void makedisk(bool randspin)
{
int i;
bodyptr bp;
double m, r, v, phi;
matrix xmat, zmat;
vector tmpv;
for (i = 0; i < ndisk; i++) { // loop initializing bodies
bp = NthBody(disk, i); // set ptr to body number i
m = mdtab[NTAB-1] * ((double) i + 0.5) / ndisk;
r = gsl_interp_eval(rm_spline, mdtab, rdtab, m, NULL);
v = gsl_interp_eval(vr_spline, rdtab, vctab, r, NULL);
phi = xrandom(0.0, 2 * M_PI);
Pos(bp)[0] = r * sin(phi);
Pos(bp)[1] = r * cos(phi);
Pos(bp)[2] = 0.0;
Vel(bp)[0] = v * cos(phi);
Vel(bp)[1] = - v * sin(phi);
Vel(bp)[2] = 0.0;
pickshell(AuxVec(bp), NDIM, 1.0);
if (randspin) {
xmatrix(xmat, acos(AuxVec(bp)[2]));
zmatrix(zmat, atan2(AuxVec(bp)[0], AuxVec(bp)[1]));
MULMV(tmpv, xmat, Pos(bp));
MULMV(Pos(bp), zmat, tmpv);
MULMV(tmpv, xmat, Vel(bp));
MULMV(Vel(bp), zmat, tmpv);
}
}
}
local void gravsub(nodeptr q)
{
real drab, phii, mor3;
vector ai, quaddr;
real dr5inv, phiquad, drquaddr;
if (q != (long) qmem) { /* cant use memorized data? */
SUBV(dr, Pos(q), pos0); /* then compute sep. */
DOTVP(drsq, dr, dr); /* and sep. squared */
}
drsq += eps*eps; /* use standard softening */
drab = rsqrt(drsq);
phii = Mass(q) / drab;
mor3 = phii / drsq;
MULVS(ai, dr, mor3);
phi0 -= phii; /* add to total grav. pot. */
ADDV(acc0, acc0, ai); /* ... and to total accel. */
if (usequad && Type(q) == CELL) { /* if cell, add quad term */
cellptr SAFE c= TC(q);
dr5inv = 1.0/(drsq * drsq * drab); /* form dr^-5 */
MULMV(quaddr, Quad(c), dr); /* form Q * dr */
DOTVP(drquaddr, dr, quaddr); /* form dr * Q * dr */
phiquad = -0.5 * dr5inv * drquaddr; /* get quad. part of phi */
phi0 = phi0 + phiquad; /* increment potential */
phiquad = 5.0 * phiquad / drsq; /* save for acceleration */
MULVS(ai, dr, phiquad); /* components of acc. */
SUBV(acc0, acc0, ai); /* increment */
MULVS(quaddr, quaddr, dr5inv);
SUBV(acc0, acc0, quaddr); /* acceleration */
}
}
void rotatevec(vector vec, matrix mat)
{
vector tmp;
MULMV(tmp, mat, vec);
SETV(vec, tmp);
}
void gravsub(register nodeptr p, long ProcessId)
{
real drabs, phii, mor3;
vector ai;
if (p != Local[ProcessId].pmem) {
SUBV(Local[ProcessId].dr, Pos(p), Local[ProcessId].pos0);
DOTVP(Local[ProcessId].drsq, Local[ProcessId].dr, Local[ProcessId].dr);
}
Local[ProcessId].drsq += epssq;
drabs = sqrt((double) Local[ProcessId].drsq);
phii = Mass(p) / drabs;
Local[ProcessId].phi0 -= phii;
mor3 = phii / Local[ProcessId].drsq;
MULVS(ai, Local[ProcessId].dr, mor3);
ADDV(Local[ProcessId].acc0, Local[ProcessId].acc0, ai);
if(Type(p) != BODY) { /* a body-cell/leaf interaction? */
Local[ProcessId].mynbcterm++;
#ifdef QUADPOLE
dr5inv = 1.0/(Local[ProcessId].drsq * Local[ProcessId].drsq * drabs);
MULMV(quaddr, Quad(p), Local[ProcessId].dr);
DOTVP(drquaddr, Local[ProcessId].dr, quaddr);
phiquad = -0.5 * dr5inv * drquaddr;
Local[ProcessId].phi0 += phiquad;
phiquad = 5.0 * phiquad / Local[ProcessId].drsq;
MULVS(ai, Local[ProcessId].dr, phiquad);
SUBV(Local[ProcessId].acc0, Local[ProcessId].acc0, ai);
MULVS(quaddr, quaddr, dr5inv);
SUBV(Local[ProcessId].acc0, Local[ProcessId].acc0, quaddr);
#endif
}
else { /* a body-body interaction */
Local[ProcessId].myn2bterm++;
}
}