DifNumber.cxx File Reference

#include "MdcRecoUtil/DifNumber.h"
#include "MdcRecoUtil/DifIndepPar.h"

Go to the source code of this file.

Functions
double	correlation (const DifNumber &a, const DifNumber &b)
double	correlation (const DifNumber &a, const DifNumber &b, const HepSymMatrix &e)
DifNumber	solveQuad (const DifNumber &a, const DifNumber &b, const DifNumber &c, int pref, Code &code)

Variables
const DifNumber	zero (0.0)
const DifNumber	one (1.0)

Function Documentation

correlation() [1/2]

double correlation	(	const DifNumber &	a,
		const DifNumber &	b
	)

Definition at line 72 of file DifNumber.cxx.

{ 
  return (a.indepPar()==0||b.indepPar()==0||a.indepPar()!=b.indepPar())?0:a.correlation(b,a.indepPar()->covariance()); 
}

Referenced by DifFourVector::errorMatrix(), and DifVector::errorMatrix().

correlation() [2/2]

double correlation	(	const DifNumber &	a,
		const DifNumber &	b,
		const HepSymMatrix &	e
	)

Definition at line 78 of file DifNumber.cxx.

{ return a.correlation(b,e); }

solveQuad()

DifNumber solveQuad	(	const DifNumber &	a,
		const DifNumber &	b,
		const DifNumber &	c,
		int	pref,
		Code &	code
	)

Definition at line 90 of file DifNumber.cxx.

{
  DifNumber descr=b*b-4.0*a*c;
  if(descr<0.0) {       // solution not real
    code.setFail(1341);
    return DifNumber(0.0);
  }
  if(a.number()==0.0){
    if(b.number()==0.0) {
      code.setFail(1342);
      return DifNumber(0.0);
    }
    code.setSuccess(40);
    return -c/b+a*c/pow(b,3);
  }
  code.setSuccess(40);
  descr=sqrt(descr);
  DifNumber s=-b;
 
  if(pref==+1) {        // positive solution
    s+=descr;
  }else if(pref==-1){       // negative solution
    s-=descr;
  }else if(pref==0) {       // smallest solution
    if(s>0.0) {s-=descr;}else {s+=descr;}
  }else {           // illegal prefrence
    code.setFail(1343);
    return DifNumber(0.0);
  }
  s/=2.0*a;
  return s;
}

Variable Documentation

one

const DifNumber one(1.0) ( 1.  0 )

extern

zero

const DifNumber zero(0.0) ( 0.  0 )

extern