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git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@1160 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2007-11-13 23:03:16 +00:00
parent 51201e0a8e
commit 21bc238b0c
2 changed files with 42 additions and 4 deletions
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43
src/fix_spring.cpp
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@ -38,6 +38,11 @@ FixSpring::FixSpring(LAMMPS *lmp, int narg, char **arg) :
{
if (narg < 9) error->all("Illegal fix spring command");
vector_flag = 1;
size_vector = 3;
scalar_vector_freq = 1;
extensive = 1;
if (strcmp(arg[3],"tether") == 0) {
if (narg != 9) error->all("Illegal fix spring command");
styleflag = TETHER;
@ -147,13 +152,22 @@ void FixSpring::spring_tether()
double *mass = atom->mass;
int nlocal = atom->nlocal;
ftotal[0] = ftotal[1] = ftotal[2] = 0.0;
force_flag = 0;
double massfrac;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
massfrac = mass[type[i]]/masstotal;
f[i][0] -= fx*massfrac;
f[i][1] -= fy*massfrac;
f[i][2] -= fz*massfrac;
fx *= massfrac;
fy *= massfrac;
fz *= massfrac;
f[i][0] -= fx;
f[i][1] -= fy;
f[i][2] -= fz;
ftotal[0] -= fx;
ftotal[1] -= fy;
ftotal[2] -= fz;
}
}
@ -190,7 +204,10 @@ void FixSpring::spring_couple()
int *type = atom->type;
double *mass = atom->mass;
int nlocal = atom->nlocal;
ftotal[0] = ftotal[1] = ftotal[2] = 0.0;
force_flag = 0;
double massfrac;
for (int i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
@ -198,6 +215,9 @@ void FixSpring::spring_couple()
f[i][0] += fx*massfrac;
f[i][1] += fy*massfrac;
f[i][2] += fz*massfrac;
ftotal[0] += fx*massfrac;
ftotal[1] += fy*massfrac;
ftotal[2] += fz*massfrac;
}
if (mask[i] & group2bit) {
massfrac = mass[type[i]]/masstotal2;
@ -214,3 +234,18 @@ void FixSpring::post_force_respa(int vflag, int ilevel, int iloop)
{
if (ilevel == nlevels_respa-1) post_force(vflag);
}
/* ----------------------------------------------------------------------
return components of total spring force on fix group
------------------------------------------------------------------------- */
double FixSpring::compute_vector(int n)
{
// only sum across procs one time
if (force_flag == 0) {
MPI_Allreduce(ftotal,ftotal_all,3,MPI_DOUBLE,MPI_SUM,world);
force_flag = 1;
}
return ftotal_all[n];
}

3
src/fix_spring.h
View File

@ -26,6 +26,7 @@ class FixSpring : public Fix {
void setup();
void post_force(int);
void post_force_respa(int, int, int);
double compute_vector(int);
private:
double xc,yc,zc,r0;
@ -35,6 +36,8 @@ class FixSpring : public Fix {
int igroup2,group2bit;
double masstotal,masstotal2;
int nlevels_respa;
double ftotal[3],ftotal_all[3];
int force_flag;
void spring_tether();
void spring_couple();