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 69 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(), DifVector::errorMatrix(), and sAph1().

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 )

extern

Definition at line 91 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