/usr/include/polymake/polytope/cayley_embedding.h is in libpolymake-dev-common 3.2r2-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | /* Copyright (c) 1997-2018
Ewgenij Gawrilow, Michael Joswig (Technische Universitaet Berlin, Germany)
http://www.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.
--------------------------------------------------------------------------------
*/
#ifndef POLYMAKE_POLYTOPE_CAYLEY_EMBEDDING_H
#define POLYMAKE_POLYTOPE_CAYLEY_EMBEDDING_H
#include "polymake/Matrix.h"
#include "polymake/Array.h"
#include "polymake/Vector.h"
#include "polymake/Set.h"
#include "polymake/linalg.h"
#include "polymake/vector"
#include "polymake/common/labels.h"
namespace polymake { namespace polytope {
namespace {
template<typename Scalar>
Matrix<Scalar> embedding_matrix(const Matrix<Scalar>& V, int i, int m, const Scalar& t)
{
assert(m>=1 && i>=0 && i<m);
Matrix<Scalar> embedding_matrix(V.rows(), m);
embedding_matrix.col(i) = t * ones_vector<Scalar>(V.rows());
return embedding_matrix;
}
} // end anonymous namespace
template<typename Scalar>
perl::Object cayley_embedding(const Array<perl::Object>& p_array,
const Vector<Scalar>& t_vec,
perl::OptionSet options)
{
const int m = p_array.size();
// input sanity checks
if (!m)
throw std::runtime_error("cayley_embedding: empty array given.");
bool any_pointed(false);
for (const perl::Object& p : p_array) {
const bool pointed = p.give("POINTED");
if (pointed) {
any_pointed=true;
break;
}
}
if (!any_pointed)
throw std::runtime_error("cayley_embedding: at least one input polyhedron must be POINTED");
Set<int> dimensions;
std::vector<int> n_vertices(m);
// rays
std::string has_VERTICES;
bool VERTICES_out = true;
Matrix<Scalar> V_out;
// labels
const bool relabel=!options["no_labels"];
// description of resulting object
std::ostringstream odesc;
odesc << "Cayley embedding of ";
for (int i=0; i<m; ++i) {
// vertices
const Matrix<Scalar> V = p_array[i].give_with_property_name("VERTICES | POINTS", has_VERTICES);
n_vertices[i] = V.rows();
dimensions += V.cols();
if (dimensions.size() >= 2)
throw std::runtime_error("cayley_embedding: dimension mismatch between input polytopes 0 and " + std::to_string(i));
// rays
VERTICES_out = VERTICES_out && has_VERTICES=="VERTICES" && far_points(V).empty();
if (!VERTICES_out && relabel)
throw std::runtime_error("cayley_embedding: can't produce VERTEX_LABELS since VERTICES are unknown in argument " + std::to_string(i));
// scaling
const Scalar t{ t_vec.empty() ? Scalar(1) : t_vec[i] };
// output matrix
V_out /= V | embedding_matrix(V, i, m, t);
// name
if (i>0) odesc << ", ";
odesc << p_array[i].name();
}
perl::Object p_out(perl::ObjectType::construct<Scalar>("Polytope"));
odesc << endl;
p_out.set_description() << odesc.str();
p_out.take(VERTICES_out ? Str("VERTICES") : Str("POINTS")) << V_out;
p_out.take(VERTICES_out ? Str("LINEALITY_SPACE") : Str("INPUT_LINEALITY")) << Matrix<Scalar>(0, V_out.cols());
if (relabel) {
std::vector<std::string> labels(accumulate(n_vertices, operations::add()));
int v_ct(0);
for (int i=0; i<m; ++i) {
common::read_labels(p_array[i], "VERTEX_LABELS", non_const(select(labels, sequence(v_ct, n_vertices[i]))));
for (std::vector<std::string>::iterator
l = labels.begin() + v_ct,
l_end = labels.begin() + v_ct + n_vertices[i];
l != l_end; ++l) {
*l += '_';
*l += '0' + i;
}
v_ct += n_vertices[i];
}
p_out.take("VERTEX_LABELS") << labels;
}
return p_out;
}
} } // end namespaces
#endif // POLYMAKE_POLYTOPE_CAYLEY_EMBEDDING_H
// Local Variables:
// mode:C++
// c-basic-offset:3
// indent-tabs-mode:nil
// End:
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