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SoftGaussMassConstraint Class Reference

Implements constraint 0 = mass1 - mass2 - m. More...

#include <SoftGaussMassConstraint.h>

Inheritance diagram for SoftGaussMassConstraint:
Collaboration diagram for SoftGaussMassConstraint:

Public Member Functions

 SoftGaussMassConstraint (double sigma_, double mass_=0.)
 Constructor. More...
 
virtual ~SoftGaussMassConstraint ()
 Virtual destructor.
 
virtual double getValue () const override
 Returns the value of the constraint function.
 
virtual void getDerivatives (int idim, double der[]) const override
 Get first order derivatives. More...
 
virtual double getMass (int flag=1)
 Get the actual invariant mass of the fit objects with a given flag. More...
 
virtual void setMass (double mass_)
 Sets the target mass of the constraint. More...
 
virtual void setFOList (std::vector< ParticleFitObject * > *fitobjects_)
 Adds several ParticleFitObject objects to the list. More...
 
virtual void addToFOList (ParticleFitObject &fitobject, int flag=1)
 Adds one ParticleFitObject objects to the list.
 
virtual void resetFOList ()
 Resests ParticleFitObject list.
 
virtual double getChi2 () const override
 Returns the chi2.
 
virtual double getError () const override
 Returns the error on the value of the constraint.
 
virtual double getSigma () const
 Returns the sigma.
 
virtual double setSigma (double sigma_)
 Sets the sigma. More...
 
virtual void add2ndDerivativesToMatrix (double *M, int idim) const override
 Adds second order derivatives to global covariance matrix M. More...
 
virtual void addToGlobalChi2DerVector (double *y, int idim) const override
 Add derivatives of chi squared to global derivative matrix. More...
 
void invalidateCache () const
 Invalidates any cached values for the next event.
 
void test1stDerivatives ()
 
void test2ndDerivatives ()
 
double num1stDerivative (int ifo, int ilocal, double eps)
 Evaluates numerically the 1st derivative w.r.t. a parameter. More...
 
double num2ndDerivative (int ifo1, int ilocal1, double eps1, int ifo2, int ilocal2, double eps2)
 Evaluates numerically the 2nd derivative w.r.t. 2 parameters. More...
 
int getVarBasis () const
 
virtual const char * getName () const
 Returns the name of the constraint.
 
void setName (const char *name_)
 Set object's name.
 
virtual std::ostream & print (std::ostream &os) const
 print object to ostream More...
 

Protected Types

enum  { VAR_BASIS = BaseDefs::VARBASIS_EPXYZ }
 
typedef std::vector< ParticleFitObject * > FitObjectContainer
 Vector of pointers to ParticleFitObjects.
 
typedef FitObjectContainer::iterator FitObjectIterator
 Iterator through vector of pointers to ParticleFitObjects.
 
typedef FitObjectContainer::const_iterator ConstFitObjectIterator
 Constant iterator through vector of pointers to ParticleFitObjects.
 

Protected Member Functions

virtual bool secondDerivatives (int i, int j, double *derivatives) const override
 Second derivatives with respect to the 4-vectors of Fit objects i and j; result false if all derivatives are zero. More...
 
virtual bool firstDerivatives (int i, double *derivatives) const override
 First derivatives with respect to the 4-vector of Fit objects i; result false if all derivatives are zero. More...
 

Protected Attributes

double mass
 The mass difference between object sets 1 and 2.
 
FitObjectContainer fitobjects
 The FitObjectContainer.
 
std::vector< double > derivatives
 The derivatives.
 
std::vector< int > flags
 The flags can be used to divide the FitObjectContainer into several subsets used for example to implement an equal mass constraint (see MassConstraint).
 
double sigma
 The sigma of the Gaussian.
 
char * name
 

Related Functions

(Note that these are not member functions.)

std::ostream & operator<< (std::ostream &os, const BaseConstraint &bc)
 Prints out a BaseConstraint, using its print method. More...
 

Detailed Description

Implements constraint 0 = mass1 - mass2 - m.

This class implements different mass constraints:

  • the invariant mass of several objects should be m
  • the difference of the invariant masses between two sets of objects should be m (normally m=0 in this case).

Author: Jenny List, Benno List Last update:

Date
2008/02/12 16:43:26

by:

Author
blist

Definition at line 45 of file SoftGaussMassConstraint.h.

Constructor & Destructor Documentation

◆ SoftGaussMassConstraint()

SoftGaussMassConstraint ( double  sigma_,
double  mass_ = 0. 
)
explicit

Constructor.

Parameters
sigma_The sigma value
mass_The mass difference between object sets 1 and 2

Definition at line 35 of file SoftGaussMassConstraint.cc.

37  mass(mass_)
38  {}
double mass
The mass difference between object sets 1 and 2.
SoftGaussParticleConstraint(double sigma_)
Creates an empty SoftGaussParticleConstraint object.

Member Function Documentation

◆ add2ndDerivativesToMatrix()

void add2ndDerivativesToMatrix ( double *  M,
int  idim 
) const
overridevirtualinherited

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 ParticleFitObject, then

\[ \frac{\partial ^2 g}{\partial a_k \partial a_l} = \sum_i \sum_j \frac{\partial ^2 g}{\partial P_i \partial P_j} \cdot \frac{\partial P_i}{\partial a_k} \cdot \frac{\partial P_j}{\partial a_l} + \sum_i \frac{\partial g}{\partial P_i} \cdot \frac{\partial^2 P_i}{\partial a_k \partial a_l} \]

Here, $\frac{\partial P_i}{\partial a_k}$ is a $4 \times n_i$ Matrix, where $n_i$ is the number of parameters of FitObject i; Correspondingly, $\frac{\partial^2 P_i}{\partial a_k \partial a_l}$ is a $4 \times n_i \times n_i$ matrix. Also, $\frac{\partial ^2 g}{\partial P_i \partial P_j}$ is a $4\times 4$ matrix for a given i and j, and $\frac{\partial g}{\partial P_i}$ is a 4-vector (though not a Lorentz-vector!).

First, treat the part

\[ \frac{\partial ^2 g}{\partial P_i \partial P_j} \cdot \frac{\partial P_i}{\partial a_k} \cdot \frac{\partial P_j}{\partial a_l} \]

Second, treat the parts

\[ \sum_i \frac{\partial g}{\partial P_i} \cdot \frac{\partial^2 P_i}{\partial a_k \partial a_l} \]

and

\[ \frac{\partial^2 h}{\partial g^2} \sum_i \frac{\partial g}{\partial P_i} \cdot \frac{\partial P_i}{\partial a_k} \sum_j \frac{\partial g}{\partial P_j} \cdot \frac{\partial P_j}{\partial a_l} \]

Here, $\frac{\partial g}{\partial P_i}$ is a 4-vector, which we pass on to the FitObject

Parameters
MCovariance matrix, at least idim x idim
idimFirst dimension of the array

Implements BaseSoftConstraint.

Definition at line 92 of file SoftGaussParticleConstraint.cc.

93  {
94 
101  double s = getSigma();
102  double fact = 2 * getValue() / (s * s);
103 
104  // Derivatives \f$\frac{\partial ^2 g}{\partial P_i \partial P_j}\f$ at fixed i, j
105  // d2GdPidPj[4*ii+jj] is derivative w.r.t. P_i,ii and P_j,jj, where ii=0,1,2,3 for E,px,py,pz
106  double d2GdPidPj[16];
107  // Derivatives \f$\frac {\partial P_i}{\partial a_k}\f$ for all i;
108  // k is local parameter number
109  // dPidAk[KMAX*4*i + 4*k + ii] is \f$\frac {\partial P_{i,ii}}{\partial a_k}\f$,
110  // with ii=0, 1, 2, 3 for E, px, py, pz
111  const int KMAX = 4;
112  const int n = fitobjects.size();
113  auto* dPidAk = new double[n * KMAX * 4];
114  bool* dPidAkval = new bool[n];
115 
116  for (int i = 0; i < n; ++i) dPidAkval[i] = false;
117 
118  // Derivatives \f$\frac{\partial ^2 g}{\partial P_i \partial a_l}\f$ at fixed i
119  // d2GdPdAl[4*l + ii] is \f$\frac{\partial ^2 g}{\partial P_{i,ii} \partial a_l}\f$
120  double d2GdPdAl[4 * KMAX];
121  // Derivatives \f$\frac{\partial ^2 g}{\partial a_k \partial a_l}\f$
122  double d2GdAkdAl[KMAX * KMAX] = {0};
123 
124  // Global parameter numbers: parglobal[KMAX*i+klocal]
125  // is global parameter number of local parameter klocal of i-th Fit object
126  int* parglobal = new int[KMAX * n];
127 
128  for (int i = 0; i < n; ++i) {
129  const ParticleFitObject* foi = fitobjects[i];
130  assert(foi);
131  for (int klocal = 0; klocal < foi->getNPar(); ++klocal) {
132  parglobal [KMAX * i + klocal] = foi->getGlobalParNum(klocal);
133  }
134  }
135 
136 
137  for (int i = 0; i < n; ++i) {
138  const ParticleFitObject* foi = fitobjects[i];
139  assert(foi);
140  for (int j = 0; j < n; ++j) {
141  const ParticleFitObject* foj = fitobjects[j];
142  assert(foj);
143  if (secondDerivatives(i, j, d2GdPidPj)) {
144  if (!dPidAkval[i]) {
145  foi->getDerivatives(dPidAk + i * (KMAX * 4), KMAX * 4);
146  dPidAkval[i] = true;
147  }
148  if (!dPidAkval[j]) {
149  foj->getDerivatives(dPidAk + j * (KMAX * 4), KMAX * 4);
150  dPidAkval[j] = true;
151  }
152  // Now sum over E/px/Py/Pz for object j:
153  // \f[
154  // \frac{\partial ^2 g}{\partial P_{i,ii} \partial a_l}
155  // = (sum_{j}) sum_{jj} frac{\partial ^2 g}{\partial P_{i,ii} \partial P_{j,jj}}
156  // \cdot \frac{\partial P_{j,jj}}{\partial a_l}
157  // \f]
158  // We're summing over jj here
159  for (int llocal = 0; llocal < foj->getNPar(); ++llocal) {
160  for (int ii = 0; ii < 4; ++ii) {
161  int ind1 = 4 * ii;
162  int ind2 = (KMAX * 4) * j + 4 * llocal;
163  double& r = d2GdPdAl[4 * llocal + ii];
164  r = d2GdPidPj[ ind1] * dPidAk[ ind2]; // E
165  r += d2GdPidPj[++ind1] * dPidAk[++ind2]; // px
166  r += d2GdPidPj[++ind1] * dPidAk[++ind2]; // py
167  r += d2GdPidPj[++ind1] * dPidAk[++ind2]; // pz
168  }
169  }
170  // Now sum over E/px/Py/Pz for object i, i.e. sum over ii:
171  // \f[
172  // \frac{\partial ^2 g}{\partial a_k \partial a_l}
173  // = \sum_{ii} \frac{\partial ^2 g}{\partial P_{i,ii} \partial a_l} \cdot
174  // \frac{\partial P_{i,ii}}{\partial a_k}
175  // \f]
176  for (int klocal = 0; klocal < foi->getNPar(); ++klocal) {
177  for (int llocal = 0; llocal < foj->getNPar(); ++llocal) {
178  int ind1 = 4 * llocal;
179  int ind2 = (KMAX * 4) * i + 4 * klocal;
180  double& r = d2GdAkdAl[KMAX * klocal + llocal];
181  r = d2GdPdAl[ ind1] * dPidAk[ ind2]; //E
182  r += d2GdPdAl[++ind1] * dPidAk[++ind2]; // px
183  r += d2GdPdAl[++ind1] * dPidAk[++ind2]; // py
184  r += d2GdPdAl[++ind1] * dPidAk[++ind2]; // pz
185  }
186  }
187  // Now expand the local parameter numbers to global ones
188  for (int klocal = 0; klocal < foi->getNPar(); ++klocal) {
189  int kglobal = parglobal [KMAX * i + klocal];
190  for (int llocal = 0; llocal < foj->getNPar(); ++llocal) {
191  int lglobal = parglobal [KMAX * j + llocal];
192  M [idim * kglobal + lglobal] += fact * d2GdAkdAl[KMAX * klocal + llocal];
193  }
194  }
195  }
196  }
197  }
216  auto* v = new double[idim];
217  for (int i = 0; i < idim; ++i) v[i] = 0;
218  double sqrtfact2 = sqrt(2.0) / s;
219 
220  double dgdpi[4];
221  for (int i = 0; i < n; ++i) {
222  const ParticleFitObject* foi = fitobjects[i];
223  assert(foi);
224  if (firstDerivatives(i, dgdpi)) {
225  foi->addTo2ndDerivatives(M, idim, fact, dgdpi, getVarBasis());
226  foi->addToGlobalChi2DerVector(v, idim, sqrtfact2, dgdpi, getVarBasis());
227  }
228  }
229 
230  for (int i = 0; i < idim; ++i) {
231  if (double vi = v[i]) {
232  int ioffs = i * idim;
233  for (double* pvj = v; pvj < v + idim; ++pvj) {
234  M[ioffs++] += vi * (*pvj);
235  }
236  }
237  }
238 
239 
240  delete[] dPidAk;
241  delete[] dPidAkval;
242  delete[] parglobal;
243  delete[] v;
244  }
virtual double getValue() const override=0
Returns the value of the constraint function.
FitObjectContainer fitobjects
The FitObjectContainer.
virtual bool secondDerivatives(int i, int j, double *derivatives) const =0
Second derivatives with respect to the 4-vectors of Fit objects i and j; result false if all derivati...
virtual bool firstDerivatives(int i, double *derivatives) const =0
First derivatives with respect to the 4-vector of Fit objects i; result false if all derivatives are ...
virtual double getSigma() const
Returns the sigma.

◆ addToGlobalChi2DerVector()

void addToGlobalChi2DerVector ( double *  y,
int  idim 
) const
overridevirtualinherited

Add derivatives of chi squared to global derivative matrix.

Parameters
yVector of chi2 derivatives
idimVector size

Implements BaseSoftConstraint.

Definition at line 246 of file SoftGaussParticleConstraint.cc.

◆ firstDerivatives()

bool firstDerivatives ( int  i,
double *  derivatives 
) const
overrideprotectedvirtual

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

Parameters
inumber of 1st FitObject
derivativesThe result 4-vector

Implements SoftGaussParticleConstraint.

Definition at line 191 of file SoftGaussMassConstraint.cc.

◆ getDerivatives()

void getDerivatives ( int  idim,
double  der[] 
) const
overridevirtual

Get first order derivatives.

Call this with a predefined array "der" with the necessary number of entries!

Parameters
idimFirst dimension of the array
derArray of derivatives, at least idim x idim

Implements SoftGaussParticleConstraint.

Definition at line 68 of file SoftGaussMassConstraint.cc.

◆ getMass()

double getMass ( int  flag = 1)
virtual

Get the actual invariant mass of the fit objects with a given flag.

Parameters
flagThe flag

Definition at line 123 of file SoftGaussMassConstraint.cc.

◆ num1stDerivative()

double num1stDerivative ( int  ifo,
int  ilocal,
double  eps 
)
inherited

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

Parameters
ifoNumber of FitObject
ilocalLocal parameter number
epsvariation of local parameter

Definition at line 315 of file SoftGaussParticleConstraint.cc.

◆ num2ndDerivative()

double num2ndDerivative ( int  ifo1,
int  ilocal1,
double  eps1,
int  ifo2,
int  ilocal2,
double  eps2 
)
inherited

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

Parameters
ifo1Number of 1st FitObject
ilocal11st local parameter number
eps1variation of 1st local parameter
ifo2Number of 1st FitObject
ilocal21st local parameter number
eps2variation of 2nd local parameter

Definition at line 329 of file SoftGaussParticleConstraint.cc.

◆ print()

std::ostream & print ( std::ostream &  os) const
virtualinherited

print object to ostream

Parameters
osThe output stream

Definition at line 76 of file BaseConstraint.cc.

◆ secondDerivatives()

bool secondDerivatives ( int  i,
int  j,
double *  derivatives 
) const
overrideprotectedvirtual

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

Parameters
inumber of 1st FitObject
jnumber of 2nd FitObject
derivativesThe result 4x4 matrix

Implements SoftGaussParticleConstraint.

Definition at line 145 of file SoftGaussMassConstraint.cc.

◆ setFOList()

virtual void setFOList ( std::vector< ParticleFitObject * > *  fitobjects_)
inlinevirtualinherited

Adds several ParticleFitObject objects to the list.

Parameters
fitobjects_A list of BaseFitObject objects

Definition at line 83 of file SoftGaussParticleConstraint.h.

85  {
86  for (int i = 0; i < (int) fitobjects_->size(); i++) {
87  fitobjects.push_back((*fitobjects_)[i]);
88  flags.push_back(1);
89  }
90  };
std::vector< int > flags
The flags can be used to divide the FitObjectContainer into several subsets used for example to imple...

◆ setMass()

void setMass ( double  mass_)
virtual

Sets the target mass of the constraint.

Parameters
mass_The new mass

Definition at line 140 of file SoftGaussMassConstraint.cc.

◆ setSigma()

double setSigma ( double  sigma_)
virtualinherited

Sets the sigma.

Parameters
sigma_The new sigma value

Definition at line 42 of file SoftGaussParticleConstraint.cc.

Friends And Related Function Documentation

◆ operator<<()

std::ostream & operator<< ( std::ostream &  os,
const BaseConstraint bc 
)
related

Prints out a BaseConstraint, using its print method.

Parameters
osThe output stream
bcThe object to print

Definition at line 114 of file BaseConstraint.h.


The documentation for this class was generated from the following files: