Description
The
r-th Hirzebruch surface is the
Fan in
QQ^2 generated by the cones <e_1,e_2>, <e_1,-e_2>, <-e_1+r*e_2,-e_2> and <-e_1+r*e_2,e_2>.
i1 : F = hirzebruch 3
o1 = F
o1 : Fan
|
i2 : raysF = rays F
o2 = | 1 0 0 -1 |
| 0 -1 1 3 |
2 4
o2 : Matrix ZZ <-- ZZ
|
i3 : apply(maxCones F, mc -> raysF_mc)
o3 = {| 1 0 |, | 0 -1 |, | 1 0 |, | 0 -1 |}
| 0 1 | | 1 3 | | 0 -1 | | -1 3 |
o3 : List
|