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)
 -- .00657806s elapsed
 -- .018757s elapsed
(number Of blocks, 26)
 -- .000219665s elapsed
1
 -- .000174235s elapsed
1
 -- .000174564s elapsed
1
 -- .000162484s elapsed
1
 -- .000145913s elapsed
2
 -- .000184853s elapsed
 2
2
 -- .0338497s elapsed
 2
2
 -- .000219326s elapsed
 2
2 3
 -- .000186473s elapsed
 2
2 3
 -- .000179033s elapsed
 2
2 3
 -- .000182584s elapsed
 2
2
 -- .000177784s elapsed
 2
2
 -- .000142583s elapsed
2
 -- .000141533s elapsed
2
 -- .000167524s elapsed
 2
2
 -- .000164324s elapsed
 2
2
 -- .000181224s elapsed
 2
2 3
 -- .000169233s elapsed
 2
2 3
 -- .000172994s elapsed
 2
2 3
 -- .000218224s elapsed
 2
2
 -- .000200494s elapsed
 2
2
 -- .00579442s elapsed
2
 -- .000169915s elapsed
1
 -- .000171593s elapsed
1
 -- .000208404s elapsed
1
 -- .000198924s 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-ih1poA/macaulay2-1.26.05+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