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)
 -- .00650941s elapsed
 -- .0122354s elapsed
(number Of blocks, 26)
 -- .000307245s elapsed
1
 -- .000138219s elapsed
1
 -- .000122339s elapsed
1
 -- .000117751s elapsed
1
 -- .000121839s elapsed
2
 -- .000138338s elapsed
 2
2
 -- .000145923s elapsed
 2
2
 -- .00016019s elapsed
 2
2 3
 -- .000142207s elapsed
 2
2 3
 -- .000140081s elapsed
 2
2 3
 -- .000140332s elapsed
 2
2
 -- .000131436s elapsed
 2
2
 -- .000118591s elapsed
2
 -- .000125615s elapsed
2
 -- .000123732s elapsed
 2
2
 -- .000117701s elapsed
 2
2
 -- .00013875s elapsed
 2
2 3
 -- .000129442s elapsed
 2
2 3
 -- .00013946s elapsed
 2
2 3
 -- .000127819s elapsed
 2
2
 -- .000123612s elapsed
 2
2
 -- .000127318s elapsed
2
 -- .000115637s elapsed
1
 -- .000120826s elapsed
1
 -- .000118121s elapsed
1
 -- .000116157s 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/macaulay2-1.26.06+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