AliPhysics  ced2227 (ced2227)
LinearSigmaCombiner Struct Reference
Inheritance diagram for LinearSigmaCombiner:

Public Member Functions

double W (const Result &r) const
 
double StepW (double guess, const Result &r) const
 
double StepOffset (double, const Result &) const
 
double TermVar (double guess, const Result &r) const
 
- Public Member Functions inherited from Combiner
virtual ~Combiner ()
 
double Term (double guess, const Result &r) const
 
double F (double guess, double chi2, const_iterator &begin, const_iterator &end) const
 
double FindError (unsigned short nIter, const_iterator &begin, const_iterator &end, int sign, double best, double chi2, double s)
 
double FindX (unsigned short nIter, const_iterator &begin, const_iterator &end, double lowest, double highest)
 
Final Calculate (const_iterator &begin, const_iterator &end, unsigned short nIter=50)
 

Static Public Member Functions

static double L (double guess, double x, double el, double eh)
 
static double WrapL (double *xp, double *pp)
 

Additional Inherited Members

- Public Types inherited from Combiner
typedef List::iterator iterator
 
typedef List::const_iterator const_iterator
 

Detailed Description

A combiner that uses a linear \(\sigma\) approximation

Definition at line 465 of file Combiner.C.

Member Function Documentation

static double LinearSigmaCombiner::L ( double  guess,
double  x,
double  el,
double  eh 
)
inlinestatic

Return the likely-hood function value at \( x'\):

\[ L(x') = \left[(x'-x) / (s + s'(x'-x))\right]^2 \]

where

\[ s = 2\sigma^+\sigma^-/(\sigma^++\sigma^-) \]

\[ s' = (\sigma^+-\sigma^-)/(\sigma^++\sigma^-) \]

Parameters
guess\( x'\)
x\( x\)
el\( \sigma^-\)
eh\( \sigma^+\)
Returns

Definition at line 548 of file Combiner.C.

double LinearSigmaCombiner::StepOffset ( double  ,
const Result  
) const
inlinevirtual

Calculate the bias.

Returns
0

Implements Combiner.

Definition at line 505 of file Combiner.C.

double LinearSigmaCombiner::StepW ( double  guess,
const Result r 
) const
inlinevirtual

Calculate the weight based on a guess of best \( x'\)

\[ w(x') = s / [s + s' (x' - x)]^3 \]

Parameters
guessCurrent guess \( x'\)
rObservation
Returns
\( W(x')\)

Implements Combiner.

Definition at line 495 of file Combiner.C.

double LinearSigmaCombiner::TermVar ( double  guess,
const Result r 
) const
inlinevirtual

Calculate the contribution variance to the \(\chi^2\) with the guess \(x'\).

\[ v(x') = [s + s' (x' - x)]^2 \]

Parameters
guessCurrent guess \( x'\)
rObservation
Returns
\( v(x')\)

Implements Combiner.

Definition at line 522 of file Combiner.C.

double LinearSigmaCombiner::W ( const Result r) const
inlinevirtual

Calculate the weight

\[ w = 1/2 (s + x s')^3 / s \]

Parameters
rObservation
Returns
\( W\)

Implements Combiner.

Definition at line 478 of file Combiner.C.

static double LinearSigmaCombiner::WrapL ( double *  xp,
double *  pp 
)
inlinestatic

Wrap likely-hood function for ROOT

Parameters
xpPointer to independent variables
ppPointer to parameters
Returns
Likely-hood function evaluate at xp

Definition at line 563 of file Combiner.C.

Referenced by DrawResult::MakeF().


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