Inheritance diagram for SiPixelLorentzAngleCalibration:

Public Member Functions
virtual void	beginOfJob (AlignableTracker tracker, AlignableMuon muon, AlignableExtras *extras)

virtual unsigned int	derivatives (std::vector< ValuesIndexPair > &outDerivInds, const TransientTrackingRecHit &hit, const TrajectoryStateOnSurface &tsos, const edm::EventSetup &setup, const EventInfo &eventInfo) const

virtual void	endOfJob ()

virtual double	getParameter (unsigned int index) const

virtual double	getParameterError (unsigned int index) const

virtual unsigned int	numParameters () const
	How many parameters does this calibration define? More...

virtual bool	setParameter (unsigned int index, double value)

virtual bool	setParameterError (unsigned int index, double error)

	SiPixelLorentzAngleCalibration (const edm::ParameterSet &cfg)
	Constructor. More...

virtual	~SiPixelLorentzAngleCalibration ()
	Destructor. More...

Public Member Functions inherited from IntegratedCalibrationBase
virtual std::vector< Values >	derivatives (const TransientTrackingRecHit &hit, const TrajectoryStateOnSurface &tsos, const edm::EventSetup &setup, const EventInfo &eventInfo) const

virtual void	endOfLoop ()

	IntegratedCalibrationBase (const edm::ParameterSet &cfg)
	Values and their parameter index. More...

const std::string &	name () const
	name of this calibration More...

virtual void	startNewLoop ()

virtual	~IntegratedCalibrationBase ()
	Destructor. More...

Private Member Functions
bool	checkLorentzAngleInput (const edm::EventSetup &setup, const EventInfo &eventInfo)

SiPixelLorentzAngle *	createFromTree (const char fileName, const char treeName) const

const SiPixelLorentzAngle *	getLorentzAnglesInput ()

double	getParameterForDetId (unsigned int detId, edm::RunNumber_t run) const

void	writeTree (const SiPixelLorentzAngle lorentzAngle, const std::map< unsigned int, TreeStruct > &treeInfo, const char treeName) const

Private Attributes
const std::vector< std::string >	mergeFileNames_

const edm::ParameterSet	moduleGroupSelCfg_

TkModuleGroupSelector *	moduleGroupSelector_

const std::string	outFileName_

std::vector< double >	parameters_

std::vector< double >	paramUncertainties_

const std::string	recordNameDBwrite_

const bool	saveToDB_

SiPixelLorentzAngle *	siPixelLorentzAngleInput_

edm::ESWatcher < SiPixelLorentzAngleRcd >	watchLorentzAngleRcd_

Additional Inherited Members
Public Types inherited from IntegratedCalibrationBase
typedef AlignmentAlgorithmBase::EventInfo	EventInfo

typedef std::pair< double, double >	Values

typedef std::pair< Values, unsigned int >	ValuesIndexPair
	x- and y-values More...

Detailed Description

Calibration of Lorentz angle for the pixel, integrated in the alignment algorithms.

Note that not all algorithms support this...

Author: : Gero Flucke date : September 2012

Revision:: 1.6

Date:: 2013/05/31 12:13:40

(last update by

Author:: flucke

)

Definition at line 54 of file SiPixelLorentzAngleCalibration.cc.

Constructor & Destructor Documentation

SiPixelLorentzAngleCalibration::SiPixelLorentzAngleCalibration ( const edm::ParameterSet & cfg )

explicit

Constructor.

Definition at line 146 of file SiPixelLorentzAngleCalibration.cc.

   : IntegratedCalibrationBase(cfg),
     saveToDB_(cfg.getParameter<bool>("saveToDB")),
     recordNameDBwrite_(cfg.getParameter<std::string>("recordNameDBwrite")),
     outFileName_(cfg.getParameter<std::string>("treeFile")),
     mergeFileNames_(cfg.getParameter<std::vector<std::string> >("mergeTreeFiles")),
     siPixelLorentzAngleInput_(0),
     moduleGroupSelector_(0),
     moduleGroupSelCfg_(cfg.getParameter<edm::ParameterSet>("LorentzAngleModuleGroups"))
 {
 
 }

SiPixelLorentzAngleCalibration::~SiPixelLorentzAngleCalibration ( )

virtual

Destructor.

Definition at line 160 of file SiPixelLorentzAngleCalibration.cc.

References moduleGroupSelector_, and siPixelLorentzAngleInput_.

 {
   delete moduleGroupSelector_;
   //  std::cout << "Destroy SiPixelLorentzAngleCalibration named " << this->name() << std::endl;
   delete siPixelLorentzAngleInput_;
 }

Member Function Documentation

void SiPixelLorentzAngleCalibration::beginOfJob	(	AlignableTracker *	tracker,
		AlignableMuon *	muon,
		AlignableExtras *	extras
	)

virtual

Call at beginning of job: default implementation is dummy, to be overwritten in derived class if useful.

Reimplemented from IntegratedCalibrationBase.

Definition at line 252 of file SiPixelLorentzAngleCalibration.cc.

References TkModuleGroupSelector::getNumberOfParameters(), mergeFileNames_, moduleGroupSelCfg_, moduleGroupSelector_, IntegratedCalibrationBase::name(), TkModuleGroupSelector::numIovs(), numParameters(), outFileName_, parameters_, paramUncertainties_, PixelSubdetector::PixelBarrel, PixelSubdetector::PixelEndcap, and saveToDB_.

 {
   //specify the sub-detectors for which the LA is determined
   const std::vector<int> sdets = boost::assign::list_of(PixelSubdetector::PixelBarrel)(PixelSubdetector::PixelEndcap);
   
   moduleGroupSelector_ = new TkModuleGroupSelector(aliTracker, moduleGroupSelCfg_, sdets);
 
   parameters_.resize(moduleGroupSelector_->getNumberOfParameters(), 0.);
   paramUncertainties_.resize(moduleGroupSelector_->getNumberOfParameters(), 0.);
   
   edm::LogInfo("Alignment") << "@SUB=SiPixelLorentzAngleCalibration" << "Created with name "
                             << this->name() << "',\n" << this->numParameters() << " parameters to be determined,"
                             << "\n saveToDB = " << saveToDB_
                             << "\n outFileName = " << outFileName_
                             << "\n N(merge files) = " << mergeFileNames_.size()
                             << "\n number of IOVs = " << moduleGroupSelector_->numIovs();
      
   if (mergeFileNames_.size()) {
     edm::LogInfo("Alignment") << "@SUB=SiPixelLorentzAngleCalibration"
                               << "First file to merge: " << mergeFileNames_[0];
   }
 }

bool SiPixelLorentzAngleCalibration::checkLorentzAngleInput	(	const edm::EventSetup &	setup,
		const EventInfo &	eventInfo
	)

private

If called the first time, fill 'siPixelLorentzAngleInput_', later check that LorentzAngle has not changed.

Definition at line 347 of file SiPixelLorentzAngleCalibration.cc.

References edm::ESWatcher< T >::check(), AlignmentAlgorithmBase::EventInfo::eventId_, edm::hlt::Exception, edm::EventSetup::get(), SiPixelLorentzAngle::getLorentzAngles(), edm::EventID::run(), siPixelLorentzAngleInput_, and watchLorentzAngleRcd_.

Referenced by derivatives().

 {
   edm::ESHandle<SiPixelLorentzAngle> lorentzAngleHandle;
   if (!siPixelLorentzAngleInput_) {
     setup.get<SiPixelLorentzAngleRcd>().get(lorentzAngleHandle);
     siPixelLorentzAngleInput_ = new SiPixelLorentzAngle(*lorentzAngleHandle);
   } else {
     if (watchLorentzAngleRcd_.check(setup)) { // new IOV of input
       setup.get<SiPixelLorentzAngleRcd>().get(lorentzAngleHandle);
       if (lorentzAngleHandle->getLorentzAngles() // but only bad if non-identical values
       != siPixelLorentzAngleInput_->getLorentzAngles()) { // (comparing maps)
     // Maps are containers sorted by key, but comparison problems may arise from
     // 'floating point comparison' problems (FIXME?)
     throw cms::Exception("BadInput")
       << "SiPixelLorentzAngleCalibration::checkLorentzAngleInput:\n"
       << "Content of SiPixelLorentzAngle changed at run " << eventInfo.eventId_.run()
       << ", but algorithm expects constant input!\n";
     return false; // not reached...
       }
     }
   }
   
   return true;
 }

SiPixelLorentzAngle * SiPixelLorentzAngleCalibration::createFromTree	(	const char *	fileName,
		const char *	treeName
	)		const

private

Definition at line 467 of file SiPixelLorentzAngleCalibration.cc.

References mergeVDriftHistosByStation::file, SiPixelLorentzAngle::putLorentzAngle(), query::result, diffTreeTool::tree, and relativeConstraints::value.

Referenced by getLorentzAnglesInput().

 {
   // Check for file existence on your own to work around
   // https://hypernews.cern.ch/HyperNews/CMS/get/swDevelopment/2715.html:
   TFile* file = 0;
   FILE* testFile = fopen(fileName,"r");
   if (testFile) {
     fclose(testFile);
     file = TFile::Open(fileName, "READ");
   } // else not existing, see error below
 
   TTree *tree = 0;
   if (file) file->GetObject(treeName, tree);
 
   SiPixelLorentzAngle *result = 0;
   if (tree) {
     unsigned int id = 0;
     float value = 0.;
     tree->SetBranchAddress("detId", &id);
     tree->SetBranchAddress("value", &value);
 
     result = new SiPixelLorentzAngle;
     const Long64_t nEntries = tree->GetEntries();
     for (Long64_t iEntry = 0; iEntry < nEntries; ++iEntry) {
       tree->GetEntry(iEntry);
       result->putLorentzAngle(id, value);
     }
   } else { // Warning only since could be parallel job on no events.
     edm::LogWarning("Alignment") << "@SUB=SiPixelLorentzAngleCalibration::createFromTree"
                                  << "Could not get TTree '" << treeName << "' from file '"
                                  << fileName << (file ? "'." : "' (file does not exist).");
   }
 
   delete file; // tree will vanish with file
   return result;
 }

unsigned int SiPixelLorentzAngleCalibration::derivatives	(	std::vector< ValuesIndexPair > &	outDerivInds,
		const TransientTrackingRecHit &	hit,
		const TrajectoryStateOnSurface &	tsos,
		const edm::EventSetup &	setup,
		const EventInfo &	eventInfo
	)		const

virtual

Return non-zero derivatives for x- and y-measurements with their indices by reference. Return value is their number.

Implements IntegratedCalibrationBase.

Definition at line 175 of file SiPixelLorentzAngleCalibration.cc.

References ecalTB2006H4_GenSimDigiReco_cfg::bField, Surface::bounds(), checkLorentzAngleInput(), TransientTrackingRecHit::det(), AlignmentAlgorithmBase::EventInfo::eventId_, GeomDet::geographicalId(), edm::EventSetup::get(), TkModuleGroupSelector::getParameterIndexFromDetId(), getHLTprescales::index, moduleGroupSelector_, GloballyPositioned< T >::position(), edm::EventID::run(), GeomDet::surface(), Bounds::thickness(), and GloballyPositioned< T >::toLocal().

 {
   // ugly const-cast:
   // But it is either only first initialisation or throwing an exception...
   const_cast<SiPixelLorentzAngleCalibration*>(this)->checkLorentzAngleInput(setup, eventInfo);
 
   outDerivInds.clear();
 
   if (hit.det()) { // otherwise 'constraint hit' or whatever
     
     const int index = moduleGroupSelector_->getParameterIndexFromDetId(hit.det()->geographicalId(),
                                                                        eventInfo.eventId_.run());
     if (index >= 0) { // otherwise not treated
       edm::ESHandle<MagneticField> magneticField;
       setup.get<IdealMagneticFieldRecord>().get(magneticField);
       const GlobalVector bField(magneticField->inTesla(hit.det()->surface().position()));
       const LocalVector bFieldLocal(hit.det()->surface().toLocal(bField));
       const double dZ = hit.det()->surface().bounds().thickness(); // it is a float only...
       // shift due to LA: dx = tan(LA) * dz/2 = mobility * B_y * dz/2,
       // '-' since we have derivative of the residual r = trk -hit
       const double xDerivative = bFieldLocal.y() * dZ * -0.5; // parameter is mobility!
       // FIXME: Have to treat that for FPIX yDerivative != 0., due to higher order effects! 
       if (xDerivative) { // If field is zero, this is zero: do not return it
     const Values derivs(xDerivative, 0.); // yDerivative = 0.
     outDerivInds.push_back(ValuesIndexPair(derivs, index));
       }
     }
   } else {
     edm::LogWarning("Alignment") << "@SUB=SiPixelLorentzAngleCalibration::derivatives2"
                  << "Hit without GeomDet, skip!";
   }
   
   return outDerivInds.size();
 }

void SiPixelLorentzAngleCalibration::endOfJob ( )

virtual

Called at end of a the job of the AlignmentProducer. Write out determined parameters.

Implements IntegratedCalibrationBase.

Definition at line 279 of file SiPixelLorentzAngleCalibration.cc.

References TkModuleGroupSelector::firstRunOfIOV(), SiPixelLorentzAngle::getLorentzAngles(), getLorentzAnglesInput(), getParameterError(), getParameterForDetId(), TkModuleGroupSelector::getParameterIndexFromDetId(), LaserDQM_cfg::input, edm::Service< T >::isAvailable(), moduleGroupSelector_, IntegratedCalibrationBase::name(), TkModuleGroupSelector::numIovs(), dbtoconf::out, convertSQLitetoXML_cfg::output, parameters_, paramUncertainties_, SiPixelLorentzAngle::putLorentzAngle(), recordNameDBwrite_, saveToDB_, AlCaHLTBitMon_QueryRunRegistry::string, relativeConstraints::value, cond::service::PoolDBOutputService::writeOne(), and writeTree().

 {
   // loginfo output
   std::ostringstream out;
   out << "Parameter results\n";
   for (unsigned int iPar = 0; iPar < parameters_.size(); ++iPar) {
     out << iPar << ": " << parameters_[iPar] << " +- " << paramUncertainties_[iPar] << "\n";
   }
   edm::LogInfo("Alignment") << "@SUB=SiPixelLorentzAngleCalibration::endOfJob" << out.str();
 
   std::map<unsigned int, TreeStruct> treeInfo; // map of TreeStruct for each detId
 
   // now write 'input' tree
   const SiPixelLorentzAngle *input = this->getLorentzAnglesInput(); // never NULL
   const std::string treeName(this->name() + '_');
   this->writeTree(input, treeInfo, (treeName + "input").c_str()); // empty treeInfo for input...
 
   if (input->getLorentzAngles().empty()) {
     edm::LogError("Alignment") << "@SUB=SiPixelLorentzAngleCalibration::endOfJob"
                    << "Input Lorentz angle map is empty, skip writing output!";
     return;
   }
 
   const unsigned int nonZeroParamsOrErrors =   // Any determined value?
     count_if (parameters_.begin(), parameters_.end(), std::bind2nd(std::not_equal_to<double>(),0.))
     + count_if(paramUncertainties_.begin(), paramUncertainties_.end(),
                std::bind2nd(std::not_equal_to<double>(), 0.));
 
   for (unsigned int iIOV = 0; iIOV < moduleGroupSelector_->numIovs(); ++iIOV) {
     //  for (unsigned int iIOV = 0; iIOV < 1; ++iIOV) {   // For writing out the modified values
     cond::Time_t firstRunOfIOV = moduleGroupSelector_->firstRunOfIOV(iIOV);
     SiPixelLorentzAngle *output = new SiPixelLorentzAngle;
     // Loop on map of values from input and add (possible) parameter results
     for (auto iterIdValue = input->getLorentzAngles().begin();
      iterIdValue != input->getLorentzAngles().end(); ++iterIdValue) {
       // type of (*iterIdValue) is pair<unsigned int, float>
       const unsigned int detId = iterIdValue->first; // key of map is DetId
       const double param = this->getParameterForDetId(detId, firstRunOfIOV);
       // put result in output, i.e. sum of input and determined parameter, but the nasty
       // putLorentzAngle(..) takes float by reference - not even const reference:
       float value = iterIdValue->second + param;
       output->putLorentzAngle(detId, value);
       const int paramIndex = moduleGroupSelector_->getParameterIndexFromDetId(detId,firstRunOfIOV);
       treeInfo[detId] = TreeStruct(param, this->getParameterError(paramIndex), paramIndex);
     }
 
     if (saveToDB_ || nonZeroParamsOrErrors != 0) { // Skip writing mille jobs...
       this->writeTree(output, treeInfo, (treeName + Form("result_%lld", firstRunOfIOV)).c_str());
     }
 
     if (saveToDB_) { // If requested, write out to DB 
       edm::Service<cond::service::PoolDBOutputService> dbService;
       if (dbService.isAvailable()) {
     dbService->writeOne(output, firstRunOfIOV, recordNameDBwrite_.c_str());
     // no 'delete output;': writeOne(..) took over ownership
       } else {
     delete output;
     edm::LogError("BadConfig") << "@SUB=SiPixelLorentzAngleCalibration::endOfJob"
                    << "No PoolDBOutputService available, but saveToDB true!";
       }
     } else {
       delete output;
     }
   } // end loop on IOVs
 
 }

const SiPixelLorentzAngle * SiPixelLorentzAngleCalibration::getLorentzAnglesInput ( )

private

Input LorentzAngle values:

either from EventSetup of first call to derivatives(..)
or created from files of passed by configuration (i.e. from parallel processing)

Definition at line 374 of file SiPixelLorentzAngleCalibration.cc.

References createFromTree(), SiPixelLorentzAngle::getLorentzAngles(), mergeFileNames_, IntegratedCalibrationBase::name(), siPixelLorentzAngleInput_, and AlCaHLTBitMon_QueryRunRegistry::string.

Referenced by endOfJob().

 {
   // For parallel processing in Millepede II, create SiPixelLorentzAngle
   // from info stored in files of parallel jobs and check that they are identical.
   // If this job has run on data, still check that LA is identical to the ones
   // from mergeFileNames_.
   const std::string treeName(this->name() + "_input");
   for (auto iFile = mergeFileNames_.begin(); iFile != mergeFileNames_.end(); ++iFile) {
     SiPixelLorentzAngle* la = this->createFromTree(iFile->c_str(), treeName.c_str());
     // siPixelLorentzAngleInput_ could be non-null from previous file of this loop
     // or from checkLorentzAngleInput(..) when running on data in this job as well
     if (!siPixelLorentzAngleInput_ || siPixelLorentzAngleInput_->getLorentzAngles().empty()) {
       delete siPixelLorentzAngleInput_; // NULL or empty
       siPixelLorentzAngleInput_ = la;
     } else {
       // FIXME: about comparison of maps see comments in checkLorentzAngleInput
       if (la && !la->getLorentzAngles().empty() && // single job might not have got events
           la->getLorentzAngles() != siPixelLorentzAngleInput_->getLorentzAngles()) {
         // Throw exception instead of error?
         edm::LogError("NoInput") << "@SUB=SiPixelLorentzAngleCalibration::getLorentzAnglesInput"
                                  << "Different input values from tree " << treeName
                                  << " in file " << *iFile << ".";
         
       }
       delete la;
     }
   }
 
   if (!siPixelLorentzAngleInput_) { // no files nor ran on events
     siPixelLorentzAngleInput_ = new SiPixelLorentzAngle;
     edm::LogError("NoInput") << "@SUB=SiPixelLorentzAngleCalibration::getLorentzAnglesInput"
                              << "No input, create an empty one!";
   } else if (siPixelLorentzAngleInput_->getLorentzAngles().empty()) {
     edm::LogError("NoInput") << "@SUB=SiPixelLorentzAngleCalibration::getLorentzAnglesInput"
                              << "Empty result!";
   }
 
   return siPixelLorentzAngleInput_;
 }

double SiPixelLorentzAngleCalibration::getParameter ( unsigned int index ) const

virtual

Return current value of parameter identified by index. Return 0. if index out-of-bounds.

Implements IntegratedCalibrationBase.

Definition at line 237 of file SiPixelLorentzAngleCalibration.cc.

References getHLTprescales::index, and parameters_.

Referenced by Mixins._Parameterizable::hasParameter().

 {
   return (index >= parameters_.size() ? 0. : parameters_[index]);
 }

double SiPixelLorentzAngleCalibration::getParameterError ( unsigned int index ) const

virtual

Return current value of parameter identified by index. Returns 0. if index out-of-bounds or if errors undetermined.

Implements IntegratedCalibrationBase.

Definition at line 243 of file SiPixelLorentzAngleCalibration.cc.

References getHLTprescales::index, and paramUncertainties_.

Referenced by endOfJob().

 {
   return (index >= paramUncertainties_.size() ? 0. : paramUncertainties_[index]);
 }

double SiPixelLorentzAngleCalibration::getParameterForDetId	(	unsigned int	detId,
		edm::RunNumber_t	run
	)		const

private

Determined parameter value for this detId (detId not treated => 0.) and the given run.

Definition at line 415 of file SiPixelLorentzAngleCalibration.cc.

References TkModuleGroupSelector::getParameterIndexFromDetId(), getHLTprescales::index, moduleGroupSelector_, and parameters_.

Referenced by endOfJob().

 {
   const int index = moduleGroupSelector_->getParameterIndexFromDetId(detId, run);
   return (index < 0 ? 0. : parameters_[index]);
 }

unsigned int SiPixelLorentzAngleCalibration::numParameters ( ) const

virtual

How many parameters does this calibration define?

Implements IntegratedCalibrationBase.

Definition at line 168 of file SiPixelLorentzAngleCalibration.cc.

References parameters_.

Referenced by beginOfJob().

 {
   return parameters_.size();
 }

bool SiPixelLorentzAngleCalibration::setParameter	(	unsigned int	index,
		double	value
	)

virtual

Setting the determined parameter identified by index, returns false if out-of-bounds, true otherwise.

Implements IntegratedCalibrationBase.

Definition at line 215 of file SiPixelLorentzAngleCalibration.cc.

References getHLTprescales::index, parameters_, and relativeConstraints::value.

Referenced by editorTools.UserCodeTool::__call__(), HiCoreTools.RestrictInputToAOD::__call__(), coreTools.RunOnData::__call__(), trackTools.MakeAODTrackCandidates::__call__(), metTools.AddMETCollection::__call__(), editorTools.ChangeSource::__call__(), jetTools.AddJetCollection::__call__(), HiCoreTools.RemoveMCMatching::__call__(), cmsswVersionTools.PickRelValInputFiles::__call__(), coreTools.RemoveMCMatching::__call__(), trackTools.MakePATTrackCandidates::__call__(), trigTools.SwitchOnTrigger::__call__(), HiCoreTools.RemoveAllPATObjectsBut::__call__(), HiCoreTools.RemoveSpecificPATObjects::__call__(), trigTools.SwitchOnTriggerStandAlone::__call__(), tauTools.AddTauCollection::__call__(), trackTools.MakeTrackCandidates::__call__(), trigTools.SwitchOnTriggerMatching::__call__(), HiCoreTools.RemoveCleaning::__call__(), HiCoreTools.AddCleaning::__call__(), trigTools.SwitchOnTriggerMatchingStandAlone::__call__(), jetTools.SwitchJetCollection::__call__(), jetTools.AddJetID::__call__(), trigTools.SwitchOnTriggerMatchEmbedding::__call__(), jetTools.SetTagInfos::__call__(), and metUncertaintyTools.RunMEtUncertainties::__call__().

 {
   if (index >= parameters_.size()) {
     return false;
   } else {
     parameters_[index] = value;
     return true;
   }
 }

bool SiPixelLorentzAngleCalibration::setParameterError	(	unsigned int	index,
		double	error
	)

virtual

Setting the determined parameter uncertainty identified by index, returns false if out-of-bounds, true otherwise.

Implements IntegratedCalibrationBase.

Definition at line 226 of file SiPixelLorentzAngleCalibration.cc.

References error, getHLTprescales::index, and paramUncertainties_.

 {
   if (index >= paramUncertainties_.size()) {
     return false;
   } else {
     paramUncertainties_[index] = error;
     return true;
   }
 }

void SiPixelLorentzAngleCalibration::writeTree	(	const SiPixelLorentzAngle *	lorentzAngle,
		const std::map< unsigned int, TreeStruct > &	treeInfo,
		const char *	treeName
	)		const

private

Definition at line 423 of file SiPixelLorentzAngleCalibration.cc.

References mergeVDriftHistosByStation::file, TkModuleGroupSelector::firstRunOfIOV(), SiPixelLorentzAngle::getLorentzAngles(), TkModuleGroupSelector::getParameterIndexFromDetId(), TreeStruct::LeafList(), moduleGroupSelector_, outFileName_, diffTreeTool::tree, and relativeConstraints::value.

Referenced by endOfJob().

 {
   if (!lorentzAngle) return;
 
   TFile* file = TFile::Open(outFileName_.c_str(), "UPDATE");
   if (!file) {
     edm::LogError("BadConfig") << "@SUB=SiPixelLorentzAngleCalibration::writeTree"
                    << "Could not open file '" << outFileName_ << "'.";
     return;
   }
 
   TTree *tree = new TTree(treeName, treeName);
   unsigned int id = 0;
   float value = 0.;
   TreeStruct treeStruct;
   tree->Branch("detId", &id, "detId/i");
   tree->Branch("value", &value, "value/F");
   tree->Branch("treeStruct", &treeStruct, TreeStruct::LeafList());
 
   for (auto iterIdValue = lorentzAngle->getLorentzAngles().begin();
        iterIdValue != lorentzAngle->getLorentzAngles().end(); ++iterIdValue) {
     // type of (*iterIdValue) is pair<unsigned int, float>
     id = iterIdValue->first; // key of map is DetId
     value = iterIdValue->second;
     // type of (*treeStructIter) is pair<unsigned int, TreeStruct>
     auto treeStructIter = treeInfo.find(id); // find info for this id
     if (treeStructIter != treeInfo.end()) {
       treeStruct = treeStructIter->second; // info from input map
     } else { // if none found, fill at least parameter index (using 1st IOV...)
       const cond::Time_t run1of1stIov = moduleGroupSelector_->firstRunOfIOV(0);
       const int ind = moduleGroupSelector_->getParameterIndexFromDetId(id, run1of1stIov);
       treeStruct = TreeStruct(ind);
     }
     tree->Fill();
   }
   tree->Write();
   delete file; // tree vanishes with the file... (?)
 
 }