int vtCStreamLine::AdvectOneStep(TIME_DIR time_dir,
INTEG_ORD integ_ord,
TIME_DEP time_dep,
PointInfo& seedInfo,
VECTOR3& finalP)
{
int istat;
PointInfo thisParticle;
VECTOR3 vel;
float curTime = m_fCurrentTime;
float dt = m_fInitialStepSize;
finalP.Set(-1, -1, -1);
thisParticle = seedInfo;
// the first point
istat = m_pField->at_phys(seedInfo.fromCell, seedInfo.phyCoord,
seedInfo, m_fCurrentTime, vel);
if(istat == OUT_OF_BOUND)
return OUT_OF_BOUND;
if((fabs(vel[0]) < m_fStationaryCutoff) &&
(fabs(vel[1]) < m_fStationaryCutoff) &&
(fabs(vel[2]) < m_fStationaryCutoff))
return CRITICAL_POINT;
float error;
if(integ_ord == SECOND)
istat = runge_kutta2(time_dir, time_dep, thisParticle, &curTime, dt);
else if(integ_ord == FOURTH)
istat = runge_kutta4(time_dir, time_dep, thisParticle, &curTime, dt);
else if(integ_ord == RK45)
istat = runge_kutta45(time_dir, time_dep, thisParticle, &curTime, dt,
&error);
else
return OUT_OF_BOUND;
if(istat == OUT_OF_BOUND) // out of boundary
return OUT_OF_BOUND;
m_pField->at_phys(thisParticle.fromCell, thisParticle.phyCoord,
thisParticle, m_fCurrentTime, vel);
if((fabs(vel[0]) < m_fStationaryCutoff) &&
(fabs(vel[1]) < m_fStationaryCutoff) &&
(fabs(vel[2]) < m_fStationaryCutoff))
return CRITICAL_POINT;
else
finalP = thisParticle.phyCoord;
return OKAY;
}
//////////////////////////////////////////////////////////////////////////
// Perform one proper integration step, taking into account error metrics. This
// is used for integration methods that rely on a geometric error analysis
// based on the angle greated by the new step.
//
// return FAIL or OKAY
//
//////////////////////////////////////////////////////////////////////////
int vtCFieldLine::oneStepGeometric(INTEG_ORD integ_ord, TIME_DIR time_dir,
TIME_DEP time_dep, PointInfo& thisParticle,
PointInfo prevParticle,
PointInfo second_prevParticle,
float* curTime, float* dt, int count)
{
int istat;
PointInfo tempParticle = thisParticle;
float prevTime = *curTime;
int pass = 0;
while(!pass)
{
// take a step
if(integ_ord == SECOND)
istat = runge_kutta2(time_dir, time_dep, thisParticle, curTime,*dt);
else if(integ_ord == FOURTH)
istat = runge_kutta4(time_dir, time_dep, thisParticle, curTime,*dt);
else
return OUT_OF_BOUND;
if(istat == FAIL)
return FAIL;
if(count >= 2)
{
pass = adapt_step(second_prevParticle.phyCoord,
prevParticle.phyCoord, thisParticle.phyCoord, dt);
if(!pass)
{
// revert to before the step was taken
*curTime = prevTime;
thisParticle = tempParticle;
}
}
else
{
pass = 1;
}
}
return OKAY;
}
//////////////////////////////////////////////////////////////////////////
// advect the particle from initialTime to finalTime
//////////////////////////////////////////////////////////////////////////
int vtCTimeVaryingFieldLine::advectParticle(INTEG_ORD int_order,
vtParticleInfo& initialPoint,
float initialTime,
vtParticleInfo& finalPoint,
float finalTime)
{
int istat;
float curTime, dt;
PointInfo pt;
pt = initialPoint.m_pointInfo;
if(m_itsTimeAdaptionFlag == 1)
dt = (finalTime - initialTime) * 0.5;
else
dt = finalTime - initialTime;
curTime = initialTime;
while(curTime < finalTime)
{
float error;
if(int_order == SECOND)
istat = runge_kutta2(m_timeDir, UNSTEADY, pt, &curTime, dt);
else if(int_order == FOURTH)
istat = runge_kutta4(m_timeDir, UNSTEADY, pt, &curTime, dt);
else if(int_order == RK45)
istat = runge_kutta45(m_timeDir, UNSTEADY, pt, &curTime,dt,&error);
else
return OUT_OF_BOUND;
if(istat != OKAY)
return istat;
}
finalPoint.m_pointInfo = pt;
return istat;
}
std::vector<double>
crk4(class Container1<functor_type>::iterator funct_iter1,
class Container1<functor_type>::iterator funct_iter2,
class Container2<coord_type>::iterator coord_iter1,
class Container2<coord_type>::iterator coord_iter2,
t_type t,
double h)
{
auto k1 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m1 = midpt(k1, coord_iter1, h);
t += 0.5*h;
auto k2 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m2 = midpt(k1, coord_iter1, h);
auto k3 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m3 = midpt(k1, coord_iter1, h);
t += 0.5*h;
auto k4 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto coord_next = runge_kutta4(coord_iter1, coord_iter2,
k1.begin(), k2.begin(), k3.begin(), k4.begin(),
h);
return coord_next;
}
