/usr/include/polymake/polytope/schlegel_common.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 | /* 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_SCHLEGEL_COMMON_H
#define POLYMAKE_POLYTOPE_SCHLEGEL_COMMON_H
#include "polymake/GenericMatrix.h"
#include "polymake/GenericVector.h"
namespace polymake { namespace polytope {
/** @retval alpha>=0 : P=FacetPoint+alpha*ViewRay lies on the nearest neighbor facet hyperplane
alpha<0 : no intersection OR FacetPoint violates some of the neighbor facet constraints
*/
template <typename FMatrix, typename FVector, typename VVector, typename E>
E schlegel_nearest_neighbor_crossing (const GenericMatrix<FMatrix,E>& F,
const GenericVector<FVector,E>& FacetPoint,
const GenericVector<VVector,E>& ViewRay
)
{
E alpha(-1);
bool constrained=false;
for (typename Entire< Rows<FMatrix> >::const_iterator nf=entire(rows(F)); !nf.at_end(); ++nf) {
const E Fr=(*nf)*ViewRay;
if (Fr<0) { // intersection on the negative side
const E alpha_here=-((*nf)*FacetPoint)/Fr;
if (!constrained || alpha_here < alpha) {
constrained=true;
alpha=alpha_here;
}
}
}
return alpha;
}
// FacetPoint=Origin implicitly
template <typename FMatrix, typename VVector, typename E>
E schlegel_nearest_neighbor_crossing (const GenericMatrix<FMatrix,E>& F,
const GenericVector<VVector,E>& ViewRay
)
{
E alpha(-1);
bool constrained=false;
for (typename Entire< Rows<FMatrix> >::const_iterator nf=entire(rows(F)); !nf.at_end(); ++nf) {
const E Fr=(*nf)*ViewRay;
if (Fr<0) { // intersection on the negative side
const E alpha_here=-((*nf)[0]/Fr);
if (!constrained || alpha_here < alpha) {
constrained=true;
alpha=alpha_here;
}
}
}
return alpha;
}
} }
#endif // POLYMAKE_POLYTOPE_SCHLEGEL_COMMON_H
// Local Variables:
// mode:C++
// c-basic-offset:3
// indent-tabs-mode:nil
// End:
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