1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283
|
# Copyright (c) 1997-2024
# Ewgenij Gawrilow, Michael Joswig, and the polymake team
# Technische Universität Berlin, Germany
# https://polymake.org
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any
# later version: http://www.gnu.org/licenses/gpl.txt.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#-------------------------------------------------------------------------------
object PolyhedralComplex {
file_suffix pcom
# overrides of derived [[PolyhedralFan]] properties;
# similar to overrides for [[Polytope]] objects derived from [[Cone]]
# @category Input property
# Points in homogeneous coordinates from which the polytopes are formed. May be redundant.
# All vectors in the input must be non-zero. You also need to provide [[INPUT_POLYTOPES]] to define a complex completely.
# Input section only. Ask for [[VERTICES]] if you want a list of non-redundant points.
# @example To obtain a complex consisting of two triangles we can do this (note that,
# contrary to a [[polytope::Polytope|polytope]], this complex is not convex):
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,3,-1],[1,0,1]],INPUT_POLYTOPES=>[[0,1,3],[1,2,3]]);
property POINTS = override INPUT_RAYS;
# @category Geometry
# Number of [[POINTS]].
# @example In the plane, glueing two triangles together along one side gives us a complex with four vertices;
# nevertheless we can specify these two triangles using six points with redundancies:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,0,1],[1,1,0],[2,0,2],[1,1,1]],INPUT_POLYTOPES=>[[0,1,2],[3,4,5]]);
# > print $c->N_VERTICES;
# | 4
# > print $c->N_POINTS;
# | 6
property N_POINTS = override N_INPUT_RAYS;
# @category Visualization
# Unique names assigned to the [[POINTS]]. Similar to [[VERTEX_LABELS]] for [[VERTICES]].
property POINT_LABELS = override INPUT_RAY_LABELS;
# @category Geometry
# Vertices from which the polytopes are formed. Non-redundant. Co-exists with [[LINEALITY_SPACE]].
property VERTICES = override RAYS;
# @category Geometry
# Number of [[VERTICES]].
property N_VERTICES = override N_RAYS;
# @category Visualization
# Unique names assigned to the [[VERTICES]].
# If specified, they are shown by visualization tools instead of vertex indices.
# For a polyhedral complex built from scratch, you should create this property by yourself,
# either manually in a text editor, or with a client program.
property VERTEX_LABELS = override RAY_LABELS;
# @category Geometry
# # The possible linear span normals of all maximal polytopes.
# Empty if [[PURE]] and [[FULL_DIM]], i.e. each maximal polytope has the same dimension as the ambient space.
# @example In the plane, when we construct a polyhedral complex with a 2-dimensional and two 1-dimensional maximal polytopes
# only the latter two will have a linear span with a normal in this ambient space:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,0,1],[1,-1,0],[1,-1,-1]],INPUT_POLYTOPES=>[[0,1,2],[0,3],[0,4]]);
# > print $c->AFFINE_HULL;
# | 0 0 1
# | 0 -1 1
property AFFINE_HULL = override LINEAR_SPAN_NORMALS;
# @category Input property
# Maybe redundant list of not necessarily maximal polytopes. Indices refer to [[POINTS]].
# Each polytope must list all vertices of [[POINTS]] it contains.
# The polytopes are allowed to contain lineality.
# An empty complex does not have any polytopes.
# Input section only. Ask for [[MAXIMAL_POLYTOPES]] if you want to know the maximal polytopes (indexed by [[VERTICES]]).
# @example We can define a polyhderal complex consisting of two distinct triangles with the following (note that additionally stating
# one side of one of these triangles does not affect our resulting complex):
# > $c = new PolyhedralComplex(POINTS=>[[1,1,0],[1,1,1],[1,0,1],[1,-1,0],[1,-1,-1],[1,0,-1]],INPUT_POLYTOPES=>[[0,1,2],[3,4,5],[0,1]]);
# print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {3 4 5}
property INPUT_POLYTOPES = override INPUT_CONES;
# @category Combinatorics
# Non redundant list of maximal polytopes. Indices refer to [[VERTICES]].
# An empty complex does not have any polytopes.
# @example After creating a complex via the [[INPUT_POLYTOPES]] property, we can display all maximal polytopes rising from
# that definition:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,1,1],[1,0,1]],INPUT_POLYTOPES=>[[0,1,2],[0,3],[2]]);
# > print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {0 3}
property MAXIMAL_POLYTOPES = override MAXIMAL_CONES;
# @category Combinatorics
property MAXIMAL_POLYTOPES_THRU_VERTICES = override MAXIMAL_CONES_THRU_RAYS;
# @category Combinatorics
# Number of [[MAXIMAL_POLYTOPES]].
# @example The number of maximal polytopes of a [[planar_net|planar net]] of a polytope is the number of facets of that polytope;
# here we see this for the dodecahedron:
# > $c = planar_net(dodecahedron());
# > print $c->N_MAXIMAL_POLYTOPES;
# | 12
property N_MAXIMAL_POLYTOPES = override N_MAXIMAL_CONES;
# @category Combinatorics
# Array of incidence matrices of all [[MAXIMAL_POLYTOPES|maximal polytopes]].
# @example [prefer cdd] Here we construct a polyhedral complex made of two triangles which share a side; this fact can afterwards be read from
# this property:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,1,1],[1,0,1]],INPUT_POLYTOPES=>[[0,1,2],[1,2,3]]);
# > print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {1 2 3}
# > print $c->MAXIMAL_POLYTOPES_INCIDENCES;
# | <{1 2}
# | {0 2}
# | {0 1}
# | >
# | <{1 2}
# | {2 3}
# | {1 3}
# | >
property MAXIMAL_POLYTOPES_INCIDENCES = override MAXIMAL_CONES_INCIDENCES;
# @category Combinatorics
# The combinatorial dimensions of the maximal polytopes. The i-th entry refers to the i-th entry of [[MAXIMAL_POLYTOPES]].
# @example When connecting two vertices of a triangle to a vertex distinct from that triangle we receive a polyhedral complex
# with maximal polytopes of dimensions 2, 1 and 1, respectively:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,1,1],[1,0,1]],INPUT_POLYTOPES=>[[0,1,2],[0,3],[2,3]]);
# > print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {0 3}
# | {2 3}
# > print $c->MAXIMAL_POLYTOPES_COMBINATORIAL_DIMS;
# | 2 1 1
property MAXIMAL_POLYTOPES_COMBINATORIAL_DIMS = override MAXIMAL_CONES_COMBINATORIAL_DIMS;
# @category Geometry
# A basis of the normal space for each maximal polytope. This uniquely determines the affine hull of the corresponding maximal polytope.
# Indices refer to [[AFFINE_HULL]].
# Rows correspond to [[MAXIMAL_POLYTOPES]].
# An empty row corresponds to a full-dimensional cone.
# @example In the plane, when we construct a polyhedral complex with a 2-dimensional and two 1-dimensional maximal polytopes
# only the latter will have a linear span with a normal in this ambient space:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,0,1],[1,-1,0],[1,-1,-1]],INPUT_POLYTOPES=>[[0,1,2],[0,3],[0,4]]);
# > print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {0 3}
# | {0 4}
# > print rows_numbered($c->AFFINE_HULL);
# | 0:0 0 1
# | 1:0 -1 1
# > print $c->MAXIMAL_POLYTOPES_AFFINE_HULL_NORMALS;
# | {}
# | {0}
# | {1}
property MAXIMAL_POLYTOPES_AFFINE_HULL_NORMALS = override MAXIMAL_CONES_LINEAR_SPAN_NORMALS;
# @category Geometry
# Tells for each maximal polytope what are its facet normals, thus implying the facets.
# Each row corresponds to a maximal polytope and each column to the row with the same index of [[AFFINE_HULL]].
# A negative number means that the corresponding row of
# [[AFFINE_HULL]] has to be negated.
# @example [prefer cdd] Here we see the facet normals of the maximal polytopes of a complex made of two triangles (note that some
# facet normal appear to be redundant due to usage of homogeneous coordinates and the derivation from PolyhedralFan):
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,1,1],[1,0,1]],INPUT_POLYTOPES=>[[0,1,2],[0,2,3]]);
# > print $c->MAXIMAL_POLYTOPES;
# | {0 1 2}
# | {0 2 3}
# > print rows_numbered($c->FACET_NORMALS);
# | 0:1 -1 0
# | 1:0 1 -1
# | 2:0 0 1
# | 3:1 0 -1
# | 4:0 1 0
# > print $c->MAXIMAL_POLYTOPES_FACETS;
# | 1 1 1 0 0
# | 0 -1 0 1 1
property MAXIMAL_POLYTOPES_FACETS = override MAXIMAL_CONES_FACETS;
# @category Combinatorics
# List of all polytopes of the complex of each dimension. Indices refer to [[VERTICES]].
# @example [prefer cdd] A complex whose only maximal polytope is a triangle also contains 3 line segments and 3 points:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[1,0,1]],INPUT_POLYTOPES=>[[0,1,2]]);
# > print $c->POLYTOPES;
# | <{1}
# | {2}
# | {0}
# | >
# | <{1 2}
# | {0 2}
# | {0 1}
# | >
# | <{0 1 2}
# | >
property POLYTOPES = override CONES;
# @category Combinatorics
property N_POLYTOPES = override N_CONES;
# @category Geometry
# True if each object in [[MAXIMAL_POLYTOPES]] is [[Polytope::BOUNDED|bounded]].
property BOUNDED : Bool;
# @category Geometry
# Indices of vertices that are rays.
# @example We construct a PolyhedralComplex consisting only of one unbounded [[Polytope]] which is the Minkowski sum of an interval and a cone orthogonal to this line. Such a Minkowski sum always has a far vertex:
# > $c = new PolyhedralComplex(POINTS=>[[1,0,0],[1,1,0],[0,0,1]],INPUT_POLYTOPES=>[[0,1,2]]);
# > print rows_numbered($c->VERTICES);
# | 0:1 0 0
# | 1:1 1 0
# | 2:0 0 1
# > print $c->FAR_VERTICES;
# | {2}
property FAR_VERTICES : Set;
# @category Geometry
# Returns the //i//-th facet of the complex as a [[Polytope]].
# @param Int i
# @return Polytope
# warning: might be unbounded
# @example The [[planar_net|planar net]] of the 3-dimensional cross polytope consists only of triangles (and the according
# adjacent lines and vertices); asking for any of its polytopes thus gives us a triangle:
# > $c = planar_net(cross(3));
# > $p = $c->polytope(5);
# > print rows_numbered($p->VERTICES);
# | 0:1 0 0
# | 1:1 0.707106781186547 -1.22474487139159
# | 2:1 -0.707106781186549 -1.22474487139159
user_method polytope($) : MAXIMAL_POLYTOPES {
my $p=new Polytope<Scalar>($_[0]->cone($_[1]));
return $p;
}
# @category Geometry
# Returns the dimension of the ambient space.
# @return Int
# @example The ambient dimension of a point in the line is 1:
# > $c = new PolyhedralComplex(POINTS=>[[1,0]],INPUT_POLYTOPES=>[[0]]);
# > print $c->AMBIENT_DIM;
# | 1
user_method AMBIENT_DIM() : FAN_AMBIENT_DIM {
my ($self)=@_;
return $self->FAN_AMBIENT_DIM-1;
}
# @category Geometry
# Returns the dimension of the linear space spanned by the complex.
# @return Int
# @example The dimension of a point in the line is 0:
# > $c = new PolyhedralComplex(POINTS=>[[1,0]],INPUT_POLYTOPES=>[[0]]);
# > print $c->DIM;
# | 0
user_method DIM {
my ($self)=@_;
if (!defined ($self->lookup("LINEALITY_SPACE | INPUT_LINEALITY | INPUT_RAYS | RAYS | FACET_NORMALS | LINEAR_SPAN_NORMALS"))) {
return $self->COMBINATORIAL_DIM;
}
return $self->FAN_DIM-1;
}
}
# Local Variables:
# mode: perl
# cperl-indent-level:3
# indent-tabs-mode:nil
# End:
|