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eagonNorthcottType -- Computes the Eagon-Northcott type resolution

Description

This function computes the Eagon-Northcott type resolution associated to the matrix Phi defining the scroll and an integer b defining the twist $O_{P(E)}(bR)$. The way the function works is similar to the way the "Eagon-Northcott" function by Greg Smith works.

i1 : R = ZZ/12347[x_0..x_7]

o1 = R

o1 : PolynomialRing
 
i2 : Phi = matrix{{x_0..x_3},{x_4..x_7}}

o2 = | x_0 x_1 x_2 x_3 |
     | x_4 x_5 x_6 x_7 |

             2      4
o2 : Matrix R  <-- R
 
i3 : betti(eagonNorthcottType(Phi,0))

            0 1 2 3
o3 = total: 1 6 8 3
         0: 1 . . .
         1: . 6 8 3

o3 : BettiTally
 
i4 : betti(eagonNorthcottType(Phi,1))

            0 1 2 3
o4 = total: 2 4 4 2
         0: 2 4 . .
         1: . . 4 2

o4 : BettiTally

See also

Ways to use eagonNorthcottType:

  • eagonNorthcottType(Matrix,ZZ)

For the programmer

The object eagonNorthcottType is a method function.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/RelativeCanonicalResolution.m2:662:0.