related to CoCoALib - Feature #665: Integrate Janet/Pommaret basis codeIn Progress2015-02-11

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

History

#1 Updated by Anna Maria Bigatti about 10 years ago

  • Category set to Various
  • Target version set to CoCoALib-0.99534 Seoul14

from issue Bug #446: intersection fails with zero ideal
John Abbott wrote

What I tried to suggest yesterday, is that an ideal could contain two lists of generators: one is the list the user supplied, the other is a "cleaned list" e.g. without zero values, maybe without duplicates, maybe made monic, perhaps put into a good order, etc. I can see one problem: which list should be used when printing the ideal? Presumably the original user-supplied list should be returned by the mem fn myGens (or whatever it is called). Mmmm, it could be confusing to have two lists... Unless the "cleaned list" is used only when calling ideal operations...???

In fact we already have suche a field: it is called myTidyGens.
So far we have used it for an optimal set of generators: i.e. GBasis, (and a minimal set for ideals in ZZ?)
Even though it would make sense to rename it, I fear it might break some code if we do it now.

#2 Updated by Anna Maria Bigatti about 10 years ago

I think we should have myMinGens in every ideal: a "minimal set of generators" is quite a general concept.
We should then specify in which cases that has "minimal" length or not.
(as for for PIDs and poly homog ideals)

Now we have "myTidyGens", but that has different meanings depending on the ring. Now I think that's probably not a good idea: in polynomial rings we need so many more....

#3 Updated by Anna Maria Bigatti almost 10 years ago

  • Estimated time set to 16.00 h

A similar problem is storing HilbertFunction and resolution in the ideal/module

#4 Updated by John Abbott almost 10 years ago

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

#5 Updated by John Abbott almost 8 years ago

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