divisor(..., IsGraded => ...) -- optional argument in the divisor constructor to specify that a module $O(D)$ is graded

Synopsis

Usage:
D = divisor(Module, IsGraded => b)
Inputs:
- b, a Boolean value, used to specify whether we view a module as graded
- M, a module, a module to be isomorphic to O(D)
Outputs:
- D, an object of class WeilDivisor

Description

Construct a divisor D such that O(D) is isomorphic to M. If IsGraded is set to true, treat M as a graded module and hence the construction will function properly on a projective variety. Default value is false.

i1 : R = QQ[x,y,z];

i2 : D = divisor(R^{2}, IsGraded=>true)

o2 = 2*Div(x)

o2 : WeilDivisor on R

i3 : D = divisor(R^{-3}, IsGraded=>true)

o3 = -3*Div(x)

o3 : WeilDivisor on R

i4 : D = divisor(R^{2}, IsGraded=>false)

o4 = 0, the zero divisor

o4 : WeilDivisor on R

Further information

Default value: false
Function: divisor -- constructor for (Weil/Q/R)-divisors
Option name: IsGraded -- an option used by numerous functions which tells it to treat the divisors as if we were working on the Proj of the ambient ring.

divisor(..., IsGraded => ...) -- optional argument in the divisor constructor to specify that a module $O(D)$ is graded

Synopsis

Description

Further information

See also