A set of TF1 linear sum of base functions (Gaussians) More...

#include <GausFitCache.h>

Inheritance diagram for hit::GausFitCache:

Public Member Functions
	GausFitCache (std::string new_name="GausFitCache")
	Constructor; optionally set the name of the repository. More...

virtual	~GausFitCache ()
	Destructor. More...

std::string	GetName () const
	Return the name of this cache. More...

virtual TF1 *	Get (size_t nFunc)
	Returns a function sum of nFunc base functions. More...

virtual TF1 *	GetClone (size_t nGaus)

virtual std::string	FunctionName (size_t nFunc) const
	Returns a name for the function with nFunc base functions. More...

Protected Member Functions
virtual TF1 *	CreateFunction (size_t nFunc) const
	Creates a new sum function. More...

Protected Attributes
std::string	name
	name of the cache More...

std::vector< TF1 * >	funcs

Detailed Description

A set of TF1 linear sum of base functions (Gaussians)

This object holds and owns a number of functions that are linear sum of "base" functions. The original use is for Gaussian functions, and this class implements Gaussians as base functions. This class is used as a base class for other function caches that do not necessarily use Gaussian base functions.

The idea is that if you need a temporary function to perform a fit and extract the parameters, you can reuse the same function over and over rather than creating a new one each time.

The expected use for an algorithm is to have one of these caches as a data member and when the algorithm code needs a function it obtains it with:

TF1* pFunc = fitcache.Get(nGaussians);

Then pFunc is used for fitting but never destroyed.

Definition at line 46 of file GausFitCache.h.

Constructor & Destructor Documentation

hit::GausFitCache::GausFitCache ( std::string new_name = "GausFitCache" )

inline

Constructor; optionally set the name of the repository.

Definition at line 49 of file GausFitCache.h.

49 : name(new_name) {}

hit::GausFitCache::name

std::string name

name of the cache

Definition: GausFitCache.h:79

hit::GausFitCache::~GausFitCache ( )

virtual

Destructor.

Definition at line 36 of file GausFitCache.cxx.

                               {
     std::for_each
       (funcs.begin(), funcs.end(), std::default_delete<TF1>());
   } // GausFitCache::~GausFitCache()

Member Function Documentation

TF1 * hit::GausFitCache::CreateFunction ( size_t nFunc ) const

protectedvirtual

Creates a new sum function.

Reimplemented in hit::CompiledTruncatedGausFitCache< MaxGaus, CutOff >, hit::CompiledGausFitCache< MaxGaus >, and reco_tool::BaselinedGausFitCache.

Definition at line 62 of file GausFitCache.cxx.

                                                       {
 
     std::string func_name = FunctionName(nFunc);
 
     // no gaussian, no nothing
     if (nFunc == 0) return new TF1(func_name.c_str(), "0");
 
     std::ostringstream sstr;
     sstr << "gaus(0)";
     for (size_t iGaus = 1; iGaus < nFunc; ++iGaus)
       sstr << " + gaus(" << (iGaus*3) << ")";
 
     // create and return the function
     return new TF1(func_name.c_str(), sstr.str().c_str());
   } // GausFitCache::CreateFunction()

std::string hit::GausFitCache::FunctionName ( size_t nFunc ) const

virtual

Returns a name for the function with nFunc base functions.

Definition at line 80 of file GausFitCache.cxx.

                                                          {
     std::ostringstream sstr;
     sstr << name << "_" << nFunc;
     return sstr.str();
   } // GausFitCache::FunctionName()

TF1 * hit::GausFitCache::Get ( size_t nFunc )

virtual

Returns a function sum of nFunc base functions.

Parameters

nGaus the number of base functions in the function

Returns: a pointer to a TF1 with the required characteristics

The returned function must not be deleted at any time!

This implementation returns a function sum of nFunc Gaussians. The parameters are sorted by Gaussian: first normalization (not the area, but the coefficient), first mean, first sigma, second normalization etc.

Definition at line 43 of file GausFitCache.cxx.

                                      {
 
     // expand the list if needed
     if (nFunc >= funcs.size()) funcs.resize(nFunc + 1, nullptr);
 
     // get the pointer we need...
     TF1*& pFunc = funcs[nFunc];
 
     if (!pFunc) pFunc = CreateFunction(nFunc);
 
     return pFunc;
   } // GausFitCache::Get()