#include <SwimDefStepper.h>
Inheritance diagram for SwimDefStepper::DerivFunc:
Public Member Functions | |
| DerivFunc () | |
| DerivFunc (double q, BField *f) | |
| virtual | ~DerivFunc () |
| void | SetChargeBField (double q, BField *b) |
| virtual void | operator() (double x, const double *y, double *dydx) |
Private Attributes | |
| double | fForceCoef |
| BField * | fBfield |
|
|
Definition at line 50 of file SwimDefStepper.h. References fBfield. 00050 : fBfield(0) {;}
|
|
||||||||||||
|
Definition at line 125 of file SwimDefStepper.cxx. References SetChargeBField(). 00126 {
00127 // Initialize force coeff. and BField
00128 this->SetChargeBField(q,b);
00129 }
|
|
|
Definition at line 52 of file SwimDefStepper.h. 00052 {;}
|
|
||||||||||||||||
|
Implements NmOdeDerivFunc. Definition at line 144 of file SwimDefStepper.cxx. References fBfield, fForceCoef, and BField::GetBField(). 00147 {
00148 //const double oneOverSqrt2 = 1./sqrt(2.);
00149 // y[0] - x coordinate (base length units)
00150 // y[1] - y coordinate (base length units)
00151 // y[2] - z coordinate (base length units)
00152 // y[3] - x momentum (base momentum units)
00153 // y[4] - y momentum (base momentum units)
00154 // y[5] - z momentum (base momentum units)
00155 double ptotSqr = y[3]*y[3]+y[4]*y[4]+y[5]*y[5];
00156 if (ptotSqr != 0.0) {
00157 double oneOverPtot = 1.0/TMath::Sqrt(ptotSqr);
00158 dydx[0] = y[3]*oneOverPtot; // (d/ds)x = Px/Ptot
00159 dydx[1] = y[4]*oneOverPtot; // (d/ds)y = Py/Ptot
00160 dydx[2] = y[5]*oneOverPtot; // (d/ds)z = Pz/Ptot
00161
00162 //the point is passed in in xyz, even though the measurements are in uvz -
00163 //the rotation is done in the fitter.
00164 TVector3 xyz(y[0],y[1],y[2]);
00165
00166 //since the Bfield is also in xyz, we are all happy.
00167 TVector3 B = fBfield->GetBField(xyz);
00168
00169 // Calculate derivatives
00170 double qOverE = fForceCoef*oneOverPtot;
00171 dydx[3] = (y[4]*B[2]-y[5]*B[1])*qOverE; // dP/ds = q*(p x B)/E/v
00172 dydx[4] = (y[5]*B[0]-y[3]*B[2])*qOverE; // dP/ds = q*(p x B)/E/v
00173 dydx[5] = (y[3]*B[1]-y[4]*B[0])*qOverE; // dP/ds = q*(p x B)/E/v
00174 }
00175 else {
00176 // Particle is stopped
00177 dydx[0] = 0.0;
00178 dydx[1] = 0.0;
00179 dydx[2] = 0.0;
00180 dydx[3] = 0.0;
00181 dydx[4] = 0.0;
00182 dydx[5] = 0.0;
00183 }
00184 }
|
|
||||||||||||
|
Definition at line 133 of file SwimDefStepper.cxx. References fBfield, and fForceCoef. Referenced by DerivFunc(), and SwimDefStepper::StepOnce(). 00134 {
00135 // The units conversion is c[m/s]*[eV]/[GeV]
00136 static const double unitsC =
00137 (Mphysical::c_light/(Munits::m/Munits::s))/1.0e9;
00138 fForceCoef = unitsC*q;
00139 fBfield = b;
00140 }
|
|
|
Definition at line 57 of file SwimDefStepper.h. Referenced by DerivFunc(), operator()(), and SetChargeBField(). |
|
|
Definition at line 56 of file SwimDefStepper.h. Referenced by operator()(), and SetChargeBField(). |
1.3.9.1