/* This function computes the local velocity dispersion
* of each particle (among particles of the same type)
*/
void veldisp(void)
{
double vsum[3], v2sum[3];
double h, hinv, hinv3;
double rho, wk;
double dx, dy, dz, r, r2, u;
int i,j,k,ii,n,count;
float *r2list;
int *ngblist;
/* only active particles */
for(i=IndFirstUpdate,count=0; count<NumForceUpdate; i=P[i].ForceFlag, count++)
{
if(P[i].Type>0)
{
rho= vsum[0] = vsum[1] = vsum[2] = v2sum[0] = v2sum[1] = v2sum[2] = 0;
P[i].HsmlVelDisp= sqrt(ngb_treefind(P[i].PosPred, All.DesNumNgb,
1.1*P[i].HsmlVelDisp,
P[i].Type, &ngblist, &r2list));
h = P[i].HsmlVelDisp;
hinv = 1.0/h;
hinv3 = hinv*hinv*hinv;
for(n=0; n<All.DesNumNgb; n++)
{
j = ngblist[n]+1;
dx = P[i].PosPred[0] - P[j].PosPred[0];
dy = P[i].PosPred[1] - P[j].PosPred[1];
dz = P[i].PosPred[2] - P[j].PosPred[2];
#ifdef PERIODIC
dx= periodic(dx);
dy= periodic(dy);
dz= periodic(dz);
#endif
r2 = dx*dx + dy*dy + dz*dz;
r = sqrt(r2);
if(r<h)
{
u = r*hinv;
ii = (int)(u*KERNEL_TABLE);
wk =hinv3*( Kernel[ii] + (Kernel[ii+1]-Kernel[ii])*(u-KernelRad[ii])*KERNEL_TABLE);
rho += P[j].Mass * wk;
}
for(k=0; k<3; k++)
{
vsum[k] += P[j].VelPred[k];
v2sum[k] += P[j].VelPred[k]*P[j].VelPred[k];
}
}
P[i].DensVelDisp = rho;
P[i].VelDisp = 0;
for(k=0; k<3; k++)
{
vsum[k] /= All.DesNumNgb;
v2sum[k]/= All.DesNumNgb;
P[i].VelDisp += v2sum[k] - vsum[k]*vsum[k];
}
if(P[i].VelDisp > 0)
P[i].VelDisp= sqrt(P[i].VelDisp);
else
P[i].VelDisp= 0;
}
}
}
/* the function below detects particles that have a number of neighbours
* outside the allowed tolerance range. For these, particles the smoothing
* length is adjusted accordingly. Note that the smoothing length is
*/
void sidm_ensure_neighbours(int mode)
{
#define MAXITER 30
int i, ntot, last=0;
float *r2list;
int *ngblist, count, candidates;
int iter=0;
double save;
/*
int IndFirstUpdateBackup, NumForceUpdateBackup;
IndFirstUpdateBackup= IndFirstUpdate;
NumForceUpdateBackup= NumForceUpdate;
for(i=IndFirstUpdate, count=0; count<NumForceUpdate;
i=P[i].ForceFlag, count++){
P[i].ForceFlagBackup= P[i].ForceFlag;
}
*/
for(i=IndFirstUpdate, count=0, candidates=0; count<NumForceUpdate;
i=P[i].ForceFlag, count++) {
if(P[i].Type>0) {
if(P[i].NgbVelDisp < (All.DesNumNgb-All.MaxNumNgbDeviation) ||
(P[i].NgbVelDisp > (All.DesNumNgb+All.MaxNumNgbDeviation)))
candidates++;
}
}
MPI_Reduce(&candidates, &ntot, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
MPI_Bcast(&ntot, 1, MPI_INT, 0, MPI_COMM_WORLD);
if(ntot > 0) {
//#ifdef FINDNBRLOG
// if(ThisTask==0)
//{
//printf("\n%d particles have too few/too many neighbours in sidm calculation!\n", ntot);
// printf("Now fixing that...\n");
// }
//#endif
for(i=IndFirstUpdate, count=0; count<NumForceUpdate;
i=P[i].ForceFlag, count++)
P[i].Left= P[i].Right= 0;
do {
for(i=1+N_gas, NumForceUpdate= 0, NumSphUpdate=0; i<=NumPart; i++) {
if( P[i].NgbVelDisp < (All.DesNumNgb-All.MaxNumNgbDeviation) ||
P[i].NgbVelDisp > (All.DesNumNgb+All.MaxNumNgbDeviation)) {
if(P[i].Left>0 && P[i].Right>0)
if((P[i].Right-P[i].Left) < 1.0e-3 * P[i].Left)
continue;
if(NumForceUpdate==0)
IndFirstUpdate= i;
else
P[last].ForceFlag= i;
NumForceUpdate++;
last=i;
if(P[i].NgbVelDisp < (All.DesNumNgb-All.MaxNumNgbDeviation))
P[i].Left= dmax(P[i].HsmlVelDisp, P[i].Left);
else
if(P[i].Right!=0)
{
if(P[i].HsmlVelDisp<P[i].Right)
P[i].Right= P[i].HsmlVelDisp;
}
else
P[i].Right= P[i].HsmlVelDisp;
}
}
MPI_Allreduce(&NumForceUpdate, &ntot, 1, MPI_INT, MPI_SUM,
MPI_COMM_WORLD);
if(ntot > 0) {
//#ifdef FINDNBRLOG
// if(ThisTask==0)
//printf("ngb iteration %d. still %d particles\n", iter, ntot);
//#endif
for(i=IndFirstUpdate, count=0; count<NumForceUpdate;
i=P[i].ForceFlag, count++) {
if(iter >= 20) {
printf("i=%d ID=%d Hsml=%g Left=%g Right=%g Ngbs=%d Right-Left=%g\n pos=(%g|%g|%g)\n",
i, P[i].ID, P[i].HsmlVelDisp, P[i].Left, P[i].Right,
P[i].NgbVelDisp, P[i].Right-P[i].Left,
P[i].PosPred[0], P[i].PosPred[1], P[i].PosPred[2]);
}
if(iter == MAXITER) {
printf("ThisTask=%d Mi=(%g|%g|%g) Ma=(%g|%g|%g)\n", ThisTask,
DomainMin[P[i].Type][0], DomainMin[P[i].Type][1],
DomainMin[P[i].Type][2], DomainMax[P[i].Type][0],
DomainMax[P[i].Type][1], DomainMax[P[i].Type][2]);
printf("i=%d ID=%d coord=(%g|%g|%g)\n", i, P[i].ID,
P[i].PosPred[0], P[i].PosPred[1], P[i].PosPred[2]);
printf("ngb_treefind= %g\n", sqrt(ngb_treefind(P[i].PosPred ,
All.DesNumNgb, 0, P[i].Type, &ngblist, &r2list)));
}
if(P[i].Left==0 || P[i].Right==0) {
if(P[i].Right==0 && P[i].NgbVelDisp<15 &&
NtypeLocal[P[i].Type]>All.DesNumNgb) {
P[i].HsmlVelDisp= sqrt(ngb_treefind(P[i].PosPred, All.DesNumNgb,
0, P[i].Type, &ngblist, &r2list));
}
else {
P[i].HsmlVelDisp= P[i].HsmlVelDisp*( 0.5 + 0.5*pow(P[i].NgbVelDisp/((double)All.DesNumNgb), -1.0/3));
}
}
else {
P[i].HsmlVelDisp= 0.5*(P[i].Left + P[i].Right);
}
}
sidm();
iter++;
if(iter > MAXITER) {
fprintf(stdout, "failed to converge in function ensure_neighbours()\n");
endrun(1155);
}
}
} while(ntot > 0);
if(mode == 0) { /* restore timeline to active particles */
/*
IndFirstUpdate= IndFirstUpdateBackup;
NumForceUpdate= NumForceUpdateBackup;
for(i=IndFirstUpdateBackup, count=0; count<NumForceUpdateBackup;
i=P[i].ForceFlagBackup, count++){
P[i].ForceFlag= P[i].ForceFlagBackup;
}
*/
save= All.TimeStep;
find_next_time();
All.TimeStep= save;
}
else { /* make all particles active again */
for(i=1; i<=NumPart; i++)
P[i].ForceFlag=i+1;
P[NumPart].ForceFlag=1;
IndFirstUpdate=1;
NumForceUpdate=NumPart;
NumSphUpdate=N_gas;
}
}
#undef MAXITER
}
