Slug #1337
Updated by Anna Maria Bigatti over 4 years ago
This example is very very slow because a factor of @MinPolyQuot(t,I,t)@ produces an ideal with a very slow GBasis.
<pre>
K ::= ZZ/(101);
use P ::= ZZ/(101)[x,y,z,t];
F1 := x*y*z*t +83*y^3 +73*x^2 -85*z^2 -437*t;
F2 := y^3*z*t +z -t;
F3 := t^4 +z*t^2 -324*z^3 +94*x^2 +76*y;
F4 := x^11*z +26*t^3 +625*y;
I := ideal(F1, F2, F3, F4);
R:=CpuTime(); RGB := ReducedGBasis(I); TimeFrom(R);
R:=CpuTime(); PD := PrimaryDecomposition(I); TimeFrom(R);
</pre>
The primary decomposition in @ZZ/(101)[t,z,y,x]@ takes less than 4s on my (slow) computer.
This is just unlucky! unlucky.
Can we do something clever about this?
<pre>
K ::= ZZ/(101);
use P ::= ZZ/(101)[x,y,z,t];
F1 := x*y*z*t +83*y^3 +73*x^2 -85*z^2 -437*t;
F2 := y^3*z*t +z -t;
F3 := t^4 +z*t^2 -324*z^3 +94*x^2 +76*y;
F4 := x^11*z +26*t^3 +625*y;
I := ideal(F1, F2, F3, F4);
R:=CpuTime(); RGB := ReducedGBasis(I); TimeFrom(R);
R:=CpuTime(); PD := PrimaryDecomposition(I); TimeFrom(R);
</pre>
The primary decomposition in @ZZ/(101)[t,z,y,x]@ takes less than 4s on my (slow) computer.
This is just unlucky! unlucky.
Can we do something clever about this?