HelixBarrelPlaneCrossing2OrderLocal Class Reference

#include <HelixBarrelPlaneCrossing2OrderLocal.h>

Public Types
typedef Surface::GlobalPoint	GlobalPoint
typedef Surface::GlobalVector	GlobalVector
typedef Surface::LocalPoint	LocalPoint
typedef Surface::LocalVector	LocalVector

Public Member Functions
LocalVector	direction () const
	HelixBarrelPlaneCrossing2OrderLocal (const GlobalPoint &startingPos, const GlobalVector &startingDir, float rho, const Plane &plane)
LocalPoint	position () const

Static Public Member Functions
static LocalPoint	positionOnly (const GlobalPoint &startingPos, const GlobalVector &startingDir, float rho, const Plane &plane)

Private Attributes
LocalVector	theDir
LocalPoint	thePos

Detailed Description

Calculates an approximate crossing of a helix and a barrel plane. The helix circle is approximated with a parabola. The current class name is misleading, since it does not have the HelixPlaneCrossing interface.

Definition at line 12 of file HelixBarrelPlaneCrossing2OrderLocal.h.

Member Typedef Documentation

typedef Surface::GlobalPoint HelixBarrelPlaneCrossing2OrderLocal::GlobalPoint

Definition at line 15 of file HelixBarrelPlaneCrossing2OrderLocal.h.

typedef Surface::GlobalVector HelixBarrelPlaneCrossing2OrderLocal::GlobalVector

Definition at line 16 of file HelixBarrelPlaneCrossing2OrderLocal.h.

typedef Surface::LocalPoint HelixBarrelPlaneCrossing2OrderLocal::LocalPoint

Definition at line 17 of file HelixBarrelPlaneCrossing2OrderLocal.h.

typedef Surface::LocalVector HelixBarrelPlaneCrossing2OrderLocal::LocalVector

Definition at line 18 of file HelixBarrelPlaneCrossing2OrderLocal.h.

Constructor & Destructor Documentation

HelixBarrelPlaneCrossing2OrderLocal::HelixBarrelPlaneCrossing2OrderLocal	(	const GlobalPoint &	startingPos,
		const GlobalVector &	startingDir,
		float	rho,
		const Plane &	plane
	)

Definition at line 6 of file HelixBarrelPlaneCrossing2OrderLocal.cc.

References funct::abs(), ztail::d, dir, f, theDir, thePos, toLocal(), x, PV3DBase< T, PVType, FrameType >::x(), y, PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

{

  typedef Basic2DVector<float>  Vector2D;

  // translate problem to local frame of the plane
 Plane::ToLocal toLocal(plane); 
 LocalPoint lPos = toLocal.toLocal(startingPos);
 LocalVector lDir = toLocal.toLocal(startingDir);

  // check if local frame is already special (local Y axis == global Z axis)
  LocalVector yPrime = toLocal.toLocal( GlobalVector(0,0,1.f));
  // LocalVector diff = yPrime - LocalVector(0,-1.f,0);
  float sinPhi=0, cosPhi=0;
  bool rotated;
  Vector2D pos;
  Vector2D dir;

  if ( std::abs(yPrime.y()) >  0.9999f ) {

    // cout << "Plane already oriented, yPrime = " << yPrime << endl;

    // we are already in the special orientation
    pos = Vector2D( lPos.x(), lPos.y());
    dir = Vector2D( lDir.x(), lDir.y());;
    rotated = false;
  }
  else {

    // cout << "Plane needs rotation, yPrime = " << yPrime << endl;

    // we need to rotate the problem 
    sinPhi = yPrime.y();
    cosPhi = yPrime.x();
    pos = Vector2D( lPos.x()*cosPhi + lPos.y()*sinPhi,
            -lPos.x()*sinPhi + lPos.y()*cosPhi);
    dir = Vector2D( lDir.x()*cosPhi + lDir.y()*sinPhi,
            -lDir.x()*sinPhi + lDir.y()*cosPhi);
    rotated = true;
  }

  float d = -lPos.z();
  float x = pos.x() + dir.x()/lDir.z()*d - 0.5f*rho*d*d;
  float y = pos.y() + dir.y()/lDir.z()*d;

//    cout << "d= " << d << ", pos.x()= " << pos.x() 
//         << ", dir.x()/lDir.z()= " << dir.x()/lDir.z() 
//         << ", 0.5*rho*d*d= " << 0.5*rho*d*d << endl;

  if (!rotated) {
    thePos = LocalPoint( x, y, 0);
    theDir = LocalVector( dir.x()+rho*d, dir.y(), lDir.z());
  }
  else {
    thePos = LocalPoint( x*cosPhi - y*sinPhi,
             x*sinPhi + y*cosPhi, 0);
    float px = dir.x()+rho*d;
    theDir = LocalVector( px*cosPhi - dir.y()*sinPhi,
              px*sinPhi + dir.y()*cosPhi, lDir.z());
  }
}

Member Function Documentation

LocalVector HelixBarrelPlaneCrossing2OrderLocal::direction ( ) const

inline

Definition at line 26 of file HelixBarrelPlaneCrossing2OrderLocal.h.

References theDir.

{ return theDir;}

LocalPoint HelixBarrelPlaneCrossing2OrderLocal::position ( ) const

inline

Definition at line 25 of file HelixBarrelPlaneCrossing2OrderLocal.h.

References thePos.

{ return thePos;}

LocalPoint HelixBarrelPlaneCrossing2OrderLocal::positionOnly ( const GlobalPoint &  startingPos, const GlobalVector &  startingDir, float  rho, const Plane &  plane  )

static

Definition at line 71 of file HelixBarrelPlaneCrossing2OrderLocal.cc.

References funct::abs(), ztail::d, dir, f, toLocal(), x, PV3DBase< T, PVType, FrameType >::x(), y, PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

                                                     {

 typedef Basic2DVector<float>  Vector2D;

  // translate problem to local frame of the plane
 Plane::ToLocal toLocal(plane); 
 LocalPoint lPos = toLocal.toLocal(startingPos);
 LocalVector lDir = toLocal.toLocal(startingDir);

  // check if local frame is already special (local Y axis == global Z axis)
  LocalVector yPrime = toLocal.toLocal( GlobalVector(0,0,1.f));
  // LocalVector diff = yPrime - LocalVector(0,-1.f,0);
  float sinPhi=0, cosPhi=0;
  bool rotated;
  Vector2D pos;
  Vector2D dir;

  if ( std::abs(yPrime.y()) >  0.9999f ) {

    // cout << "Plane already oriented, yPrime = " << yPrime << endl;

    // we are already in the special orientation
    pos = Vector2D( lPos.x(), lPos.y());
    dir = Vector2D( lDir.x(), lDir.y());;
    rotated = false;
  } else {

    // cout << "Plane needs rotation, yPrime = " << yPrime << endl;

    // we need to rotate the problem 
    sinPhi = yPrime.y();
    cosPhi = yPrime.x();
    pos = Vector2D( lPos.x()*cosPhi + lPos.y()*sinPhi,
            -lPos.x()*sinPhi + lPos.y()*cosPhi);
    dir = Vector2D( lDir.x()*cosPhi + lDir.y()*sinPhi,
            -lDir.x()*sinPhi + lDir.y()*cosPhi);
    rotated = true;
  }

  float d = -lPos.z();
  float x = pos.x() + dir.x()/lDir.z()*d - 0.5f*rho*d*d;
  float y = pos.y() + dir.y()/lDir.z()*d;

//    cout << "d= " << d << ", pos.x()= " << pos.x() 
//         << ", dir.x()/lDir.z()= " << dir.x()/lDir.z() 
//         << ", 0.5*rho*d*d= " << 0.5*rho*d*d << endl;

  return (!rotated) ? LocalPoint( x, y, 0) :
    LocalPoint( x*cosPhi - y*sinPhi,
        x*sinPhi + y*cosPhi, 0);


}

Member Data Documentation

LocalVector HelixBarrelPlaneCrossing2OrderLocal::theDir

private

Definition at line 36 of file HelixBarrelPlaneCrossing2OrderLocal.h.

Referenced by direction(), and HelixBarrelPlaneCrossing2OrderLocal().

LocalPoint HelixBarrelPlaneCrossing2OrderLocal::thePos

private

Definition at line 35 of file HelixBarrelPlaneCrossing2OrderLocal.h.

Referenced by HelixBarrelPlaneCrossing2OrderLocal(), and position().