DTLinearFit Class Reference

#include <DTLinearFit.h>

Public Member Functions
	DTLinearFit ()
	Constructor. More...
void	fit (const std::vector< float > &x, const std::vector< float > &y, int ndat, const std::vector< float > &sigy, float &slope, float &intercept, float &covss, float &covii, float &covsi) const
	~DTLinearFit ()
	Destructor. More...

Detailed Description

Description:

detailed description

Author

Stefano Lacaprara - INFN Legnaro stefa.nosp@m.no.l.nosp@m.acapr.nosp@m.ara@.nosp@m.pd.in.nosp@m.fn.i.nosp@m.t

Definition at line 25 of file DTLinearFit.h.

Constructor & Destructor Documentation

DTLinearFit::DTLinearFit

(

)

Constructor.

Definition at line 17 of file DTLinearFit.cc.

                         {

}

DTLinearFit::~DTLinearFit

(

)

Destructor.

Definition at line 22 of file DTLinearFit.cc.

                          {
}

Member Function Documentation

void DTLinearFit::fit	(	const std::vector< float > &	x,
		const std::vector< float > &	y,
		int	ndat,
		const std::vector< float > &	sigy,
		float &	slope,
		float &	intercept,
		float &	covss,
		float &	covii,
		float &	covsi
	)		const

Definition at line 26 of file DTLinearFit.cc.

References diffTwoXMLs::g1, diffTwoXMLs::g2, and i.

Referenced by DTSegmentUpdator::fit().

{

  float g1 = 0, g2 = 0;
  float s11 = 0, s12 = 0, s22 = 0;
  for (int i = 0; i != ndat; i++) {
    float sy2 = sigy[i] * sigy[i];
    g1 += y[i] / sy2;
    g2 += x[i]*y[i] / sy2;
    s11 += 1. / sy2;
    s12 += x[i] / sy2;
    s22 += x[i]*x[i] / sy2;
  }

  float d = s11*s22 - s12*s12;
  intercept = (g1*s22 - g2*s12) / d;
  slope = (g2*s11 - g1*s12) / d;

  covii =  s22 / d;
  covss =  s11 / d;
  covsi = -s12 / d;

}