PolyhedralSets[PolyhedralCones]
SimplicialDecomposition
returns a simplicial decomposition of a polyhedral cone
Calling Sequence
Parameters
Description
Examples
Compatibility
SimplicialDecomposition(pc)
SimplicialDecomposition(pc,opts)
pc
-
PolyhedralCone
opts
(optional) option which can be polyhedralcones or polyhedralsets with the former as default value
The command SimplicialDecomposition(pc) returns a simplicial decomposition, as a list of polyhedral sets, of the polyhedral cone pc.
The command SimplicialDecomposition(pc,polyhedralsets) returns the same as a SimplicialDecomposition(pc).
The command SimplicialDecomposition(pc,polyhedralcones) returns a simplicial decomposition, as a list of polyhedral cones, of the polyhedral cone pc.
Terminology
A polyhedral cone in dimension d is the solution set of a system of homogeneous linear non-strict inequalities in d variables. Equivalently, this is the conical hull of finitely many vectors with d coordinates. Here, the base field is that of the real numbers.
Suppose that C is the conical hull of k vectors with d coordinates. Then C is given by the matrix V with k columns and d columns, whose columns are the k vectors. The dual cone of C is the polyhedral set in dimension d which is the solution set of the system of homogeneous linear inequalities, whose matrix is the transpose of the matrix V.
The polyhedral cone C in dimension d is called simplicial if it is generated by d linearly independent vectors. A simplicial decomposition of C is a finite set of simplicial cones so that the union of their interiors (in the Euclidean topology) is equal to the interior of C.
Note that a polyhedral cone C, as a polyhedral set, has a single vertex which is the origin. In practice, it is convenient to use the term polyhedral cone for the translation of a polyhedral cone in the formal sense defined above. With this abuse of terminology, a polyhedral cone is given by a point (its apex, or vertex) and a number of vectors (its generating rays, or simply rays).
with⁡PolyhedralSets:with⁡PolyhedralCones:
Define a polyhedral set
ps≔PolyhedralSet⁡1≤x,1≤y;PolyhedralSets:-Plot⁡ps
ps≔{Coordinates:x,yRelations:−y≤−1,−x≤−1
Define a polyhedral cone from the above polyhedral set
pc≔PolyhedralCone⁡ps
pc≔polyhedral cone with vertex 1,1 and rays 0110
Compute its simplicial decomposition as a list of polyhedral cones
SimplicialDecomposition⁡pc
polyhedral cone with vertex 1,1 and rays 0110
Compute its simplicial decomposition as a list of polyhedral sets
SimplicialDecomposition⁡pc,polyhedralsets
{Coordinates:x1,x2Relations:−x2≤−1,−x1≤−1
Define another polyhedral set
ps≔PolyhedralSet⁡−x1−x2−x3≤0,−x1+x2+x3≤0,x1−x2+x3≤0;PolyhedralSets:-Plot⁡ps
ps≔{Coordinates:x1,x2,x3Relations:−x1−x2−x3≤0,−x1+x2+x3≤0,x1−x2+x3≤0
pc≔polyhedral cone with vertex 0,0,0 and rays 11010−101−1
polyhedral cone with vertex 0,0,0 and rays 11010−101−1
{Coordinates:x1,x2,x3Relations:−x1−x2−x3≤0,−x1+x2+x3≤0,x1−x2+x3≤0
ps≔PolyhedralSet⁡0,0,0,1,−1,1,−1,1,1,−1,−1,1,1,1,11;PolyhedralSets:-Plot⁡ps
ps≔{Coordinates:x1,x2,x3Relations:−x2−x3≤0,−x1−x3≤0,x1+5⁢x26−x36≤0,x1+6⁢x25−x35≤0
pc≔polyhedral cone with vertex 0,0,0 and rays 1−11−1−111111111−111
polyhedral cone with vertex 0,0,0 and rays −1−111111−111,polyhedral cone with vertex 0,0,0 and rays 1−11−1−111111
{Coordinates:x1,x2,x3Relations:−x2−x3≤0,−x1−x3≤0,x1+x2≤0,{Coordinates:x1,x2,x3Relations:−x1−x2≤0,x1+5⁢x26−x36≤0,x1+6⁢x25−x35≤0
The PolyhedralSets[PolyhedralCones][SimplicialDecomposition] command was introduced in Maple 2025.
For more information on Maple 2025 changes, see Updates in Maple 2025.
See Also
PolyhedralSets[PolyhedralCones][DualCone]
PolyhedralSets[PolyhedralCones][PolyhedralCone]
PolyhedralSets[PolyhedralCones][Rays]
PolyhedralSets[PolyhedralCones][Vertex]
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