diff --git a/src/USER-MANIFOLD/fix_nve_manifold_rattle.cpp b/src/USER-MANIFOLD/fix_nve_manifold_rattle.cpp index 4f6b62590d9b71e50d24728417ff225e5953a1d4..67f298d8dfb4e67b8b68c9fe3d6b89142ceab0a1 100644 --- a/src/USER-MANIFOLD/fix_nve_manifold_rattle.cpp +++ b/src/USER-MANIFOLD/fix_nve_manifold_rattle.cpp @@ -115,6 +115,13 @@ FixNVEManifoldRattle::FixNVEManifoldRattle( LAMMPS *lmp, int &narg, char **arg, error->all(FLERR, "Error creating manifold arg arrays"); } + // Check if you have enough args: + if( 6 + nvars > narg ){ + char msg[2048]; + sprintf(msg, "Not enough args for manifold %s, %d expected but got %d\n", + ptr_m->id(), nvars, narg - 6); + error->all(FLERR, msg); + } // Loop over manifold args: for( int i = 0; i < nvars; ++i ){ int len = 0, offset = 0; diff --git a/src/USER-MANIFOLD/manifold_factory.cpp b/src/USER-MANIFOLD/manifold_factory.cpp index 57c6e8305f24af3255946f28f5d2c98dd87f34f7..f98180ddb651540aea8b355b62823f4de25ccb2c 100644 --- a/src/USER-MANIFOLD/manifold_factory.cpp +++ b/src/USER-MANIFOLD/manifold_factory.cpp @@ -37,6 +37,7 @@ #include "manifold_cylinder_dent.h" #include "manifold_dumbbell.h" #include "manifold_ellipsoid.h" +#include "manifold_gaussian_bump.h" #include "manifold_plane.h" #include "manifold_plane_wiggle.h" #include "manifold_sphere.h" @@ -58,12 +59,13 @@ manifold* LAMMPS_NS::user_manifold::create_manifold(const char *mname, make_manifold_if<manifold_cylinder_dent> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_dumbbell> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_ellipsoid> ( &man, mname, lmp, narg, arg ); + make_manifold_if<manifold_gaussian_bump> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_plane> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_plane_wiggle> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_sphere> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_supersphere> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_spine> ( &man, mname, lmp, narg, arg ); - make_manifold_if<manifold_spine_two> ( &man, mname, lmp, narg, arg ); + make_manifold_if<manifold_spine_two> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_thylakoid> ( &man, mname, lmp, narg, arg ); make_manifold_if<manifold_torus> ( &man, mname, lmp, narg, arg ); diff --git a/src/USER-MANIFOLD/manifold_gaussian_bump.cpp b/src/USER-MANIFOLD/manifold_gaussian_bump.cpp new file mode 100644 index 0000000000000000000000000000000000000000..200edd2fb0874bb20a752ed6b8440b885eff198e --- /dev/null +++ b/src/USER-MANIFOLD/manifold_gaussian_bump.cpp @@ -0,0 +1,138 @@ +#include "manifold_gaussian_bump.h" + +using namespace LAMMPS_NS; +using namespace user_manifold; + +// The constraint is z = f(r = sqrt( x^2 + y^2) ) +// f(x) = A*exp( -x^2 / 2 l^2 ) if x < rc1 +// = a + b*x + c*x**2 + d*x**3 if rc1 <= x < rc2 +// = 0 if x >= rc2 +// +double manifold_gaussian_bump::g( const double *x ) +{ + double xf[3]; + xf[0] = x[0]; + xf[1] = x[1]; + xf[2] = 0.0; + + double x2 = dot(xf,xf); + if( x2 < rc12 ){ + return x[2] - gaussian_bump_x2( x2 ); + }else if( x2 < rc22 ){ + double rr = sqrt(x2); + double xi = rr - rc1; + xi *= inv_dr; + double xi2 = x2 * inv_dr*inv_dr; + double xi3 = xi*xi2; + return x[2] - ( aa + bb*xi + cc*xi2 + dd*xi3 ); + + }else{ + return x[2]; + } +} + +void manifold_gaussian_bump::n( const double *x, double *nn ) +{ + double xf[3]; + xf[0] = x[0]; + xf[1] = x[1]; + xf[2] = 0.0; + nn[2] = 1.0; + + double x2 = dot(xf,xf); + + if( x2 < rc12 ){ + double factor = gaussian_bump_x2(x2); + factor /= (ll*ll); + nn[0] = factor * x[0]; + nn[1] = factor * x[1]; + }else if( x2 < rc22 ){ + double rr = sqrt(x2); + double xi = rr - rc1; + xi *= inv_dr; + double xi2 = x2 * inv_dr*inv_dr; + double der = bb + 2*cc*xi + 3*dd*xi2; + + nn[0] = -der * x[0] / rr; + nn[1] = -der * x[1] / rr; + }else{ + nn[0] = nn[1] = 0.0; + } +} + +double manifold_gaussian_bump::g_and_n( const double *x, double *nn ) +{ + double xf[3]; + xf[0] = x[0]; + xf[1] = x[1]; + xf[2] = 0.0; + nn[2] = 1.0; + + double x2 = dot(xf,xf); + if( x2 < rc12 ){ + double gb = gaussian_bump_x2(x2); + double factor = gb / (ll*ll); + nn[0] = factor * x[0]; + nn[1] = factor * x[1]; + + return x[2] - gb; + }else if( x2 < rc22 ){ + + double rr = sqrt(x2); + double xi = rr - rc1; + xi *= inv_dr; + double xi2 = x2 * inv_dr*inv_dr; + double xi3 = xi*xi2; + + double der = bb + 2*cc*xi + 3*dd*xi2; + + nn[0] = -der * x[0] / rr; + nn[1] = -der * x[1] / rr; + + + return x[2] - ( aa + bb*xi + cc*xi2 + dd*xi3 ); + + }else{ + nn[0] = nn[1] = 0.0; + return x[2]; + } + +} + + +void manifold_gaussian_bump::post_param_init() +{ + // Read in the params: + AA = params[0]; + ll = params[1]; + rc1 = params[2]; + rc2 = params[3]; + + ll2 = 2.0*ll*ll; + + f_at_rc = gaussian_bump_x2 ( rc12 ); + fp_at_rc = gaussian_bump_der( rc12 ); + + rc12 = rc1*rc1; + rc22 = rc2*rc2; + dr = rc2 - rc1; + inv_dr = 1.0 / dr; +} + + +double manifold_gaussian_bump::gaussian_bump( double x ) +{ + double x2 = x*x; + return gaussian_bump_x2( x2 ); +} + +double manifold_gaussian_bump::gaussian_bump_x2( double x2 ) +{ + return AA*exp( -x2 / ll2 ); +} + +double manifold_gaussian_bump::gaussian_bump_der( double x ) +{ + double x2 = x*x; + return gaussian_bump_x2( x2 )*( -x/(ll*ll) ); +} diff --git a/src/USER-MANIFOLD/manifold_gaussian_bump.h b/src/USER-MANIFOLD/manifold_gaussian_bump.h new file mode 100644 index 0000000000000000000000000000000000000000..43f69fba185512a4a25282df31aa97535f599875 --- /dev/null +++ b/src/USER-MANIFOLD/manifold_gaussian_bump.h @@ -0,0 +1,79 @@ +/* ---------------------------------------------------------------------- + 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, s.paquay@tue.nl + 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 **) : manifold(lmp) {} + 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, bb, cc, dd, AA, ll, ll2, f_at_rc, fp_at_rc; + double rc1, rc2, rc12, rc22, dr, inv_dr; + + double gaussian_bump ( double ); + double gaussian_bump_x2 ( double ); + double gaussian_bump_der( double ); + + }; +} + +} + + +#endif // LMP_MANIFOLD_GAUSSIAN_BUMP_H