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Slug #1638

MinSubsetOfGens sometimes very slow

Added by John Abbott over 2 years ago. Updated over 2 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
enhancing/improving
Target version:
CoCoA-5.4.2
Start date:
06 Dec 2021
Due date:
% Done:

0%

Estimated time:
Spent time:
0.20 h

Description

I have just tried MinSubsetOfGens, and was surprised how slow it was on a small example.

use QQ[x,y,z];
L := [5*x*z^3 -3*z^4 +4*z -1,  -4*x^3*z +4*y*z^3 -2*y^3 -x*z];
RGB := ReducedGBasis(ideal(L)); --> contains 8 elems
I := ideal(RGB);
MinSubsetOfGens(I); -- 1000+seconds

Related issues

Related to CoCoA-5 - Bug #1640: MinSubsetOfGens does not find min subsetClosed2021-12-08

History

#1 Updated by John Abbott over 2 years ago

There are only 256 subsets to try; and some can be quickly eliminated.
I saw the source, and understand that it is not designed to be fast... but I had not expected it to be so slow!

Maybe some simpler "slug" examples will surface.

#2 Updated by John Abbott over 2 years ago

  • Related to Bug #1640: MinSubsetOfGens does not find min subset added

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