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)
 -- .0115382s elapsed
 -- .0134211s elapsed
(number Of blocks, 26)
 -- .000260832s elapsed
1
 -- .000228353s elapsed
1
 -- .000238574s elapsed
1
 -- .000173261s elapsed
1
 -- .000156891s elapsed
2
 -- .000163061s elapsed
 2
2
 -- .00018065s elapsed
 2
2
 -- .000207382s elapsed
 2
2 3
 -- .000177731s elapsed
 2
2 3
 -- .000210942s elapsed
 2
2 3
 -- .000176632s elapsed
 2
2
 -- .000158851s elapsed
 2
2
 -- .000191712s elapsed
2
 -- .000140572s elapsed
2
 -- .000193173s elapsed
 2
2
 -- .000172151s elapsed
 2
2
 -- .000196731s elapsed
 2
2 3
 -- .000185242s elapsed
 2
2 3
 -- .000213632s elapsed
 2
2 3
 -- .000248302s elapsed
 2
2
 -- .000156061s elapsed
 2
2
 -- .000214422s elapsed
2
 -- .00014373s elapsed
1
 -- .000264282s elapsed
1
 -- .000187261s elapsed
1
 -- .000171742s 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-BDMbwf/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