ICODE-ADC/lammps
4
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@622 f3b2605a-c512-4ea7-a41b-209d697bcdaa

Browse Source
This commit is contained in:
sjplimp
2007-06-20 13:17:59 +00:00
parent bde732bced
commit aaed6ebc33
131 changed files with 4277 additions and 2222 deletions
Download Patch File Download Diff File Expand all files Collapse all files

83
src/velocity.cpp
View File

@ -278,12 +278,22 @@ void Velocity::create(int narg, char **arg)
}
} else if (loop_flag == GEOM) {
random = new RanPark(lmp,seed);
random = new RanPark(lmp,1);
double **x = atom->x;
for (i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
triple(x[i],&vx,&vy,&vz,seed,random);
random->reset(seed,x[i]);
if (dist_flag == 0) {
vx = random->uniform();
vy = random->uniform();
vz = random->uniform();
} else {
vx = random->gaussian();
vy = random->gaussian();
vz = random->gaussian();
}
if (mass) factor = 1.0/sqrt(mass[type[i]]);
else factor = 1.0/sqrt(rmass[i]);
v[i][0] = vx * factor;
@ -648,72 +658,3 @@ void Velocity::options(int narg, char **arg)
} else error->all("Illegal velocity command");
}
}
/* ---------------------------------------------------------------------- */
#define IA1 1366
#define IC1 150889
#define IM1 714025
#define IA2 8121
#define IC2 28411
#define IM2 134456
#define IA3 7141
#define IC3 54773
#define IM3 259200
void Velocity::triple(double *x, double *vx, double *vy, double *vz,
int seed, RanPark *random)
{
// for orthogonal box, lamda = fractional position in box
// for triclinic box, convert to lamda coords
double lamda[3];
if (domain->triclinic == 0) {
lamda[0] = (x[0] - domain->boxlo[0]) / domain->prd[0];
lamda[1] = (x[1] - domain->boxlo[1]) / domain->prd[1];
lamda[2] = (x[2] - domain->boxlo[2]) / domain->prd[2];
} else domain->x2lamda(x,lamda);
// seed 1,2,3 = combination of atom coord in each dim and user-input seed
// map geometric extent into range of each of 3 RNGs
// warm-up each RNG by calling it twice
int seed1,seed2,seed3;
seed1 = static_cast<int> (lamda[0] * IM1);
seed1 = (seed1+seed) % IM1;
seed1 = (seed1*IA1+IC1) % IM1;
seed1 = (seed1*IA1+IC1) % IM1;
seed2 = static_cast<int> (lamda[1] * IM2);
seed2 = (seed2+seed) % IM2;
seed2 = (seed2*IA2+IC2) % IM2;
seed2 = (seed2*IA2+IC2) % IM2;
seed3 = static_cast<int> (lamda[2] * IM3);
seed3 = (seed3+seed) % IM3;
seed3 = (seed3*IA3+IC3) % IM3;
seed3 = (seed3*IA3+IC3) % IM3;
// fraction = 0-1 with giving each dim an equal weighting
// use fraction to reset Park/Miller RNG seed
double fraction = 1.0*seed1/(3*IM1) + 1.0*seed2/(3*IM2) + 1.0*seed3/(3*IM3);
random->reset(fraction);
// use RNG to set velocities after warming up twice
random->uniform();
random->uniform();
if (dist_flag == 0) {
*vx = random->uniform();
*vy = random->uniform();
*vz = random->uniform();
} else {
*vx = random->gaussian();
*vy = random->gaussian();
*vz = random->gaussian();
}
}