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Reference documentation for older polymake versions: release 3.4, release 3.3, release 3.2

BigObject DisjointStackyFan<Scalar>

from application fan

This represents a stacky fan built from the orbit of a fan F under a group G that permutes the homogeneous coordinates of F's rays. It is assumed, but currently not checked, that the interior of F does not intersect the interiors of its images.

Type Parameters:

Scalar: numeric data type used for the coordinates, must be an ordered field. Default is Rational.

derived from:

These properties capture information of the object that is concerned with the action of permutation groups.


The HASSE_DIAGRAM of the fan that was used to generate it. Must be of type Sequential because Cone::HASSE_DIAGRAM has that type



The MAXIMAL_CONES of the fan that were used to generate it.



The RAYS of the stacky fan that were used to generate it.



The number of RAYS of the stacky fan that were used to generate it. By the way orbit_fan works, these rays also show up at the beginning of the RAYS matrix.



for higher barycentric subdivisions, store the original RAYS_ACTION.GENERATORS They are stored outside of a GROUP object, because these generators act on the elements of the innermost sets of the VERTEX_LABELS, but not on anything directly in the object itself



From a fan F equipped with a symmetry group G acting on the coordinates, * such that the interior of F does not intersect the interiors of its images,* calculate the faces of F of all dimensions that lie in distinct orbits of G.F The data is organized as an array, one entry for each dimension starting with 1; each entry is a Set, one for each orbit of that dimension; each entry is a Set<Set<Int» of faces Set<Int> in that orbit that lie in F



Counts the number of STACKY_FACES



Vertex labels as an array of Set<Set<Int». This is more efficient than the String type used in topaz::SimplicialComplex


  • documentation/latest/fan/disjointstackyfan.txt
  • Last modified: 2022/01/14 11:15
  • (external edit)