carpetDet -- compute the determinant of the crucial constant strand of a carpet X(a,b)

Usage:

d = carpetDet(a,b)
Inputs:
- a, an integer, the larger value, i.e a>=b
- b, an integer, the desired clifford index
Outputs:
- d, an integer, the crucial determinant

Description

We compute nonminimal resolution F of the carpet of type (a,b) over a finite prime field, Lift this to a resolution over ZZ, introduce the fine grading, grep the various blocks of the crucial map in the a-th strand, compute their determinants and return their product.

i1 : a=4,b=4

o1 = (4, 4)

o1 : Sequence

i2 : d=carpetDet(a,b)
 -- .00694639s elapsed
 -- .0123481s elapsed
(number Of blocks, 26)
 -- .000297184s elapsed
1
 -- .000143437s elapsed
1
 -- .000131295s elapsed
1
 -- .000128579s elapsed
1
 -- .000143327s elapsed
2
 -- .000142685s elapsed
 2
2
 -- .000154078s elapsed
 2
2
 -- .000160099s elapsed
 2
2 3
 -- .000140462s elapsed
 2
2 3
 -- .00013971s elapsed
 2
2 3
 -- .000138028s elapsed
 2
2
 -- .000132678s elapsed
 2
2
 -- .000120584s elapsed
2
 -- .000122919s elapsed
2
 -- .000134922s elapsed
 2
2
 -- .00012317s elapsed
 2
2
 -- .000140812s elapsed
 2
2 3
 -- .000133859s elapsed
 2
2 3
 -- .000142265s elapsed
 2
2 3
 -- .000130654s elapsed
 2
2
 -- .000132116s elapsed
 2
2
 -- .000117308s elapsed
2
 -- .000119734s elapsed
1
 -- .000126405s elapsed
1
 -- .000127438s elapsed
1
 -- .000133549s elapsed
1

o2 = 3131031158784

i3 : factor d

      32 6
o3 = 2  3

o3 : Expression of class Product

Ways to use carpetDet:

carpetDet(ZZ,ZZ)

For the programmer

The object carpetDet is a method function.

The source of this document is in /build/reproducible-path/macaulay2-1.25.11+ds/M2/Macaulay2/packages/K3Carpets.m2:1335:0.

carpetDet -- compute the determinant of the crucial constant strand of a carpet X(a,b)

Description

See also

Ways to use carpetDet:

For the programmer