net.sf.oriented.omi

Interface FaceLattice

All Superinterfaces:

Verify

All Known Subinterfaces:

OMasFaceLattice

public interface FaceLattice
extends Verify

The face lattice corresponding to an oriented matroid. Each face (except for the top() face), is labelled with a covector from the oriented matroid. The lattice partial order is defined by SignedSet.isRestrictionOf(SignedSet).

Author:

jeremycarroll

Method Summary

Methods

Modifier and Type	Method and Description
Face	bottom() The bottom face of the lattice, labelled with the empty signed set.
Face	get(SignedSet covector) The face labeled with the given covector.
Iterator<Face>	iterator() The faces in the lattice.
Face	top() The (artificial) top face of the lattice.
Collection<? extends Face>	withDimension(int d) The grade of the face lattice with faces of a given dimension.
Iterable<Face>	withDimensions(int lower, int upper) An iterable of the grades of the lattice between lower and upper inclusive.

Methods inherited from interface net.sf.oriented.omi.Verify

verify

Method Detail

top

Face top()

The (artificial) top face of the lattice.

Returns:

the top face.

bottom

Face bottom()

The bottom face of the lattice, labelled with the empty signed set.

Returns:

the bottom face.

withDimension

Collection<? extends Face> withDimension(int d)

The grade of the face lattice with faces of a given dimension. The face lattice is graded, meaning that bottom() has dimension -1, and top() has dimension OM.rank(), every other face has dimension between these values, and the face lattice forms layers of each dimension.

Parameters:

d -

Returns:

the faces with the given dimension.

iterator

Iterator<Face> iterator()

The faces in the lattice.

Returns:

An iterator over all the faces.

withDimensions

Iterable<Face> withDimensions(int lower,
                            int upper)

An iterable of the grades of the lattice between lower and upper inclusive.

Parameters:

lower - The inclusive lower bound of the dimension of the returned faces.

upper - The inclusive upper bound of the dimension of the returned faces.

Returns:

An iterable over all the faces with given dimensions.

get

Face get(SignedSet covector)

The face labeled with the given covector.

Parameters:

covector - The label of the face.

Returns:

The corresponding face or null if the argument is not a covector.