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)
 -- .00668265s elapsed
 -- .012087s elapsed
(number Of blocks, 26)
 -- .000223629s elapsed
1
 -- .00016511s elapsed
1
 -- .00013133s elapsed
1
 -- .00013297s elapsed
1
 -- .000130791s elapsed
2
 -- .000137211s elapsed
 2
2
 -- .00014073s elapsed
 2
2
 -- .00017261s elapsed
 2
2 3
 -- .000146981s elapsed
 2
2 3
 -- .000141711s elapsed
 2
2 3
 -- .000150069s elapsed
 2
2
 -- .00014433s elapsed
 2
2
 -- .00013651s elapsed
2
 -- .0001337s elapsed
2
 -- .00015294s elapsed
 2
2
 -- .000151871s elapsed
 2
2
 -- .00013751s elapsed
 2
2 3
 -- .000145292s elapsed
 2
2 3
 -- .000156091s elapsed
 2
2 3
 -- .00014431s elapsed
 2
2
 -- .000136831s elapsed
 2
2
 -- .000126861s elapsed
2
 -- .0001296s elapsed
1
 -- .00014674s elapsed
1
 -- .0001324s elapsed
1
 -- .0001495s 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/macaulay2-71Dnnx/macaulay2-1.26.06+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