# Object -- select the combinatorial object which the input should be interpreted as

## Synopsis

• Usage:
slackMatrix(V, Object => "matroid")
slackIdeal(V, Object => "abstractPolytope")
symbolicSlackMatrix(V, Object => "polytope")
cycleIdeal(V, Object => "matroid")
graphicIdeal(V, Object => "abstractPolytope")
getFacetBases(V, Object => "cone")
slackFromPlucker(V, Object => "polytope")
symbolicSlackOfPlucker(V, Object => "matroid")
grassmannSectionIdeal(V, Object => "cone")
findFlag(V, Object => "matroid")
containsFlag(fl, V, Object => "matroid")
reducedSlackMatrix(V, Object => "polytope")

## Description

The default value is polytope.

## Functions with optional argument named Object :

• slackMatrix -- computes the slack matrix of a given realization
• slackIdeal -- computes the slack ideal
• symbolicSlackMatrix -- computes the symbolic slack matrix
• cycleIdeal -- constructs the cycle ideal of a realization
• graphicIdeal -- creates the toric ideal of the non-incidence graph of a polytope
• getFacetBases -- given a slack matrix or a list of vertices of d-polytope or a rank d+1 matroid, or (d+1)-cone generators, creates a sorted list of vertices (empty if a matrix is given as input) in the order corresponding to B, and B the list of d spanning elements for each facet
• slackFromPlucker -- given a slack matrix or a list of vertices of d-polytope or a rank d+1 matroid, or (d+1)-cone generators, it fills the corresponding slack matrix with Plucker coordinates
• symbolicSlackOfPlucker -- given the number of polytope vertices, cone generators, or matroid vectors, or a set of polytope vertices, cone generators, or matroid vectors, or a slack matrix and a set of set of hyperplane spanning set indices, it fills the slack matrix with Plucker variables
• grassmannSectionIdeal -- given a slack matrix of a polytope, a cone or a matroid, or a set of polytope vertices, cone generators, or matroid vectors, and a set of set of hyperplane spanning set indices, it computes the Grassmannian section ideal corresponding to choice B of the object with slack matrix S
• findFlag -- computes a list of facet labels that make up a flag in a polytope
• containsFlag -- establishes whether or not a list of facet labels contains a flag in a polytope or matroid
• reducedSlackMatrix -- a reduced slack matrix of a polytope

## For the programmer

The object Object is .