#include <rootoutput.h>

SMASH output to ROOT file

SMASH supports ROOT output as an option (see http://root.cern.ch).

The ROOT framework needs to be installed when building SMASH, otherwise ROOT support will be disabled.

This class produces file smash_run.root, which contains a ROOT TTree. TTree contains information about particles during simulation from all SMASH events. Output is happening in blocks. All particles in a block are at the same time and in the same event. However, it is possible that different blocks are at the same time and from the same event. Particle information is stored in TBranches. For each particle characteristic there is a separate branch. Currently these are t,x,y,z (coordinates), p0,px,py,pz (4-momentum), pdgid - PDG code of particle, that characterizes its sort, ev - number of event particle encountered in, tcounter - number of output block in a given event, npart - number of particles and impact_b - impact parameter.

Here is an example of ROOT macro to read the ROOT output of SMASH:

int rootfile_analysis_example() {
  // open SMASH output file to be read in
  TFile *input_file = TFile::Open("../build/data/0/smash_run.root");
  if (input_file->IsOpen()) {
    printf("Successfully opened file %s\n", input_file->GetName());
  } else {
    printf("Error at opening file %s\n", input_file->GetName());
  }
  // Get a tree from file
  TTree *tree = static_cast<TTree*>(input_file->Get("particles"));
  // Get number of entries in a tree
  Int_t nentries = tree->GetEntries();
  printf("Number of entries in a tree is %d\n", nentries);
  // This draws p_T distribution at initialization
  // tree->Draw("sqrt(px*px + py*py)","tcounter==0");
  // This draws 3D momentum space distribution at initialization
  tree->Draw("px:py:pz","tcounter==0");
  return 0;
}

For examples of extracting info from .root file see root.cern.ch To view ROOT file use TBrowser:

root -l

new TBrowser

If option write_collisions is set True, then in addition to particles TTree a collision TTree is created. Information about each collision is written as one leaf: nin, nout - number of incoming and outgoing particles, ev - event number, weight - total weight of the collision (wgt), partial_weight - partial weight of the collision (par_wgt), (t,x,y,z), (p0,px,py,pz) - arrays of dimension nin+nout that contain coordinates and momenta.

Definition at line 94 of file rootoutput.h.

Inheritance diagram for smash::RootOutput:

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Collaboration diagram for smash::RootOutput:

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Public Member Functions
	RootOutput (const bf::path &path, const std::string &name, const OutputParameters &out_par)
	Construct ROOT output. More...

	~RootOutput ()
	Destructor. More...

void	at_eventstart (const Particles &particles, const int event_number) override
	update event number and writes intermediate particles to a tree. More...

void	at_eventend (const Particles &particles, const int event_number, double impact_parameter) override
	update event number and impact parameter, and writes intermediate particles to a tree. More...

void	at_intermediate_time (const Particles &particles, const Clock &clock, const DensityParameters &dens_param) override
	Writes intermediate particles to a tree defined by treename, if it is allowed (i.e., particles_only_final_ is false). More...

void	at_interaction (const Action &action, const double density) override
	Writes collisions to a tree defined by treename. More...

Public Member Functions inherited from smash::OutputInterface
	OutputInterface (std::string name)
	Construct output interface. More...

virtual	~OutputInterface ()=default

virtual void	thermodynamics_output (const ThermodynamicQuantity tq, const DensityType dt, RectangularLattice< DensityOnLattice > &lattice)
	Output to write thermodynamics from the lattice. More...

virtual void	thermodynamics_output (const ThermodynamicQuantity tq, const DensityType dt, RectangularLattice< EnergyMomentumTensor > &lattice)
	Output to write energy-momentum tensor and related quantities from the lattice. More...

virtual void	thermodynamics_output (const GrandCanThermalizer &gct)
	Output to write energy-momentum tensor and related quantities from the thermalizer class. More...

bool	is_dilepton_output () const
	Get, whether this is the dilepton output? More...

bool	is_photon_output () const
	Get, whether this is the photon output? More...

const char *	to_string (const ThermodynamicQuantity tq)
	Convert thermodynamic quantities to strings. More...

const char *	to_string (const DensityType dens_type)
	Convert density types to strings. More...

Private Member Functions
void	particles_to_tree (const Particles &particles)
	Writes particles to a tree defined by treename. More...

void	collisions_to_tree (const ParticleList &incoming, const ParticleList &outgoing, const double weight, const double partial_weight)
	Writes collisions to a tree defined by treename. More...

void	init_trees ()
	Basic initialization routine, creating the TTree objects for particles and collisions. More...

Private Attributes
const bf::path	filename_
	Filename of output. More...

bf::path	filename_unfinished_
	Filename of output as long as simulation is still running. More...

std::unique_ptr< TFile >	root_out_file_
	Pointer to root output file. More...

TTree *	particles_tree_
	TTree for particles output. More...

TTree *	collisions_tree_
	TTree for collision output. More...

int	output_counter_ = 0
	Number of output in a given event. More...

int	current_event_ = 0
	Number of current event. More...

bool	write_collisions_
	Option to write collisions tree. More...

bool	write_particles_
	Option to write particles tree. More...

bool	particles_only_final_
	Print only final particles in the event, no intermediate output. More...

int	autosave_frequency_
	Root file cannot be read if it was not properly closed and finalized. More...


std::array< double, max_buffer_size_ >	p0
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	px
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	py
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	pz
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	t
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	x
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	y
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< double, max_buffer_size_ >	z
	Buffer for filling TTree. See class documentation for definitions. More...

std::array< int, max_buffer_size_ >	pdgcode
	Buffer for filling TTree. See class documentation for definitions. More...

int	npart
	Buffer for filling TTree. See class documentation for definitions. More...

int	tcounter
	Buffer for filling TTree. See class documentation for definitions. More...

int	ev
	Buffer for filling TTree. See class documentation for definitions. More...

int	nin
	Buffer for filling TTree. See class documentation for definitions. More...

int	nout
	Buffer for filling TTree. See class documentation for definitions. More...

double	wgt
	Buffer for filling TTree. See class documentation for definitions. More...

double	par_wgt
	Buffer for filling TTree. See class documentation for definitions. More...

double	impact_b
	Buffer for filling TTree. See class documentation for definitions. More...

Static Private Attributes
static const int	max_buffer_size_ = 10000
	Maximal buffer size. More...

Additional Inherited Members
Protected Attributes inherited from smash::OutputInterface
const bool	is_dilepton_output_
	Is this the dilepton output? More...

const bool	is_photon_output_
	Is this the photon output? More...

Constructor & Destructor Documentation

smash::RootOutput::RootOutput	(	const bf::path &	path,
		const std::string &	name,
		const OutputParameters &	out_par
	)

Construct ROOT output.

Parameters

[in]	path	Output path.
[in]	name	Name of the ouput.
[in]	out_par	A structure containing parameters of the output.

Definition at line 79 of file rootoutput.cc.

     : OutputInterface(name),
       filename_(path / (name + ".root")),
       write_collisions_(name == "Collisions" || name == "Dileptons" ||
                         name == "Photons"),
       write_particles_(name == "Particles"),
       particles_only_final_(out_par.part_only_final),
       autosave_frequency_(1000) {
   const auto &log = logger<LogArea::Output>();
   if (out_par.part_extended || out_par.coll_extended) {
     log.warn() << "Creating Root output: There is no extended Root format.";
   }
   filename_unfinished_ = filename_;
   filename_unfinished_ += ".unfinished";
   root_out_file_ =
       make_unique<TFile>(filename_unfinished_.native().c_str(), "NEW");
   init_trees();
 }

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smash::RootOutput::~RootOutput ( )

Destructor.

RootOutput destructor.

Writes root objects (here TTrees) to file and closes it.

Definition at line 149 of file rootoutput.cc.

                         {
   // kOverwrite option prevents from writing extra TKey objects into root file
   root_out_file_->Write("", TObject::kOverwrite);
   root_out_file_->Close();
   bf::rename(filename_unfinished_, filename_);
 }

Member Function Documentation

void smash::RootOutput::at_eventstart	(	const Particles &	particles,
		const int	event_number
	)

overridevirtual

update event number and writes intermediate particles to a tree.

Parameters

[in]	particles	Particles to be written to output.
[in]	event_number	event number to be used in ROOT output.

Implements smash::OutputInterface.

Definition at line 156 of file rootoutput.cc.

                                                        {
   // save event number
   current_event_ = event_number;
 
   if (write_particles_ && !particles_only_final_) {
     output_counter_ = 0;
     // This is to have only one output of positive impact parameter per event
     impact_b = -1.0;
     particles_to_tree(particles);
     output_counter_++;
   }
 }

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void smash::RootOutput::at_eventend	(	const Particles &	particles,
		const int	event_number,
		double	impact_parameter
	)

overridevirtual

update event number and impact parameter, and writes intermediate particles to a tree.

Parameters

[in]	particles	Particles to be written to output.
[in]	event_number	event number to be used in ROOT output.
[in]	impact_parameter	event number to be used in ROOT output. [fm]

Implements smash::OutputInterface.

Definition at line 178 of file rootoutput.cc.

                                                       {
   impact_b = impact_parameter;
   if (write_particles_) {
     particles_to_tree(particles);
   }
   /* Forced regular dump from operational memory to disk. Very demanding!
    * If program crashes written data will NOT be lost. */
   if (current_event_ > 0 && current_event_ % autosave_frequency_ == 0) {
     if (write_particles_) {
       particles_tree_->AutoSave("SaveSelf");
     }
     if (write_collisions_) {
       collisions_tree_->AutoSave("SaveSelf");
     }
   }
 }

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void smash::RootOutput::at_intermediate_time	(	const Particles &	particles,
		const Clock &	clock,
		const DensityParameters &	dens_param
	)

overridevirtual

Writes intermediate particles to a tree defined by treename, if it is allowed (i.e., particles_only_final_ is false).

Parameters

[in]	particles	Particles to be written to output.
[in]	clock	Unused, needed since inherited.
[in]	dens_param	Unused, needed since inherited.

Reimplemented from smash::OutputInterface.

Definition at line 170 of file rootoutput.cc.

                                                                  {
   if (write_particles_ && !particles_only_final_) {
     particles_to_tree(particles);
     output_counter_++;
   }
 }

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void smash::RootOutput::at_interaction	(	const Action &	action,
		const double	density
	)

overridevirtual

Writes collisions to a tree defined by treename.

Parameters

[in]	action	an Action object containing incoming, outgoing particles and type of interactions.
[in]	density	Unused, needed since inherited.

Reimplemented from smash::OutputInterface.

Definition at line 197 of file rootoutput.cc.

                                                 {
   if (write_collisions_) {
     collisions_to_tree(action.incoming_particles(), action.outgoing_particles(),
                        action.get_total_weight(), action.get_partial_weight());
   }
 }

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void smash::RootOutput::particles_to_tree ( const Particles & particles )

private

Writes particles to a tree defined by treename.

Parameters

[in] particles Particles to be written to output.

Definition at line 205 of file rootoutput.cc.

                                                              {
   int i = 0;
 
   tcounter = output_counter_;
   ev = current_event_;
 
   for (const auto &p : particles) {
     // Buffer full - flush to tree, else fill with particles
     if (i >= max_buffer_size_) {
       npart = max_buffer_size_;
       i = 0;
       particles_tree_->Fill();
     } else {
       t[i] = p.position().x0();
       x[i] = p.position().x1();
       y[i] = p.position().x2();
       z[i] = p.position().x3();
 
       p0[i] = p.momentum().x0();
       px[i] = p.momentum().x1();
       py[i] = p.momentum().x2();
       pz[i] = p.momentum().x3();
 
       pdgcode[i] = p.pdgcode().get_decimal();
 
       i++;
     }
   }
   // Flush rest to tree
   if (i > 0) {
     npart = i;
     particles_tree_->Fill();
   }
 }

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void smash::RootOutput::collisions_to_tree	(	const ParticleList &	incoming,
		const ParticleList &	outgoing,
		const double	weight,
		const double	partial_weight
	)

private

Writes collisions to a tree defined by treename.

Parameters

[in]	incoming	Incoming particles to be written to output.
[in]	outgoing	Outgoing particles to be written to output.
[in]	weight	Total weight of the collision.
[in]	partial_weight	Partial weight of the collision

Definition at line 240 of file rootoutput.cc.

                                                                  {
   ev = current_event_;
   nin = incoming.size();
   nout = outgoing.size();
   npart = nin + nout;
   wgt = weight;
   par_wgt = partial_weight;
 
   int i = 0;
 
   /* It is assumed that nin + nout < max_buffer_size_
    * This is true for any possible reaction for current buffer size: 10000
    * But if one wants initial/final particles written to collisions
    * then implementation should be updated. */
 
   for (const auto &p : incoming) {
     t[i] = p.position().x0();
     x[i] = p.position().x1();
     y[i] = p.position().x2();
     z[i] = p.position().x3();
 
     p0[i] = p.momentum().x0();
     px[i] = p.momentum().x1();
     py[i] = p.momentum().x2();
     pz[i] = p.momentum().x3();
 
     pdgcode[i] = p.pdgcode().get_decimal();
 
     i++;
   }
 
   for (const auto &p : outgoing) {
     t[i] = p.position().x0();
     x[i] = p.position().x1();
     y[i] = p.position().x2();
     z[i] = p.position().x3();
 
     p0[i] = p.momentum().x0();
     px[i] = p.momentum().x1();
     py[i] = p.momentum().x2();
     pz[i] = p.momentum().x3();
 
     pdgcode[i] = p.pdgcode().get_decimal();
 
     i++;
   }
 
   collisions_tree_->Fill();
 }

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void smash::RootOutput::init_trees ( )

private

Basic initialization routine, creating the TTree objects for particles and collisions.

Definition at line 99 of file rootoutput.cc.

                             {
   if (write_particles_) {
     particles_tree_ = new TTree("particles", "particles");
 
     particles_tree_->Branch("npart", &npart, "npart/I");
     particles_tree_->Branch("impact_b", &impact_b, "impact_b/D");
     particles_tree_->Branch("ev", &ev, "ev/I");
     particles_tree_->Branch("tcounter", &tcounter, "tcounter/I");
 
     particles_tree_->Branch("pdgcode", &pdgcode[0], "pdgcode[npart]/I");
 
     particles_tree_->Branch("p0", &p0[0], "p0[npart]/D");
     particles_tree_->Branch("px", &px[0], "px[npart]/D");
     particles_tree_->Branch("py", &py[0], "py[npart]/D");
     particles_tree_->Branch("pz", &pz[0], "pz[npart]/D");
 
     particles_tree_->Branch("t", &t[0], "t[npart]/D");
     particles_tree_->Branch("x", &x[0], "x[npart]/D");
     particles_tree_->Branch("y", &y[0], "y[npart]/D");
     particles_tree_->Branch("z", &z[0], "z[npart]/D");
   }
 
   if (write_collisions_) {
     collisions_tree_ = new TTree("collisions", "collisions");
 
     collisions_tree_->Branch("nin", &nin, "nin/I");
     collisions_tree_->Branch("nout", &nout, "nout/I");
     collisions_tree_->Branch("npart", &npart, "npart/I");
     collisions_tree_->Branch("ev", &ev, "ev/I");
     collisions_tree_->Branch("weight", &wgt, "weight/D");
     collisions_tree_->Branch("partial_weight", &par_wgt, "partial_weight/D");
 
     collisions_tree_->Branch("pdgcode", &pdgcode[0], "pdgcode[npart]/I");
 
     collisions_tree_->Branch("p0", &p0[0], "p0[npart]/D");
     collisions_tree_->Branch("px", &px[0], "px[npart]/D");
     collisions_tree_->Branch("py", &py[0], "py[npart]/D");
     collisions_tree_->Branch("pz", &pz[0], "pz[npart]/D");
 
     collisions_tree_->Branch("t", &t[0], "t[npart]/D");
     collisions_tree_->Branch("x", &x[0], "x[npart]/D");
     collisions_tree_->Branch("y", &y[0], "y[npart]/D");
     collisions_tree_->Branch("z", &z[0], "z[npart]/D");
   }
 }

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Member Data Documentation

const bf::path smash::RootOutput::filename_

private

Filename of output.

Definition at line 144 of file rootoutput.h.

bf::path smash::RootOutput::filename_unfinished_

private

Filename of output as long as simulation is still running.

Definition at line 146 of file rootoutput.h.

std::unique_ptr<TFile> smash::RootOutput::root_out_file_

private

Pointer to root output file.

Definition at line 148 of file rootoutput.h.

TTree* smash::RootOutput::particles_tree_

private

TTree for particles output.

TFile takes ownership of all TTrees. That's why TTree is not a unique pointer.

Definition at line 155 of file rootoutput.h.

TTree* smash::RootOutput::collisions_tree_

private

TTree for collision output.

TFile takes ownership of all TTrees. That's why TTree is not a unique pointer.

Definition at line 162 of file rootoutput.h.

int smash::RootOutput::output_counter_ = 0

private

Number of output in a given event.

Definition at line 179 of file rootoutput.h.

int smash::RootOutput::current_event_ = 0

private

Number of current event.

Definition at line 181 of file rootoutput.h.

const int smash::RootOutput::max_buffer_size_ = 10000

staticprivate

Maximal buffer size.

Definition at line 184 of file rootoutput.h.

std::array<double, max_buffer_size_> smash::RootOutput::p0

private