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lammps/src/MANIFOLD/manifold_torus.cpp
2022-10-24 11:08:26 -04:00

55 lines
1.5 KiB
C++

// clang-format off
/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, Sandia National Laboratories
LAMMPS development team: developers@lammps.org
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
----------------------------------------------------------------------- */
#include <cmath>
#include "manifold_torus.h"
#include "error.h"
using namespace LAMMPS_NS;
using namespace user_manifold;
manifold_torus::manifold_torus( LAMMPS *lmp, int /*argc*/, char **/*argv*/ ) : manifold(lmp)
{}
double manifold_torus::g( const double *x )
{
double R = params[0];
double r = params[1];
if (R < r) {
error->all(FLERR,"Large radius < small radius!");
}
double rad = sqrt(x[0]*x[0] + x[1]*x[1]);
double c = R - rad;
return c*c + x[2]*x[2] - r*r;
}
void manifold_torus::n( const double *x, double *n )
{
double R = params[0];
double r = params[1];
if (R < r) {
error->all(FLERR,"Large radius < small radius!");
}
double rad = sqrt(x[0]*x[0] + x[1]*x[1]);
double c = R - rad;
double fac = c / rad;
n[0] = -2.0 * fac * x[0];
n[1] = -2.0 * fac * x[1];
n[2] = 2.0 * x[2];
}