void Tracer_unidirectionalTrace(int id, const char * variable, const float * startComponent1, const float * startComponent2,
const float * startComponent3, const int * step_max, const float * dn, int * actual_steps, float * x_array, float * y_array, float * z_array)
{
ccmc::Tracer * tracer = tracerObjects[id];
tracer->setMaxIterations(*step_max);
if (dn < 0)
{
tracer->setDn(-*dn);
Fieldline fieldline = tracer->unidirectionalTrace(variable, *startComponent1, *startComponent2, *startComponent3, ccmc::Tracer::REVERSE);
*actual_steps = fieldline.size();
for (int i = 0; i < fieldline.size(); i++)
{
x_array[i] = fieldline.getPositions()[i].component1;
y_array[i] = fieldline.getPositions()[i].component2;
z_array[i] = fieldline.getPositions()[i].component3;
}
}else
{
tracer->setDn(*dn);
Fieldline fieldline = tracer->unidirectionalTrace(variable, *startComponent1, *startComponent2, *startComponent3, ccmc::Tracer::FOWARD);
*actual_steps = fieldline.size();
for (int i = 0; i < fieldline.size(); i++)
{
x_array[i] = fieldline.getPositions()[i].component1;
y_array[i] = fieldline.getPositions()[i].component2;
z_array[i] = fieldline.getPositions()[i].component3;
}
}
}
int main (int argc, char * argv[])
{
std::string filename;
std::string variable;
float c0;
float c1;
float c2;
int iterations = 10;
if (argc != 6)
{
cout << "integrator <filename> <variable> c0 c1 c2" << endl;
exit(1);
}
filename = argv[1];
variable = argv[2];
c0 = boost::lexical_cast<float>(argv[3]);
c1 = boost::lexical_cast<float>(argv[4]);
c2 = boost::lexical_cast<float>(argv[5]);
cout << "This program will compute the integral for a fieldline of the specified variable" << std::endl;
Kameleon kameleon; //creates a kameleon object capable of working with any of the ccmc-supported models
kameleon.open(filename);
kameleon.loadVectorVariable("b"); //see the namespace ccmc::strings::variables for possible inputs
kameleon.loadVectorVariable("e");
Tracer tracer(&kameleon); // Sets the interpolator (based on the kameleon object) to be used for tracing
tracer.setMaxIterations(20000); //Maximum number of points in the fieldline
tracer.setInnerBoundary(2.5f); //radius where fieldlines should stop (usually larger than the model's inner boundary)
tracer.setDn(.2f); //step size relative to the cell size
clock_t start, finish;
cout << "Initializing field line\n";
Fieldline fieldline;
/*
* Supported tracers: input position is cartesian (x,y,z) unless the model is Enlil (r,theta,phi)
* bidirectionalTrace(string variable, float p0, float p1, float p2)
* bidirectionalTraceWithDipole(string variable, float p0, float p1, float p2)
* unidirectionalTrace(string variable, float p0, float p1, float p2, Direction) where Direction must be keyword FORWARD or REVERSE
* unidirectionalTraceWithDipole(string variable, float p0, float p1, float p2, Direction)
*/
cout << "Bidirectional trace beginning at ("<< c0 << ","<<c1<<","<<c2<<")"<<endl;
start = clock();
fieldline = tracer.bidirectionalTrace("b",c0,c1,c2);
finish = clock();
float elapsed_time = ((double) finish - (double) start) / CLOCKS_PER_SEC;
cout << "Fieldline trace took "<< elapsed_time << " seconds\n"<<endl;
cout << "After bidrectional trace\n";
cout << "Points in fieldline:"<<fieldline.size()<<endl;
//You can retrieve the kameleon object's interpolator from the tracer, thusly:
Interpolator * interpolator = tracer.interpolator; //interpolator will be deleted via the Tracer's destructor
//Or you can make a new one, which is useful for doing interpolations in parallel:
//Interpolator * interpolator = kameleon.createNewInterpolator(); //but make sure you delete it when done
Fieldline fieldlineWithVariable;
Point3f p, eField;
float datum, pEx, pEy, pEz;
for (int i = 0; i < fieldline.size(); i++)
{
p = fieldline.getPosition(i);
datum = interpolator->interpolate(variable,p.component1,p.component2,p.component3);
fieldlineWithVariable.insertPointData(p,datum);
eField.component1 = interpolator->interpolate("ex",p.component1,p.component2,p.component3);
eField.component2 = interpolator->interpolate("ey",p.component1,p.component2,p.component3);
eField.component3 = interpolator->interpolate("ez",p.component1,p.component2,p.component3);
fieldlineWithVariable.insertVectorData(eField); // eField in [mV/m]
}
vector<float> segmentLengths = fieldlineWithVariable.getDs(); //computes line segments of fieldline [Re]
vector<float> integral = fieldlineWithVariable.integrate(); //sum of individual segmentLengths * variable
vector<float> fieldlinePotential = fieldlineWithVariable.integrateVector(); // integral(E dot dl)
std::cout<<"integral result:"<< integral.back()<< "[" << variable << "* Re]"<<endl;
std::cout<<"Fieldline potential:"<< fieldlinePotential.back()*(6.3781e3)<<"[V]\n"; //[V] = [Re*mV/m]*[1V/1000mV]*[6.3781e6 m/Re]
kameleon.close();
//delete interpolator; //required if you used kameleon.createNewInterpolator above
std::cout << "finished" << std::endl;
return 0;
}
