\section{Soft\-Gauss\-Particle\-Constraint Class Reference}
\label{classSoftGaussParticleConstraint}\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}}


Abstract base class for constraints of kinematic fits.  




{\ttfamily \#include $<$Soft\-Gauss\-Particle\-Constraint.\-h$>$}

Inheritance diagram for Soft\-Gauss\-Particle\-Constraint\-:\begin{figure}[H]
\begin{center}
\leavevmode
\includegraphics[height=4.000000cm]{classSoftGaussParticleConstraint}
\end{center}
\end{figure}
\subsection*{Public Member Functions}
\begin{DoxyCompactItemize}
\item 
{\bf Soft\-Gauss\-Particle\-Constraint} (double sigma\-\_\-)
\begin{DoxyCompactList}\small\item\em Creates an empty \doxyref{Soft\-Gauss\-Particle\-Constraint}{p.}{classSoftGaussParticleConstraint} object. \end{DoxyCompactList}\item 
virtual {\bf $\sim$\-Soft\-Gauss\-Particle\-Constraint} ()\label{classSoftGaussParticleConstraint_aef20b27a59535e09c13eb84b8294fb47}

\begin{DoxyCompactList}\small\item\em Virtual destructor. \end{DoxyCompactList}\item 
virtual void {\bf set\-F\-O\-List} (std\-::vector$<$ {\bf Particle\-Fit\-Object} $\ast$ $>$ $\ast$fitobjects\-\_\-)
\begin{DoxyCompactList}\small\item\em Adds several \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} objects to the list. \end{DoxyCompactList}\item 
virtual void {\bf add\-To\-F\-O\-List} ({\bf Particle\-Fit\-Object} \&fitobject, int flag=1)\label{classSoftGaussParticleConstraint_ab53c30b274653a4804cf45bb62119834}

\begin{DoxyCompactList}\small\item\em Adds one \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} objects to the list. \end{DoxyCompactList}\item 
virtual void {\bf reset\-F\-O\-List} ()\label{classSoftGaussParticleConstraint_a3121f4a4e6a76bbba54db736079ee968}

\begin{DoxyCompactList}\small\item\em Resests \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} list. \end{DoxyCompactList}\item 
virtual double {\bf get\-Value} () const =0\label{classSoftGaussParticleConstraint_a54ccf24c261bec7114819a86102a3fc0}

\begin{DoxyCompactList}\small\item\em Returns the value of the constraint function. \end{DoxyCompactList}\item 
virtual double {\bf get\-Chi2} () const \label{classSoftGaussParticleConstraint_a1818f89335f00487d3d861a248b1e962}

\begin{DoxyCompactList}\small\item\em Returns the chi2. \end{DoxyCompactList}\item 
virtual double {\bf get\-Error} () const \label{classSoftGaussParticleConstraint_a374250108c203ef5f687477ec04694fd}

\begin{DoxyCompactList}\small\item\em Returns the error on the value of the constraint. \end{DoxyCompactList}\item 
virtual double {\bf get\-Sigma} () const \label{classSoftGaussParticleConstraint_af2bd4e62d39d6376ca76b9db9b11bafe}

\begin{DoxyCompactList}\small\item\em Returns the sigma. \end{DoxyCompactList}\item 
virtual double {\bf set\-Sigma} (double sigma\-\_\-)
\begin{DoxyCompactList}\small\item\em Sets the sigma. \end{DoxyCompactList}\item 
virtual void {\bf get\-Derivatives} (int idim, double der[$\,$]) const =0
\begin{DoxyCompactList}\small\item\em Get first order derivatives. \end{DoxyCompactList}\item 
virtual void {\bf add2nd\-Derivatives\-To\-Matrix} (double $\ast$M, int idim) const 
\begin{DoxyCompactList}\small\item\em Adds second order derivatives to global covariance matrix M. \end{DoxyCompactList}\item 
virtual void {\bf add\-To\-Global\-Chi2\-Der\-Vector} (double $\ast$y, int idim) const 
\begin{DoxyCompactList}\small\item\em Add derivatives of chi squared to global derivative matrix. \end{DoxyCompactList}\item 
virtual void {\bf invalidate\-Cache} () const \label{classSoftGaussParticleConstraint_a64b410da58cc7a3a748917ca9ddc7349}

\begin{DoxyCompactList}\small\item\em Invalidates any cached values for the next event. \end{DoxyCompactList}\item 
void {\bfseries test1st\-Derivatives} ()\label{classSoftGaussParticleConstraint_a513b8ac1bdf695c7fda1e7cf708a1aac}

\item 
void {\bfseries test2nd\-Derivatives} ()\label{classSoftGaussParticleConstraint_aa4828cd6d62945620cab68f0a8f020df}

\item 
double {\bf num1st\-Derivative} (int ifo, int ilocal, double eps)
\begin{DoxyCompactList}\small\item\em Evaluates numerically the 1st derivative w.\-r.\-t. a parameter. \end{DoxyCompactList}\item 
double {\bf num2nd\-Derivative} (int ifo1, int ilocal1, double eps1, int ifo2, int ilocal2, double eps2)
\begin{DoxyCompactList}\small\item\em Evaluates numerically the 2nd derivative w.\-r.\-t. 2 parameters. \end{DoxyCompactList}\item 
int {\bfseries get\-Var\-Basis} () const \label{classSoftGaussParticleConstraint_abab2f5fe237517cb739ad6a23a8c6a35}

\end{DoxyCompactItemize}
\subsection*{Protected Types}
\begin{DoxyCompactItemize}
\item 
enum \{ {\bfseries V\-A\-R\-\_\-\-B\-A\-S\-I\-S} =Base\-Defs\-:\-:V\-A\-R\-B\-A\-S\-I\-S\-\_\-\-E\-P\-X\-Y\-Z
 \}
\item 
typedef std\-::vector\\*
$<$ {\bf Particle\-Fit\-Object} $\ast$ $>$ {\bf Fit\-Object\-Container}\label{classSoftGaussParticleConstraint_a521a014a4af2009956ea4e5c20b0b3a4}

\begin{DoxyCompactList}\small\item\em Vector of pointers to Particle\-Fit\-Objects. \end{DoxyCompactList}\item 
typedef \\*
Fit\-Object\-Container\-::iterator {\bf Fit\-Object\-Iterator}\label{classSoftGaussParticleConstraint_aa196273dd78f2b0394e28902197427c1}

\begin{DoxyCompactList}\small\item\em Iterator through vector of pointers to Particle\-Fit\-Objects. \end{DoxyCompactList}\item 
typedef \\*
Fit\-Object\-Container\-::const\-\_\-iterator {\bf Const\-Fit\-Object\-Iterator}\label{classSoftGaussParticleConstraint_a10c05f7384c58a9d297575562f42ea84}

\begin{DoxyCompactList}\small\item\em Constant iterator through vector of pointers to Particle\-Fit\-Objects. \end{DoxyCompactList}\end{DoxyCompactItemize}
\subsection*{Protected Member Functions}
\begin{DoxyCompactItemize}
\item 
virtual bool {\bf second\-Derivatives} (int i, int j, double $\ast${\bf derivatives}) const =0
\begin{DoxyCompactList}\small\item\em Second derivatives with respect to the 4-\/vectors of Fit objects i and j; result false if all derivatives are zero. \end{DoxyCompactList}\item 
virtual bool {\bf first\-Derivatives} (int i, double $\ast${\bf derivatives}) const =0
\begin{DoxyCompactList}\small\item\em First derivatives with respect to the 4-\/vector of Fit objects i; result false if all derivatives are zero. \end{DoxyCompactList}\end{DoxyCompactItemize}
\subsection*{Protected Attributes}
\begin{DoxyCompactItemize}
\item 
{\bf Fit\-Object\-Container} {\bf fitobjects}\label{classSoftGaussParticleConstraint_a96ca87443b22956f3d9e7360813eb494}

\begin{DoxyCompactList}\small\item\em The Fit\-Object\-Container. \end{DoxyCompactList}\item 
std\-::vector$<$ double $>$ {\bf derivatives}\label{classSoftGaussParticleConstraint_aea77e1ec38983b92c817daad6b1e42bf}

\begin{DoxyCompactList}\small\item\em The derivatives. \end{DoxyCompactList}\item 
std\-::vector$<$ int $>$ {\bf flags}
\begin{DoxyCompactList}\small\item\em The flags can be used to divide the Fit\-Object\-Container into several subsets used for example to implement an equal mass constraint (see \doxyref{Mass\-Constraint}{p.}{classMassConstraint}). \end{DoxyCompactList}\item 
double {\bf sigma}\label{classSoftGaussParticleConstraint_aa0b65bdb310cc1f0d1323a7053aa4d1b}

\begin{DoxyCompactList}\small\item\em The sigma of the Gaussian. \end{DoxyCompactList}\end{DoxyCompactItemize}
\subsection*{Additional Inherited Members}


\subsection{Detailed Description}
Abstract base class for constraints of kinematic fits. 

This class defines the minimal functionality any constraint class must provide. First of all a constraint should know on with particles (or Fit\-Object) it is applied. Where as for example a constraint on the total transvese momentum takes into account all particles in the event, an invariant mass constraint usually applies only to a subset of particles.

The particle list is implemented as a vector containing pointers to objects derived from \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} and can be either set a whole (set\-F\-O\-List) or enlarged by adding a single \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} (add\-To\-F\-O\-List).

From the four--momenta of all concerned fit objects the constraint has to be able to calculate its current value (get\-Value). Constraints should be formulated such that a value of zero corresponds to a perfectly fulfilled constraint.

In order to find a solution to the constrained minimisation problem, fit algorithms usually need the first order derivatives of the constraint with respect to the fit parameters. Since many constraints can be most easily expressed in terms of E, px, py, pz, the constraints supply their derivatives w.\-r.\-t. these parameters. If a Fit\-Object uses a different parametrisation, it is its own task to provide the additional derivatives of E, px, py, pz w.\-r.\-t. the parameters of the Fit\-Object. Thus it is easily possible to use Fit\-Objects with different kinds of parametrisations under the same constraint. Some fit algorithms also need the second derivatives of the constraint, i.\-e. the Newton\-Fitter.

First and second order derivatives of each constraint can be added directly to the global covariance matrix containing the derivatives of all constraints w.\-r.\-t. to all parameters (add1st\-Derivatives\-To\-Matrix, add2nd\-Derivatives\-To\-Matrix). This requires the constraint to know its position in the overall list of constraints (global\-Num).

Author\-: Jenny List, Benno List \begin{DoxyParagraph}{Date\-:}
2008/02/13 12\-:37\-:38 
\end{DoxyParagraph}
\begin{DoxyParagraph}{Author\-:}
blist 
\end{DoxyParagraph}


\subsection{Constructor \& Destructor Documentation}
\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}}
\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{Soft\-Gauss\-Particle\-Constraint}]{\setlength{\rightskip}{0pt plus 5cm}Soft\-Gauss\-Particle\-Constraint\-::\-Soft\-Gauss\-Particle\-Constraint (
\begin{DoxyParamCaption}
\item[{double}]{sigma\-\_\-}
\end{DoxyParamCaption}
)}\label{classSoftGaussParticleConstraint_aa40610dfc3c99422d56c3851630a43d0}


Creates an empty \doxyref{Soft\-Gauss\-Particle\-Constraint}{p.}{classSoftGaussParticleConstraint} object. 


\begin{DoxyParams}{Parameters}
{\em sigma\-\_\-} & The sigma value \\
\hline
\end{DoxyParams}


References invalidate\-Cache().



\subsection{Member Function Documentation}
\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!add2nd\-Derivatives\-To\-Matrix@{add2nd\-Derivatives\-To\-Matrix}}
\index{add2nd\-Derivatives\-To\-Matrix@{add2nd\-Derivatives\-To\-Matrix}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{add2nd\-Derivatives\-To\-Matrix}]{\setlength{\rightskip}{0pt plus 5cm}void Soft\-Gauss\-Particle\-Constraint\-::add2nd\-Derivatives\-To\-Matrix (
\begin{DoxyParamCaption}
\item[{double $\ast$}]{M, }
\item[{int}]{idim}
\end{DoxyParamCaption}
) const\hspace{0.3cm}{\ttfamily [virtual]}}\label{classSoftGaussParticleConstraint_a7b0bc6dff3540d72aba7e2ad44b90868}


Adds second order derivatives to global covariance matrix M. 

Calculates the second derivative of the constraint g w.\-r.\-t.

the various parameters and adds it to the global covariance matrix

We denote with P\-\_\-i the 4-\/vector of the i-\/th \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject}, then \$\$ \{ $^\wedge$2 g\}\{ a\-\_\-k  a\-\_\-l\} =   \{ $^\wedge$2 g\}\{ P\-\_\-i  P\-\_\-j\}  \{ P\-\_\-i\}\{ a\-\_\-k\}  \{ P\-\_\-j\}\{ a\-\_\-l\}
\begin{DoxyItemize}
\item \{ g\}\{ P\-\_\-i\}  \{$^\wedge$2 P\-\_\-i\}\{ a\-\_\-k  a\-\_\-l\} \$\$ Here, \$\{ P\-\_\-i\}\{ a\-\_\-k\}\$ is a \$4  n\-\_\-i\$ Matrix, where \$n\-\_\-i\$ is the number of parameters of Fit\-Object i; Correspondingly, \$\{$^\wedge$2 P\-\_\-i\}\{ a\-\_\-k  a\-\_\-l\}\$ is a \$4  n\-\_\-i  n\-\_\-i\$ matrix. Also, \$\{ $^\wedge$2 g\}\{ P\-\_\-i  P\-\_\-j\}\$ is a \$4 4\$ matrix for a given i and j, and \$\{ g\}\{ P\-\_\-i\}\$ is a 4-\/vector (though not a Lorentz-\/vector!). 
\end{DoxyItemize}First, treat the part \$\$ \{ $^\wedge$2 g\}\{ P\-\_\-i  P\-\_\-j\}  \{ P\-\_\-i\}\{ a\-\_\-k\}  \{ P\-\_\-j\}\{ a\-\_\-l\} \$\$

Second, treat the parts \$\$  \{ g\}\{ P\-\_\-i\}  \{$^\wedge$2 P\-\_\-i\}\{ a\-\_\-k  a\-\_\-l\} \$\$ and \$\$ \{$^\wedge$2 h\}\{ g$^\wedge$2\}  \{ g\}\{ P\-\_\-i\}  \{ P\-\_\-i\}\{ a\-\_\-k\}  \{ g\}\{ P\-\_\-j\}  \{ P\-\_\-j\}\{ a\-\_\-l\} \$\$

Here, \$\{ g\}\{ P\-\_\-i\}\$ is a 4-\/vector, which we pass on to the Fit\-Object
\begin{DoxyParams}{Parameters}
{\em M} & Covariance matrix, at least idim x idim \\
\hline
{\em idim} & First dimension of the array \\
\hline
\end{DoxyParams}


Implements {\bf Base\-Soft\-Constraint} \doxyref{}{p.}{classBaseSoftConstraint_a5b7a928b4b725f9cb4259672235af9fb}.



References Base\-Fit\-Object\-::add\-To\-Global\-Chi2\-Der\-Vector(), first\-Derivatives(), fitobjects, Base\-Fit\-Object\-::get\-Global\-Par\-Num(), Base\-Fit\-Object\-::get\-N\-Par(), get\-Sigma(), get\-Value(), and second\-Derivatives().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!add\-To\-Global\-Chi2\-Der\-Vector@{add\-To\-Global\-Chi2\-Der\-Vector}}
\index{add\-To\-Global\-Chi2\-Der\-Vector@{add\-To\-Global\-Chi2\-Der\-Vector}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{add\-To\-Global\-Chi2\-Der\-Vector}]{\setlength{\rightskip}{0pt plus 5cm}void Soft\-Gauss\-Particle\-Constraint\-::add\-To\-Global\-Chi2\-Der\-Vector (
\begin{DoxyParamCaption}
\item[{double $\ast$}]{y, }
\item[{int}]{idim}
\end{DoxyParamCaption}
) const\hspace{0.3cm}{\ttfamily [virtual]}}\label{classSoftGaussParticleConstraint_a0fabfd14becaa7c75384248c9ae67ba5}


Add derivatives of chi squared to global derivative matrix. 


\begin{DoxyParams}{Parameters}
{\em y} & Vector of chi2 derivatives \\
\hline
{\em idim} & Vector size \\
\hline
\end{DoxyParams}


Implements {\bf Base\-Soft\-Constraint} \doxyref{}{p.}{classBaseSoftConstraint_ac031591b5bcf52ab7acda7c643714d44}.



References Base\-Fit\-Object\-::add\-To\-Global\-Chi2\-Der\-Vector(), first\-Derivatives(), fitobjects, get\-Sigma(), and get\-Value().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!first\-Derivatives@{first\-Derivatives}}
\index{first\-Derivatives@{first\-Derivatives}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{first\-Derivatives}]{\setlength{\rightskip}{0pt plus 5cm}virtual bool Soft\-Gauss\-Particle\-Constraint\-::first\-Derivatives (
\begin{DoxyParamCaption}
\item[{int}]{i, }
\item[{double $\ast$}]{derivatives}
\end{DoxyParamCaption}
) const\hspace{0.3cm}{\ttfamily [protected]}, {\ttfamily [pure virtual]}}\label{classSoftGaussParticleConstraint_a08e956b0334a8a221deb6e771ffcb0aa}


First derivatives with respect to the 4-\/vector of Fit objects i; result false if all derivatives are zero. 


\begin{DoxyParams}{Parameters}
{\em i} & number of 1st Fit\-Object \\
\hline
{\em derivatives} & The result 4-\/vector \\
\hline
\end{DoxyParams}


Implemented in {\bf Soft\-Gauss\-Mass\-Constraint} \doxyref{}{p.}{classSoftGaussMassConstraint_a9102ce05ef5d4614d7233680ff0e7086}, and {\bf Soft\-Gauss\-Momentum\-Constraint} \doxyref{}{p.}{classSoftGaussMomentumConstraint_a10a1f073d36bbdb11ff8e68e14dfa40e}.



Referenced by add2nd\-Derivatives\-To\-Matrix(), add\-To\-Global\-Chi2\-Der\-Vector(), and get\-Error().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!get\-Derivatives@{get\-Derivatives}}
\index{get\-Derivatives@{get\-Derivatives}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{get\-Derivatives}]{\setlength{\rightskip}{0pt plus 5cm}virtual void Soft\-Gauss\-Particle\-Constraint\-::get\-Derivatives (
\begin{DoxyParamCaption}
\item[{int}]{idim, }
\item[{double}]{der[$\,$]}
\end{DoxyParamCaption}
) const\hspace{0.3cm}{\ttfamily [pure virtual]}}\label{classSoftGaussParticleConstraint_a466338d7f4d153acc03a4d35b93a596b}


Get first order derivatives. 

Call this with a predefined array \char`\"{}der\char`\"{} with the necessary number of entries! 
\begin{DoxyParams}{Parameters}
{\em idim} & First dimension of the array \\
\hline
{\em der} & Array of derivatives, at least idim x idim \\
\hline
\end{DoxyParams}


Implements {\bf Base\-Constraint} \doxyref{}{p.}{classBaseConstraint_a01d60bff974a2926521838c640373d7f}.



Implemented in {\bf Soft\-Gauss\-Mass\-Constraint} \doxyref{}{p.}{classSoftGaussMassConstraint_a21fb08382c0034f18f62b248fcf6e551}, and {\bf Soft\-Gauss\-Momentum\-Constraint} \doxyref{}{p.}{classSoftGaussMomentumConstraint_ac3dbdb446e35bf230f7dc805c9cee73f}.

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!num1st\-Derivative@{num1st\-Derivative}}
\index{num1st\-Derivative@{num1st\-Derivative}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{num1st\-Derivative}]{\setlength{\rightskip}{0pt plus 5cm}double Soft\-Gauss\-Particle\-Constraint\-::num1st\-Derivative (
\begin{DoxyParamCaption}
\item[{int}]{ifo, }
\item[{int}]{ilocal, }
\item[{double}]{eps}
\end{DoxyParamCaption}
)}\label{classSoftGaussParticleConstraint_a344b9634223246e8fba6a788a8bce3d6}


Evaluates numerically the 1st derivative w.\-r.\-t. a parameter. 


\begin{DoxyParams}{Parameters}
{\em ifo} & Number of Fit\-Object \\
\hline
{\em ilocal} & Local parameter number \\
\hline
{\em eps} & variation of local parameter \\
\hline
\end{DoxyParams}


References fitobjects, get\-Chi2(), Base\-Fit\-Object\-::get\-Param(), and Base\-Fit\-Object\-::set\-Param().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!num2nd\-Derivative@{num2nd\-Derivative}}
\index{num2nd\-Derivative@{num2nd\-Derivative}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{num2nd\-Derivative}]{\setlength{\rightskip}{0pt plus 5cm}double Soft\-Gauss\-Particle\-Constraint\-::num2nd\-Derivative (
\begin{DoxyParamCaption}
\item[{int}]{ifo1, }
\item[{int}]{ilocal1, }
\item[{double}]{eps1, }
\item[{int}]{ifo2, }
\item[{int}]{ilocal2, }
\item[{double}]{eps2}
\end{DoxyParamCaption}
)}\label{classSoftGaussParticleConstraint_a90e3395a4fe9697a3c82ed894d5e4e59}


Evaluates numerically the 2nd derivative w.\-r.\-t. 2 parameters. 


\begin{DoxyParams}{Parameters}
{\em ifo1} & Number of 1st Fit\-Object \\
\hline
{\em ilocal1} & 1st local parameter number \\
\hline
{\em eps1} & variation of 1st local parameter \\
\hline
{\em ifo2} & Number of 1st Fit\-Object \\
\hline
{\em ilocal2} & 1st local parameter number \\
\hline
{\em eps2} & variation of 2nd local parameter \\
\hline
\end{DoxyParams}


References fitobjects, get\-Chi2(), Base\-Fit\-Object\-::get\-Param(), and Base\-Fit\-Object\-::set\-Param().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!second\-Derivatives@{second\-Derivatives}}
\index{second\-Derivatives@{second\-Derivatives}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{second\-Derivatives}]{\setlength{\rightskip}{0pt plus 5cm}virtual bool Soft\-Gauss\-Particle\-Constraint\-::second\-Derivatives (
\begin{DoxyParamCaption}
\item[{int}]{i, }
\item[{int}]{j, }
\item[{double $\ast$}]{derivatives}
\end{DoxyParamCaption}
) const\hspace{0.3cm}{\ttfamily [protected]}, {\ttfamily [pure virtual]}}\label{classSoftGaussParticleConstraint_ac8fb61123f71e58634acd87a22c805bd}


Second derivatives with respect to the 4-\/vectors of Fit objects i and j; result false if all derivatives are zero. 


\begin{DoxyParams}{Parameters}
{\em i} & number of 1st Fit\-Object \\
\hline
{\em j} & number of 2nd Fit\-Object \\
\hline
{\em derivatives} & The result 4x4 matrix \\
\hline
\end{DoxyParams}


Implemented in {\bf Soft\-Gauss\-Mass\-Constraint} \doxyref{}{p.}{classSoftGaussMassConstraint_a6452d3f7e37e167615e1a57d334cba3b}, and {\bf Soft\-Gauss\-Momentum\-Constraint} \doxyref{}{p.}{classSoftGaussMomentumConstraint_abbfb7024a4959d4dc044dcf7f1cf5c2c}.



Referenced by add2nd\-Derivatives\-To\-Matrix().

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!set\-F\-O\-List@{set\-F\-O\-List}}
\index{set\-F\-O\-List@{set\-F\-O\-List}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{set\-F\-O\-List}]{\setlength{\rightskip}{0pt plus 5cm}virtual void Soft\-Gauss\-Particle\-Constraint\-::set\-F\-O\-List (
\begin{DoxyParamCaption}
\item[{std\-::vector$<$ {\bf Particle\-Fit\-Object} $\ast$ $>$ $\ast$}]{fitobjects\-\_\-}
\end{DoxyParamCaption}
)\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [virtual]}}\label{classSoftGaussParticleConstraint_a7c3fe0c9a8eb1f2e184b3ee654d64e9d}


Adds several \doxyref{Particle\-Fit\-Object}{p.}{classParticleFitObject} objects to the list. 


\begin{DoxyParams}{Parameters}
{\em fitobjects\-\_\-} & A list of \doxyref{Base\-Fit\-Object}{p.}{classBaseFitObject} objects \\
\hline
\end{DoxyParams}


References fitobjects, and flags.

\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!set\-Sigma@{set\-Sigma}}
\index{set\-Sigma@{set\-Sigma}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{set\-Sigma}]{\setlength{\rightskip}{0pt plus 5cm}double Soft\-Gauss\-Particle\-Constraint\-::set\-Sigma (
\begin{DoxyParamCaption}
\item[{double}]{sigma\-\_\-}
\end{DoxyParamCaption}
)\hspace{0.3cm}{\ttfamily [virtual]}}\label{classSoftGaussParticleConstraint_a4513d29b375c757d1b7e0662eb671444}


Sets the sigma. 


\begin{DoxyParams}{Parameters}
{\em sigma\-\_\-} & The new sigma value \\
\hline
\end{DoxyParams}


References sigma.



\subsection{Member Data Documentation}
\index{Soft\-Gauss\-Particle\-Constraint@{Soft\-Gauss\-Particle\-Constraint}!flags@{flags}}
\index{flags@{flags}!SoftGaussParticleConstraint@{Soft\-Gauss\-Particle\-Constraint}}
\subsubsection[{flags}]{\setlength{\rightskip}{0pt plus 5cm}std\-::vector$<$int$>$ Soft\-Gauss\-Particle\-Constraint\-::flags\hspace{0.3cm}{\ttfamily [protected]}}\label{classSoftGaussParticleConstraint_afc2aec889aaa3cf3f6d327698a8d7152}


The flags can be used to divide the Fit\-Object\-Container into several subsets used for example to implement an equal mass constraint (see \doxyref{Mass\-Constraint}{p.}{classMassConstraint}). 



Referenced by add\-To\-F\-O\-List(), Soft\-Gauss\-Mass\-Constraint\-::first\-Derivatives(), Soft\-Gauss\-Mass\-Constraint\-::get\-Derivatives(), Soft\-Gauss\-Mass\-Constraint\-::get\-Mass(), Soft\-Gauss\-Mass\-Constraint\-::get\-Value(), reset\-F\-O\-List(), Soft\-Gauss\-Mass\-Constraint\-::second\-Derivatives(), and set\-F\-O\-List().



The documentation for this class was generated from the following files\-:\begin{DoxyCompactItemize}
\item 
{\bf Soft\-Gauss\-Particle\-Constraint.\-h}\item 
{\bf Soft\-Gauss\-Particle\-Constraint.\-cc}\end{DoxyCompactItemize}
