MyFCN Class Reference

Inherits FCNBase.

Public Member Functions
	MyFCN (std::vector< QwHit * > fhits)
double	operator() (const double *array) const
double	operator() (const std::vector< double > &fit) const
double	Up () const

Private Attributes
std::vector< QwHit * >	hits

Detailed Description

-----------------------------------------------------------------------—*\ Minuit2 Set-up The following is the code that the minuit2 minimizer calls in r2_PartialTrackFit to optimize the fit parameters. It applies rotation parameters defined in the geofile (qweak_HDC.<runrange>.geo) found in the QwAnalysis/Tracking/src/ directory. These rotation parameters (defined by plane) allow the individual planes in Region 2 to be rotated around the center of each chamber. this eventually needs to be corrected to have both chambers in a package rotate around the same point

Definition at line 1517 of file QwTrackingTreeCombine.cc.

Constructor & Destructor Documentation

MyFCN::MyFCN ( std::vector< QwHit * >  fhits )

inline

Definition at line 1521 of file QwTrackingTreeCombine.cc.

: hits(fhits)  {}

Member Function Documentation

double MyFCN::operator() ( const double *  array ) const

inline

Definition at line 1523 of file QwTrackingTreeCombine.cc.

                                                              {
                        const std::vector<double> fit(array, array + 4);
                        return operator()(fit);
                }

double MyFCN::operator() ( const std::vector< double > &  fit ) const

inline

Definition at line 1528 of file QwTrackingTreeCombine.cc.

                                                            {
      double value = 0;
      double chi2 = 0;
      double resolution = hits[0]->GetDetectorInfo()->GetSpatialResolution();
      double normalization = 1/(resolution*resolution);


      // Calculate the metric matrix
      double dx_[12] = { 0.0 };
      double l[3] = { 0.0 };
      double h[3] = { 0.0 };
      for (size_t i = 0; i < hits.size(); ++i)
        dx_[hits[i]->GetPlane() - 1] = hits[i]->GetDetectorInfo()->GetPlaneOffset();

      for (size_t i = 0; i < 3; ++i)
      {
        h[i] = dx_[6 + i] == 0 ? dx_[9 + i] : dx_[6 + i];
        l[i] = dx_[i] == 0 ? dx_[3 + i] : dx_[i];
        dx_[i] = dx_[3 + i] = 0;
        dx_[6 + i] = dx_[9 + i] = h[i] - l[i];
      }

      for (size_t i=0; i<hits.size();i++)
      {

        double cosx = hits[i]->GetDetectorInfo()->GetDetectorRollCos();
        double sinx = hits[i]->GetDetectorInfo()->GetDetectorRollSin();
        double cosy = hits[i]->GetDetectorInfo()->GetDetectorPitchCos();
        double siny = hits[i]->GetDetectorInfo()->GetDetectorPitchSin();
        double rcos = hits[i]->GetDetectorInfo()->GetElementAngleCos();
        double rsin = hits[i]->GetDetectorInfo()->GetElementAngleSin();

        double dx = dx_[hits[i]->GetPlane() - 1];

        double wire_off = -0.5 * hits[i]->GetDetectorInfo()->GetElementSpacing()
            + hits[i]->GetDetectorInfo()->GetElementOffset();
        double hit_pos = hits[i]->GetDriftPosition() + wire_off - dx;

        // Get end points of the hit wire
        double x0 = hit_pos/rsin;
        double y0 = hit_pos/rcos;
    
        double zRot = 1e6;  
        if(hits[i]->GetPackage()==1) zRot = -315.9965; 
        if(hits[i]->GetPackage()==2) zRot = -315.33;

        double z0 = hits[i]->GetDetectorInfo()->GetZPosition();
        double zD = z0 - zRot;
  
        double xR_1 = x0;
        double yR_1 = 0.0;
        double zR_1 = z0;
        double xR_2 = 0.0;
        double yR_2 = y0;
        double zR_2 = z0;
  
        xR_1 = cosy*x0 +zD*cosx*siny;
        yR_1 = zD*sinx;
        zR_1 = zD*cosx*cosy + zRot - siny*x0;
        
        xR_2 = zD*cosx*siny - siny*sinx*y0;
        yR_2 = cosx*y0 + zD*sinx;
        zR_2 = zD*cosx*cosy + zRot - sinx*cosy*y0;

        double xc = hits[i]->GetDetectorInfo()->GetXPosition();
        double yc = hits[i]->GetDetectorInfo()->GetYPosition();
        
        double z = (-(fit[1]-xc-zD*cosx*siny)*cosx*siny - 
               (fit[3]-yc-zD*sinx)*sinx*(cosy*cosy-siny*siny) + 
               (zRot + zD*cosx*cosy)*cosy*cosx)  / 
               (fit[0]*cosx*siny + fit[2]*sinx*(cosy*cosy-siny*siny) + cosy*cosx);  
        
        double x = fit[1] + fit[0] * z;
        double y = fit[3] + fit[2] * z;
      
  
        x -= xc;
        y -= yc;
      
        double diffx = xR_2 - xR_1;
        double diffy = yR_2 - yR_1;
        double diffz = zR_2 - zR_1;

        double numx = -y*diffz + z*diffy + yR_1*zR_2 - yR_2*zR_1;
        double numy =  x*diffz - z*diffx - xR_1*zR_2 + xR_2*zR_1;
        double numz = -x*diffy + y*diffx + xR_1*yR_2 - xR_2*yR_1;
        
        double num = sqrt(numx*numx + numy*numy + numz*numz);

        double demx = xR_2 - xR_1;
        double demy = yR_2 - yR_1;
        double demz = zR_2 - zR_1;
        double dem = sqrt(demx*demx + demy*demy + demz*demz);
        
        double residual = num / dem;

        chi2 += normalization * residual * residual;
      }
      chi2 /= (hits.size() - 4);
      return chi2;


    } 

double MyFCN::Up ( ) const

inline

Definition at line 1633 of file QwTrackingTreeCombine.cc.

{ return 1.; }

Field Documentation

std::vector<QwHit*> MyFCN::hits

private

Definition at line 1639 of file QwTrackingTreeCombine.cc.

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The documentation for this class was generated from the following file:

• QwTrackingTreeCombine.cc