Page MenuHomec4science
Files F75907814

manifold_gaussian_bump.h
No OneTemporary
Actions

File Metadata

Created
Mon, Aug 5, 01:24

manifold_gaussian_bump.h
View Options

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
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.
-----------------------------------------------------------------------
This file is a part of the USER-MANIFOLD package.
This package allows LAMMPS to perform MD simulations of particles
constrained on a manifold (i.e., a 2D subspace of the 3D simulation
box). It achieves this using the RATTLE constraint algorithm applied
to single-particle constraint functions g(xi,yi,zi) = 0 and their
derivative (i.e. the normal of the manifold) n = grad(g).
It is very easy to add your own manifolds to the current zoo
(we now have sphere, a dendritic spine approximation, a 2D plane (for
testing purposes) and a wave-y plane.
See the README file for more info.
Stefan Paquay, spaquay@brandeis.edu
Brandeis University, Waltham, MA, USA.
This package was mainly developed at
Applied Physics/Theory of Polymers and Soft Matter,
Eindhoven University of Technology (TU/e), The Netherlands
Thanks to Remy Kusters at TU/e for testing.
This software is distributed under the GNU General Public License.
------------------------------------------------------------------------- */
#ifndef LMP_MANIFOLD_GAUSSIAN_BUMP_H
#define LMP_MANIFOLD_GAUSSIAN_BUMP_H
#include "manifold.h"
namespace LAMMPS_NS {
namespace user_manifold {
// A Gaussian bump with a smoothed decay to flat 2D.
class manifold_gaussian_bump : public manifold {
public:
enum { NPARAMS = 4 };
manifold_gaussian_bump(class LAMMPS*, int, char **);
virtual ~manifold_gaussian_bump();
virtual double g( const double * );
virtual void n( const double *, double * );
// Variant of g that computes n at the same time.
virtual double g_and_n( const double *x, double *nn );
static const char* type(){ return "gaussian_bump"; }
virtual const char *id() { return type(); }
virtual int nparams(){ return NPARAMS; }
virtual void post_param_init();
private:
// Some private constants:
double AA, ll, ll2, f_at_rc, fp_at_rc;
double rc1, rc2, rc12, rc22, dr, inv_dr;
// Stuff for the look-up table:
double lut_x0, lut_x1;
int lut_Nbins;
double lut_dx;
double *lut_z;
double *lut_zp;
double gaussian_bump ( double ) const;
double gaussian_bump_x2 ( double ) const;
double gaussian_bump_der( double ) const;
void make_lut();
double lut_get_z ( double rr ) const;
double lut_get_zp( double rr ) const;
void lut_get_z_and_zp( double rr, double &zz, double &zzp ) const;
void test_lut();
double taper( double );
double taper_der( double );
};
}
}
#endif // LMP_MANIFOLD_GAUSSIAN_BUMP_H

Event Timeline

c4science · Help