fan(ToricVectorBundle) -- the underlying fan of a toric vector bundle

Synopsis

• Function: fan

• Usage:

  F = fan E

• Inputs:
  • E, an instance of the type ToricVectorBundle
• Outputs:
  • F, an instance of the type Fan

Description

Returns the fan of the underlying toric variety. This is an object of the package Polyhedra. See also Fan.

i1 : E = tangentBundle hirzebruchFan 3

o1 = {dimension of the variety => 2 }
      number of affine charts => 4
      number of rays => 4
      rank of the vector bundle => 2

o1 : ToricVectorBundleKlyachko

i2 : F = fan E

o2 = F

o2 : Fan

i3 : rays F

o3 = | 1 0  0 -1 |
     | 0 -1 1 3  |

              2        4
o3 : Matrix ZZ  <--- ZZ

See also

• Fan -- the class of all fans
• charts -- the number of maximal affine charts
• maxCones(ToricVectorBundle) -- the list of maximal cones of the underlying fan