git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@26 f3b2605a-c512-4ea7-a41b-209d697bcdaa

2006-09-27 19:51:33 +00:00
parent 3422cb245c
commit 222c95507e
536 changed files with 108384 additions and 0 deletions
--- a/src/fix_gravity.cpp
+++ b/src/fix_gravity.cpp
@ -0,0 +1,146 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   www.cs.sandia.gov/~sjplimp/lammps.html
+   Steve Plimpton, sjplimp@sandia.gov, Sandia National Laboratories
+
+   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 "math.h"
+#include "stdio.h"
+#include "stdlib.h"
+#include "string.h"
+#include "fix_gravity.h"
+#include "atom.h"
+#include "update.h"
+#include "error.h"
+
+/* ---------------------------------------------------------------------- */
+
+FixGravity::FixGravity(int narg, char **arg) : Fix(narg, arg)
+{
+  if (narg < 4) error->all("Illegal fix gravity command");
+
+  if (strcmp(arg[3],"chute") == 0) {
+    if (narg != 5) error->all("Illegal fix gravity command");
+    if (atom->check_style("granular") == 0)
+      error->all("Must use fix gravity chute with atom style granular");
+    dynamic = 0;
+    granular = 1;
+    phi = 0.0;
+    theta = 180.0 - atof(arg[4]);
+  } else if (strcmp(arg[3],"spherical") == 0) {
+    if (narg != 6) error->all("Illegal fix gravity command");
+    if (atom->check_style("granular") == 0)
+      error->all("Must use fix gravity spherical with atom style granular");
+    dynamic = 0;
+    granular = 1;
+    phi = atof(arg[4]);
+    theta = atof(arg[5]);
+  } else if (strcmp(arg[3],"gradient") == 0) {
+    if (narg != 8) error->all("Illegal fix gravity command");
+    if (atom->check_style("granular") == 0)
+      error->all("Must use fix gravity gradient with atom style granular");
+    dynamic = 1;
+    granular = 1;
+    phi = atof(arg[4]);
+    theta = atof(arg[5]);
+    phigrad = atof(arg[6]);
+    thetagrad = atof(arg[7]);
+  } else if (strcmp(arg[3],"vector") == 0) {
+    if (narg != 8) error->all("Illegal fix gravity command");
+    if (atom->check_style("granular") != 0)
+      error->all("Cannot use fix gravity vector with atom style granular");
+    dynamic = 0;
+    granular = 0;
+    magnitude = atof(arg[4]);
+    xdir = atof(arg[5]);
+    ydir = atof(arg[6]);
+    zdir = atof(arg[7]);
+  } else error->all("Illegal fix gravity command");
+
+  double PI = 2.0 * asin(1.0);
+  degree2rad = 2.0*PI / 360.0;
+  time_initial = update->ntimestep;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int FixGravity::setmask()
+{
+  int mask = 0;
+  mask |= POST_FORCE;
+  return mask;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGravity::init()
+{
+  dt = update->dt;
+
+  if (granular) {
+    xgrav = sin(degree2rad * theta) * cos(degree2rad * phi);
+    ygrav = sin(degree2rad * theta) * sin(degree2rad * phi);
+    zgrav = cos(degree2rad * theta);
+  } else {
+    double length = sqrt(xdir*xdir + ydir*ydir + zdir*zdir);
+    xgrav = magnitude * xdir/length;
+    ygrav = magnitude * ydir/length;
+    zgrav = magnitude * zdir/length;
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGravity::setup()
+{
+  post_force(1);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGravity::post_force(int vflag)
+{
+  // update direction of gravity vector if dynamic
+
+  if (dynamic) {
+    double phi_current = degree2rad * 
+      (phi + (update->ntimestep-time_initial)*dt*phigrad*360.0);
+    double theta_current = degree2rad * 
+      (theta + (update->ntimestep-time_initial)*dt*thetagrad*360.0);
+    xgrav = sin(theta_current) * cos(phi_current);
+    ygrav = sin(theta_current) * sin(phi_current);
+    zgrav = cos(theta_current);
+  }
+
+  double **f = atom->f;
+  double *rmass = atom->rmass;
+  double *mass = atom->mass;
+  int *mask = atom->mask;
+  int *type = atom->type;
+  int nlocal = atom->nlocal;
+  double massone;
+
+  if (granular) {
+    for (int i = 0; i < nlocal; i++)
+      if (mask[i] & groupbit) {
+	f[i][0] += rmass[i]*xgrav;
+	f[i][1] += rmass[i]*ygrav;
+	f[i][2] += rmass[i]*zgrav;
+      }
+  } else {
+    for (int i = 0; i < nlocal; i++)
+      if (mask[i] & groupbit) {
+	massone = mass[type[i]];
+	f[i][0] += massone*xgrav;
+	f[i][1] += massone*ygrav;
+	f[i][2] += massone*zgrav;
+      }
+  }
+}