These properties and pseudo-targets are known to polymake
when the default set of rules poly.rules is used.
Basic sections |
|
| matrix |
Points such that the polyhedron is their convex hull.
Redundancies are allowed.
Vector (x0 x1 .. xd) represents a point in (d+1)-space (homogeneous coordinates.)
Affine points are identified by x0 > 0.
Points with x0 = 0 can be interpreted as rays.
polymake automatically normalizes each coordinate vector, dividing them by the first non-zero element.
The clients and rule subroutines can always assume that x0 is either 0 or 1.
|
| matrix | Vertices of the polyhedron. No redundancies are allowed. The coordinates are normalized the same way as POINTS. |
| matrix | Inequalities that describe half-spaces such that the polyhedron is their intersection. Redundancies are allowed. Dual to POINTS. A vector (A0 A1 .. Ad) defines the (closed affine) half-space of points (1,x1,..,xd) such that A0 + A1 x1 + .. + Ad xd >= 0. |
| matrix | Facets of the polyhedron. Dual to VERTICES. |
| matrix | Equations that hold for all points of the polyhedron. A vector (A0 A1 .. Ad) describes the hyperplane of all points (1,x1,..,xd) such that A0 + A1 x1 + .. + Ad xd = 0. |
| matrix | Dual basis of the affine hull of the polyhedron. |
| vector | Some point belonging to the polyhedron. |
| cardinal | Dimension of the affine hull of the polyhedron = dimension of the polyhedron. |
| cardinal | Dimension of the space where the polyhedron lives in. |
| boolean | true if the polyhedron is not empty. |
| boolean | true if the polyhedron does not contain an affine line. |
| boolean | true if DIM == AMBIENT_DIM |
| set | Indices of vertices that are rays. |
| boolean | true if the polyhedron is a bounded polytope. |
| boolean | true if (1,0,0,..) is a relative interior point. Polar to BOUNDED. |
| boolean | true if all vertices of the polyhedron have non-negative coordinates, that is, it lies entirely in the positive orthant. |
| cardinal | Number of points. |
| vector | The center of gravity of the vertices of a bounded polytope. |
| matrix | Contains the vector configuration for which a zonotope can be built. |
| matrix | Some invertible linear transformation that can be used to get back a previous coordinate repersentation of the polytope. It operates from the right on point row vectors (e.g. in sections like POINTS, VERTICES, REL_INT_POINT); its inverse operates from the left on hyperplane column vectors. |
| vector of words |
Unique names assigned to the vertices.
If specified, they are shown by visualization tools instead of vertex indices.
For a polytope build from scratch, you should create this section by yourself,
either manually in a text editor, or with a client program. If you build a polytope with a construction client
taking some other input polytope(s), you can create the labels automatically if you
call the client with a
-relabel option. The exact format of the labels is dependent on the
construction, and is described by the corresponding client.
|
| vector of words | Unique names assigned to the facets, analogous to VERTEX_LABELS. |
| matrix | Matrix of a projective transformation mapping the whole polytope into one of its facets (specified by SCHLEGEL_PARAMS). The points belonging to this facet stay fixed. |
| matrix | Coordinates of the Gale transform. |
| matrix | A weighted inner point depending on the outer angle called Steiner point for all faces of dimensions 2 to d. |
Combinatorics |
|
|
DIM
cardinal
|
Dimension of a minimal embedding space deduced from the combinatorial structure. |
| cardinal | Number of vertices. |
| cardinal | Number of facets. |
| cardinal | Number of pairs of incident vertices and facets. |
| incidence matrix | Vertex-facet incidence matrix, with rows corresponding to facets and columns to vertices. Vertices and facets are numbered from 0 to N_VERTICES-1 rsp. N_FACETS-1, according to their order in VERTICES rsp. FACETS. |
| transposed VERTICES_IN_FACETS | |
| face lattice |
The face lattice of the polytope organized as a directed graph.
Each node corresponds to some proper face of the polytope. It is represented
as the list of vertices comprising the face. The arcs are directed with increasing dimension.
|
| pseudo |
A pseudo-target causing the face lattice to be printed on the standard output.
Unlike HASSE_DIAGRAM, the computed face lattice is just dumped out, but not stored
in the data file. Thus you can apply it to polytopes with rather many faces without the risk of
exhausting your disk space.
The output is ordered by dimension. Each row starts with [ -k : fd-k ],
where k is the co-dimension, and fd-k the number of faces
(as in F_VECTOR.) The faces are represented as lists of vertex indices. They appear
lexicographically sorted.
|
| pseudo | Dual to FACE_LATTICE. The dual faces are represented as lists of facet indices. |
| vector of cardinals | Number of incident facets for each vertex. |
| vector of cardinals | Number of incident vertices for each facet. |
| list of sets | Vertex-edge graph. Each line corresponds to a vertex and contains indices of adjacent vertices. |
| list of sets | Facet-ridge graph. Dual to GRAPH. |
| cardinal | Number of edges. |
| cardinal | Number of ridges. |
| vector of cardinals | Degrees of vertices in the GRAPH. |
| vector of cardinals | Degrees of facets in the DUAL_GRAPH. |
| cardinal | Graph theoretical diameter of GRAPH. |
| cardinal | Graph theoretical diameter of DUAL_GRAPH. |
| boolean | true if GRAPH does not contain a triangle. |
| boolean | true if DUAL_GRAPH does not contain a triangle. |
| cardinal | Let M be the vertex-facet incidence matrix, then the Altshulter determinant is defined as max{det(M∗MT), det(MT∗M)}. |
| vector of cardinals | fk is the number of k-faces. |
| matrix of cardinals | fik is the number of incident pairs of i-faces and k-faces; the main diagonal contains the F_VECTOR. |
| vector of cardinals | Simplicial h-vector. Defined for simplicial polytopes and also for their duals. |
| boolean | All intermediate polytopes (with respect to the given insertion order) in the beneath-and-beyond algorithm are simplicial. We have the implications: VERTICES in general position => ESSENTIALLY_GENERIC => SIMPLICIAL |
| boolean | true if the polytope is simplicial. |
| boolean | true if the polytope is simple. Dual to SIMPLICIAL. |
| boolean | true if the GRAPH of the polytope is bipartite. |
| boolean | true if the DUAL_GRAPH of the polytope is bipartite. Dual to EVEN. |
| cardinal | Node connectivity of the GRAPH of the polytope, that is, the minimal number of nodes to be removed from the graph such that the result is disconnected. |
| cardinal | Node connectivity of the DUAL_GRAPH of the polytope. Dual to CONNECTIVITY |
| cardinal | Maximal dimension in which all faces are simplices. |
| Maximal dimension in which all dual faces are simplices. | |
| cardinal | Maximal dimension in which all faces are simple polytopes. |
| boolean | true if all facets are cubes. |
| cardinal | Maximal dimension in which all facets are cubes. |
| boolean | dual to CUBICAL. |
| cardinal | dual to CUBICALITY. |
| boolean | true if the polytope is neighborly. |
| cardinal | Maximal dimension in which all facets are neighborly. |
| boolean | dual to NEIGHBORLY. |
| cardinal | Maximal dimension in which all facets are balanced. |
Convex hull computationNote that an explicit request for any pseudo-target from this group will overwrite the VERTICES or FACETS sections created formerly, as well as rearrange or delete other sections depending on these (VERTICES_IN_FACETS, GRAPH, etc.) |
|
| incidence matrix | Similar to VERTICES_IN_FACETS, but with columns corresponding to POINTS instead of VERTICES. This section is a byproduct of convex hull computation algorithms. It is discarded as soon as VERTICES_IN_FACETS is computed. |
| incidence matrix | Similar to VERTICES_IN_FACETS, but with rows corresponding to INEQUALITIES instead of FACETS. This section is a byproduct of convex hull computation algorithms. It is discarded as soon as VERTICES_IN_FACETS is computed. |
| pseudo | Use the double description method as implemented in cddlib. It is the default algorithm for computation of facets from points or dually. It operates with arbitrary precision arithmetic (GMP) or floating-point numbers, depending upon which rule set is being used. |
| pseudo | Use the reverse search method, as implemented in lrslib |
| pseudo | Use the sequential (beneath-beyond) convex hull algorithm. It performs well at lower dimensions and produces a triangulation of the polytope as a byproduct. There is no dual (vertex enumeration) implementation of this algorithm. |
| pseudo | Run the porta program, implementing the Fourier-Motzkin elimination method. The essential drawback of this tool is that it employs a limited-precision arithmetic, and therefore can fail on numerically difficult problems. |
Triangulation and volumeEverything in this group is defined for bounded polytopes only. |
|
| scalar | Volume of the polytope. |
| list of sets | Some triangulation of the polytope using only its vertices. Each line contains indices from VERTICES comprising a simplex. |
| list of sets | Similar to TRIANGULATION, but using POINTS. |
| list of powersets | Intersection of TRIANGULATION with polytope boundary. Each line describes the triangulation of the corresponding facet as a list of simplices. |
| vector | For each simplex in TRIANGULATION, contains the sign of determinant of its coordinate matrix, thus telling about its orientation. |
| vector | Similar to TRIANGULATION_SIGNS, but describes TRIANGULATION_INT. |
Visualization |
|
| list of vectors of cardinals | Reordered VERTICES_IN_FACETS for 2-d and 3-d polytopes. Vertices are listed in the order of their appearance when traversing the facet border counterclockwise seen from outside of the polytope. For a 2-d polytope (which is a closed polygon), lists all vertices in the border traversing order. |
| list of vectors of cardinals | Reordered DUAL_GRAPH for 3-d polytopes. The neighbor facets are listed in the order corresponding to VIF_CYCLIC_NORMAL, so that the first two vertices in VIF_CYCLIC_NORMAL make up the ridge to the first neighbor facet and so on. |
| list of vectors of cardinals | Reordered transposed VERTICES_IN_FACETS. Dual to VIF_CYCLIC_NORMAL. |
| list of vectors of cardinals | Reordered GRAPH. Dual to NEIGHBOR_FACETS_CYCLIC_NORMAL |
| tuple(cardinal,scalar,vector,vector) | Describes the parameter settings for the Schlegel diagram. The first line contains the index of the projection facet and the zoom factor. The following two coordinate vectors specify a point on the projection facet and an interior point of the polytope (in this order!) The line joining these two points is the view direction in the diagram. |
| matrix | Coordinates in affine 3-space of the vertices which correspond to a 3-dimensional (Schlegel-) projection of a 4-polytope. |
| matrix | Coordinates of points for an affine Gale diagram. |
| pseudo | Generates the Gale diagram of a d-polyhedron with at most d+4 vertices
as a PostScript drawing and shows it via gv. You can set up your favorite
PostScript renderer and tune some layout details such as paper format or font size
in the customization file postscript.def.
|
| matrix | Coordinates in affine 2- resp. 3-space of the vertices which correspond to a 2- resp. 3-dimensional (Schlegel-) projection of a 3 resp. 4-polytope. |
| pseudo | Use the connecting line between the Steiner points as a view direction for Schlegel projection |
| word | Name of a package implementing the graph visualization interface. |
| list of sets of cardinal |
Vertices to be visibly set off from the rest. Depending on the graph visualization method, the nodes
corresponding to the selected vertices can be drawn bold, pulled aside in the 3-d embedding, or something else.
Currently there are no rules producing this section; it should be filled in manually when desired.
Please remember the valid syntax: each line must be enclosed in curly braces.
|
| pseudo | Visualization of the GRAPH of a polyhedron. |
| pseudo | Visualization of the DUAL_GRAPH of a polyhedron. |
| pseudo | Visualization of the HASSE_DIAGRAM of a polyhedron as a multi-layer graph. |
| pseudo | Visualization of the DUAL_FACE_LATTICE of a polyhedron as a multi-layer graph. |
| pseudo | Visualization of a 3-dimensional polytope as a solid body. |
| pseudo | Visualization of the dual polytope as a solid body. The polytope must be bounded and centered. |
| pseudo |
Visualization of the TRIANGULATION of a 3-dimensional polytope.
Hint: Use the method 'explode polytope' of javaview for better insight
in the internal structure.
|
| pseudo | Visualization of the TRIANGULATION_BOUNDARY of a 3-dimensional polytope. |
| pseudo | Visualization of the TRIANGULATION_BOUNDARY of a 3-dimensional polytope. |
| pseudo | Visualization of a Schlegel diagram of the 4-dimensional polytope as a wire skeleton. |
| pseudo | Visualization of a Schlegel diagram of TRIANGULATION_BOUNDARY of a 4-dimensional polytope. |
| pseudo | Visualization of a 3-dimensional polytope as a wire skeleton with Steiner points. |
| pseudo | Visualization of a Schlegel diagram of the 3- or 4-dimensional polytope as a wire skeleton with Steiner points. |
| pseudo | Runs geomview - an alternative tool for the visualization of 3- or 4-dimensional polytopes (in the meantime obsolete). |
| pseudo |
Runs javaview program - default tool for the visualization of 3- or 4-dimensional polytopes with known coordinates.
Recently you can also use it for graph visualization. The 3-d spring embedder starts with random node placement, so
you have a chance to get various embeddings when trying it several times.
|
| pseudo | Runs javaview program in the interactive mode, allowing to modify the parameters of the Schlegel projection. |
| JVX file stencil prepared for interactive Schlegel diagram visualization. | |
| pseudo |
Runs graphlet - the default tool for the visualization of graphs of polyhedra.
Hint: use "Layout:Spring Embedder with Constraints" for GRAPH or DUAL_GRAPH;
try also "Layout:DAG" for DIRECTED_GRAPH.
|
| pseudo | Generates a scene file for povray describing a 3- or 4-dimensional polytope as a wire model. |
Optimization |
|
| vector | Linear objective function. |
| vector | Abstract objective function. The i-th element is the value of the objective function at vertex number i. Only defined for bounded polytopes. |
| set | Indices of vertices at which the maximum of the objective function is attained. |
| set | Similar to MAXIMAL_FACE |
| vector | Coordinates of a (possible not unique) vertex at which the maximum of the objective function is attained. |
| vector | Similar to MAXIMAL_VERTEX |
| scalar | Maximum value of the objective function. Negated if linear problem is unbounded. |
| scalar | Similar to MAXIMAL_VALUE |
| list of sets | Subgraph of GRAPH. Consists only of directed arcs along which the value of the objective function increases. |
| vector of cardinals | Number of outgoing arcs for each vertex in DIRECTED_GRAPH. |
| vector of cardinals | Number of incoming arcs for each vertex in DIRECTED_GRAPH. |
| list of RGB | Approximate color encoding of objective function values. For each vertex, the color is chosen by linear interpolation in HSV system between fixed "maximal" and "minimal" colors, with the same ratio as the objective function value has in relation to the global maximum and mininum on the entire polytope. |
| scalar | Expected average path length for a simplex algorithm employing "random edge" pivoting strategy. |
| list of words | You can give a list of variable names here (this amounts to naming the columns of the coordinate vectors for VERTICES). This is of not much use for polymake. But this information will be used by programs which convert polymake format to other formats (such as LP). |
| pseudo |
Visualization of the graph of the polyhedron,
with nodes colored according to the objective function values (VERTEX_COLORS.)
The spring embedder used in javaview mode tries to arrange the nodes so
that their z coordinates approximately correspond to the objective function values.
|
| pseudo | The same as VISUAL_GRAPH, showing the objective function growth direction via arrowed edges. |
| pseudo | The same as VISUAL_COLORED_GRAPH, showing the objective function growth direction via arrowed edges. |
| pseudo | Visualization of a 3-dimensional polytope with superposed DIRECTED_GRAPH. |
| pseudo | Visualization of a Schlegel diagram of a 4-dimensional polytope with superposed DIRECTED_GRAPH. |
Polarization |
|
| vector | Relatively interior point of the polyhedron. |
| vector | Valid strict inequality for all affine points of the polyhedron. |
Oriented matroids |
|
| chirotope | Chirotope corresponding to VERTICES. |
| chirotope | Chirotope corresponding to POINTS. |
| pseudo | Runs the triangulation program from topcom package. |
Integral lattice points |
|
| cardinal | Number of non-negative interior lattice points. |