(lots more examples if you check out the 'psana_examples' package)
Psana user examples
This page holds a few example code-snippets for use in psana analysis. The analysis is written in C++ and uses root for plotting the data. (The histogramming interface allows for swapping root with any other histogramming package of your choice... in principle. If you know a good one, go ahead and try and let us know so we can try it too!!)
If you didn't already, take a look at PSDM:Psana User Manual] and Psana Reference Manual.
Note that with C++/psana (as opposed to with python/pyana), you do need two files for your source code: MyPackage/include/MyModule.h and MyPackage/src/MyModule.cpp. Also you must compile any time you change your source code.
BeamLine Data: EBeam
The bare outline... I will fill in more here.
This example shows how to create 1D and 2D histograms of data from the "BldInfo(EBeam)". The histograms gets saved automatically in a root-file, filename is the same as the xtc file name, but with extension .root, and it is stored in your current directory.
PlotBld.h
#ifndef PSANA_EXAMPLES_PLOTBLD_H
#define PSANA_EXAMPLES_PLOTBLD_H
#include "psana/Module.h"
namespace psana_examples {
class PlotBld : public Module {
public:
// Default constructor
PlotBld (const std::string& name) ;
// Destructor
virtual ~PlotBld () ;
/// Method which is called with event data
virtual void beginJob(Event& evt, Env& env);
virtual void event(Event& evt, Env& env);
protected:
private:
Source m_ebeamSrc;
PSHist::H1* m_ebeamHisto;
PSHist::H1* m_chargeHisto;
PSHist::H2* m_xPosVsAngle;
PSHist::H2* m_yPosVsAngle;
};
} // namespace psana_examples
#endif // PSANA_EXAMPLES_PLOTBLD_H
PlotBld.cpp
#include "psana_examples/PlotBld.h"
#include "MsgLogger/MsgLogger.h"
#include "psddl_psana/bld.ddl.h"
using namespace psana_examples;
PSANA_MODULE_FACTORY(PlotBld)
namespace psana_examples {
PlotBld::PlotBld (const std::string& name)
: Module(name)
{
m_ebeamSrc = configStr("eBeamSource", "BldInfo(EBeam)");
}
PlotBld::~PlotBld ()
{
}
// Method which is called once at the beginning of the job
void
PlotBld::beginJob(Event& evt, Env& env)
{
m_ebeamHisto = env.hmgr().hist1f("ebeamHisto", "ebeamL3Energy value", Axis(1000, 13000, 16000));
m_chargeHisto = env.hmgr().hist1f("chargeHisto", "ebeamCharge value", Axis(250, 0, 0.25));
m_xPosVsAngle = env.hmgr().hist2f("xPosVsAngle", "x position vs. angle; position []; angle [rad]",
Axis(100, -0.5,0.5), // x-axis: position
Axis(100,-0.5, 0.5)); // y-axis: angle
m_yPosVsAngle = env.hmgr().hist2f("yPosVsAngle", "y position vs. angle; position []; angle [rad]",
Axis(100, -0.5,0.5), // x-axis: position
Axis(100,-0.5, 0.5)); // y-axis: position
}
// Method which is called with event data
void
PlotBld::event(Event& evt, Env& env)
{
// Assume this experiment has V1 version of EBeam data
// how do you know? Try parsing xtc file with 'pyxtcreader |less'
shared_ptr<Psana::Bld::BldDataEBeamV1> ebeam = evt.get(m_ebeamSrc);
if (ebeam.get()) {
m_ebeamHisto->fill( ebeam->ebeamL3Energy() );
m_chargeHisto->fill( ebeam->ebeamCharge() );
m_xPosVsAngle->fill( ebeam->ebeamLTUPosX(),ebeam->ebeamLTUAngX() );
m_xPosVsAngle->fill( ebeam->ebeamLTUPosY(),ebeam->ebeamLTUAngY() );
// WithMsgLog(name(), info, str) {
// str << "Bld::BldDataEBeamV1:"
// << "\n damageMask=" << ebeam->damageMask()
// << "\n ebeamCharge=" << ebeam->ebeamCharge()
// << "\n ebeamL3Energy=" << ebeam->ebeamL3Energy()
// << "\n ebeamLTUPosX=" << ebeam->ebeamLTUPosX()
// << "\n ebeamLTUPosY=" << ebeam->ebeamLTUPosY()
// << "\n ebeamLTUAngX=" << ebeam->ebeamLTUAngX()
// << "\n ebeamLTUAngY=" << ebeam->ebeamLTUAngY()
// << "\n ebeamPkCurrBC2=" << ebeam->ebeamPkCurrBC2();
}
}
}
Displaying histograms.
To display the histograms graphically, open this root histogram file in a root session. Lauch root by typing 'root'. You can optionally
load the data file by adding it on the command line. The scripting syntax is like C++,
with some additional functionality:
[ofte@psana0106 ana-oct]$ root e86-r0212-s00-c00.root
*******************************************
* *
* W E L C O M E to R O O T *
* *
* Version 5.24/00 29 June 2009 *
* *
* You are welcome to visit our Web site *
* http://root.cern.ch *
* *
*******************************************
ROOT 5.24/00 (trunk@29257, Jun 30 2009, 09:23:51 on linuxx8664gcc)
CINT/ROOT C/C++ Interpreter version 5.17.00, Dec 21, 2008
Type ? for help. Commands must be C++ statements.
Enclose multiple statements between { }.
...using style 'Plain'
...using style 'Plain'
root [0]
Attaching file e86-r0212-s00-c00.root as _file0...
root [1] _file0.ls() // list the contents of the file
TFile** e86-r0212-s00-c00.root Created by the RootHManager
TFile* e86-r0212-s00-c00.root Created by the RootHManager
KEY: TH1F ebeamHisto;1 ebeamL3Energy value
KEY: TH1F chargeHisto;1 ebeamCharge value
KEY: TH2F xPosVsAngle;1 x position vs. angle
KEY: TH2F yPosVsAngle;1 y position vs. angle
root [2] ebeamHisto->Draw()
<TCanvas::MakeDefCanvas>: created default TCanvas with name c1
root [3] TCanvas c2 // to make another plot in a new window, create a new canvas.
root [4] xPosVsAngle->Draw() // this will be plotted onto the current canvas (last created)
root [5] chargeHist->Draw()
Error: Symbol chargeHist is not defined in current scope (tmpfile):1:
Error: Failed to evaluate chargeHist->Draw()
*** Interpreter error recovered ***
root [6] chargeHisto->Draw()
Overview
Content Tools