next | previous | forward | backward | up | top | index | toc | Macaulay2 web site
NormalToricVarieties :: vector(ToricDivisor)

vector(ToricDivisor) -- make the vector of coefficients

Synopsis

Description

This method returns the vector whose i-th entry is the coefficient of i-th torus-invariant prime divisor. The indexing of the torus-invariant prime divisors is inherited from the indexing of the rays in the associated fan. This vector can be viewed as an element of the group of torus-invariant Weil divisors.
i1 : PP2 = projectiveSpace 2;
i2 : D = 2*PP2_0 - 7*PP2_1 + 3*PP2_2    

o2 = 2*D  - 7*D  + 3*D
        0      1      2

o2 : ToricDivisor on PP2
i3 : vector D

o3 = | 2  |
     | -7 |
     | 3  |

       3
o3 : ZZ
i4 : wDiv PP2

       3
o4 = ZZ

o4 : ZZ-module, free
i5 : FF7 = hirzebruchSurface 7;
i6 : E = FF7_0-5*FF7_3

o6 = D  - 5*D
      0      3

o6 : ToricDivisor on FF7
i7 : vector E

o7 = | 1  |
     | 0  |
     | 0  |
     | -5 |

       4
o7 : ZZ
i8 : wDiv FF7

       4
o8 = ZZ

o8 : ZZ-module, free

See also