Feature #780
GroebnerFan/ExternalLib-GFan: improve package
Description
First prototype is working.
Investigate and improve it, and implement it in cocoalib.
Related issues
History
#1 Updated by Anna Maria Bigatti over 8 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 20
In the package there are lots of operations on integers and those would surely be faster in cocoalib (at some point).
But I did make some improvements:
- the function "matrix" in cocoa-5, using the function SetRow
(and that's good in general ;-)
- a minor improvement in MarkedPolynomialsToInequalities
(just to touch fewer INTs)
- in GroebnerBasisFlip
: ideal(apply(f, gens(I)))
instead of ideal(apply(f, GBasis(I)))
(the ideals are equal, and gens are generally simpler and fewer)
With these changes I get the answer in 68s instad of 82s.
(That's a decent start)
/**/ Use R ::= QQ[a,b,c]; /**/ I := ideal(a^5+b^3+c^2-1, b^2+a^2+c-1, c^3+a^6+b^5-1); /**/ l:=AllReducedGroebnerBases(I); len(l);
What I find strange is that I get these two cumulative times:
GFanGetFacets: 21.999sec
GFanRelativeInteriorPoint: 4.599sec
and these alone take much longer than the complete computation in gfan.
Can the overhead be so bad?
#2 Updated by Anna Maria Bigatti about 8 years ago
- Target version changed from CoCoALib-0.99540 Feb 2016 to CoCoALib-0.99542 spring 2016
#3 Updated by Anna Maria Bigatti about 8 years ago
- Target version changed from CoCoALib-0.99542 spring 2016 to CoCoALib-1.0
#4 Updated by Anna Maria Bigatti over 7 years ago
- Related to Feature #903: New function CallOnGroebnerFanIdeals: call function on GFan ideals added
#5 Updated by Anna Maria Bigatti almost 7 years ago
- Related to Slug #1049: GroebnerFan: slow examples added
#6 Updated by Anna Maria Bigatti almost 7 years ago
Abbott found this gives error (#1049)
GroebnerFanIdeals(ideal(x*y,y^3+x,y^3));
I investigated: it's an error in
ReducedGBasis
(argh)#7 Updated by Anna Maria Bigatti almost 7 years ago
- Subject changed from ExternalLib-GFan: improve package to GroebnerFan/ExternalLib-GFan: improve package