Draw histos from root file

atha.stam · August 20, 2012, 2:00pm

Hello to everyone!

I am trying to plot histos that already exist in a root file.
I can do that from terminal using

[code]thanos@thanos-laptop:~/recomm$ root run94_processed.root
root [0]
Attaching file run94_processed.root as _file0…
root [1] clu_mm2X->Scan()

Row * Instance * cl_event * cl_chambe * cl_readou * cl_chambe * cl_plane_ * cl_readou * cl_charge * cl_time *

   0 *        0 *         1 *       mm2 *         X *         0 *         0 *         0 *       681 *         2 *

   1 *        0 *         2 *       mm2 *         X *         0 *         0 *         0 *      5006 *         3 *

   2 *        0 *         3 *       mm2 *         X *         0 *         0 *         0 *       566 *         4 *

   3 *        0 *         4 *       mm2 *         X *         0 *         0 *         0 *      2729 *         2 *

   4 *        0 *         5 *       mm2 *         X *         0 *         0 *         0 *      1780 *         2 *

   5 *        0 *         6 *       mm2 *         X *         0 *         0 *         0 *       542 *         0 *

   6 *        0 *         7 *       mm2 *         X *         0 *         0 *         0 *       396 *         1 *

   7 *        0 *         8 *       mm2 *         X *         0 *         0 *         0 *      1648 *         3 *

   8 *        0 *         9 *       mm2 *         X *         0 *         0 *         0 *       322 *         3 *

   9 *        0 *        10 *       mm2 *         X *         0 *         0 *         0 *      1346 *         3 *

  10 *        0 *        11 *       mm2 *         X *         0 *         0 *         0 *       870 *         0 *

  11 *        0 *        12 *       mm2 *         X *         0 *         0 *         0 *      1572 *         0 *

  12 *        0 *        13 *       mm2 *         X *         0 *         0 *         0 *       896 *         2 *

  13 *        0 *           *           *           *           *           *           *           *           *

  14 *        0 *        15 *       mm2 *         X *         0 *         0 *         0 *      1450 *         2 *

  15 *        0 *           *           *           *           *           *           *           *           *

  16 *        0 *        17 *       mm2 *         X *         0 *         0 *         0 *       514 *         0 *

  17 *        0 *        18 *       mm2 *         X *         0 *         0 *         0 *       730 *         1 *

  18 *        0 *        19 *       mm2 *         X *         0 *         0 *         0 *      3306 *         4 *

  19 *        0 *        20 *       mm2 *         X *         0 *         0 *         0 *       470 *         1 *

  20 *        0 *           *           *           *           *           *           *           *           *

  21 *        0 *        22 *       mm2 *         X *         0 *         0 *         0 *      2411 *         2 *

  22 *        0 *        23 *       mm2 *         X *         0 *         0 *         0 *      1666 *         2 *

  23 *        0 *        24 *       mm2 *         X *         0 *         0 *         0 *       485 *         0 *

  24 *        0 *        25 *       mm2 *         X *         0 *         0 *         0 *      1057 *         0 *

Type to continue or q to quit ==> q

(Long64_t)25
root [2] clu_mm2X->Draw(“cl_charge”)
Info in TCanvas::MakeDefCanvas: created default TCanvas with name c1
root [3] .q[/code]

All I want to do is make a macro which will do it automatically.

I tried the same commands in a .c macro but it didn’t work

[code]# include “TCanvas.h”

include “TROOT.h”

include “TGraphErrors.h”

include “TStyle.h”

include “TMultiGraph.h”

include “TF1.h”

include “TLegend.h”

include “TPaveStats.h”

include “TArrow.h”

include “TLatex.h”

include “TPaveText.h”

include “TText.h”

include “TPavesText.h”

void test_recomm(){

// open file
TFile *fin = TFile::Open(“run94.root”);
fin->cd();

clu_mm2X->Draw("cl_charge");

}[/code]

Is it possible to be done?

Thank you in advance!

Pepe_Le_Pew · August 20, 2012, 2:14pm

http://root.cern.ch/drupal/content/reading-and-writing-objects
http://root.cern.ch/drupal/content/retrieving-objects-disk
http://root.cern.ch/root/html/TDirectoryFile.html#TDirectoryFile:Get
http://root.cern.ch/download/doc/ROOTUsersGuideHTML/ch12s20.html

atha.stam · August 21, 2012, 1:19pm

I’ve tried the following but it’s not working…

[code]#include
#include
#include

include “TROOT.h”

include “TGraphErrors.h”

include “TStyle.h”

include “TMultiGraph.h”

include “TF1.h”

include “TLegend.h”

include “TPaveStats.h”

include “TArrow.h”

include “TLatex.h”

include “TPaveText.h”

include “TText.h”

include “TPavesText.h”

#include “TString.h”
#include “TSystem.h”
#include “TInterpreter.h”
#include “TFile.h”
#include “TH1.h”
#include “TNtuple.h”
#include “TCanvas.h”

void test_recomm(){

// open file

//TFile * f1 = new TFile ( "run94_processed.root" ) ;
//TH1F *k1 = ( TH1F * ) f1-> Get ("clu_mm4X")->Get("cl_charge");
TFile f ("run94_processed.root");
TTree *MyTree = clu_mm4X;
//TCanvas *myCanvas = new TCanvas();
//MyTree->Draw("cl_charge");

gROOT->SetStyle(“Plain”);
gStyle->SetOptStat(1111);
gStyle->SetOptFit(1111);

TCanvas *c = new TCanvas(“c”, “cluster charge”);
c->SetFillColor(kRed);
c->SetFrameFillColor(10);

//MyTree->SetTitle(“Cluster Charge”);
gStyle->SetHistFillColor(kBlue);
MyTree->UseCurrentStyle();

//TAxis* xax = MyTree->GetXaxis();
//MyTree->SetTitle("cluster charge");
//xax->SetTitleColor(kBlue);
//----MyTree->Draw("cl_charge");---This command is really working
//MyTree->Draw("cl_charge>>h1(100,150,250)")
   
//TH1F *h1 = new TH1F;
MyTree->Draw("cl_charge>>h1(93,0,140000)");
//h1->Draw();

}
[/code]

I only get a red canvas but no histogram at all…

If I type during a root session

is working fine.

Why can’t I run through a macro?

bellenot · August 21, 2012, 1:27pm

Hi,

Try:TFile *f = TFile::Open("run94_processed.root"); TTree *MyTree = (TTree *)f->Get("clu_mm4X");
Cheers, Bertrand.

Pepe_Le_Pew · August 21, 2012, 1:30pm

TFile *f = TFile::Open("run94_processed.root"); TTree *MyTree; f->GetObject("clu_mm4X", MyTree); if (!MyTree) { std::cout << "Warning: clu_mm4X TTree NOT found!" << std::endl; return; }

atha.stam · August 21, 2012, 1:34pm

It is working!!!
As you see, I declare the histo like that

MyTree->Draw("cl_charge>>h1(93,0,140000)");

Is there a way to declare it, without having to specify bin size, xmin and xmax?
I want these variables to be automatically created.

Pepe_Le_Pew · August 21, 2012, 1:37pm

See “Saving the result of Draw to an histogram” in http://root.cern.ch/root/html/TTree.html#TTree:Draw@2 and “Filling a Histogram” in http://root.cern.ch/download/doc/ROOTUsersGuideHTML/ch12s20.html

atha.stam · August 21, 2012, 1:53pm

Thank’s for your answer!

I replaced

with

but the bin size is different from the one of the root file…

atha.stam · August 21, 2012, 4:55pm

I have tried to find a solution to that, but I couldn’t.
However, I did some improvements.
I changed the axis range, I divided the canvas, I added a pad as a title and I changed pad’s color.
My code is now like that:

[code]#include
#include
#include

include “TROOT.h”

include “TGraphErrors.h”

include “TStyle.h”

include “TMultiGraph.h”

include “TF1.h”

include “TLegend.h”

include “TPaveStats.h”

include “TArrow.h”

include “TLatex.h”

include “TPaveText.h”

include “TText.h”

include “TPavesText.h”

#include “TString.h”
#include “TSystem.h”
#include “TInterpreter.h”
#include “TFile.h”
#include “TH1.h”
#include “TNtuple.h”
#include “TCanvas.h”

void test_recomm(){

// open file

//TFile * f1 = new TFile ( "run94_processed.root" ) ;
//TH1F *k1 = ( TH1F * ) f1-> Get ("clu_mm4X")->Get("cl_charge");

TFile *f = TFile::Open("run94_processed.root");
TTree *MyTree = (TTree *)f->Get("clu_mm4X");

//TFile f ("run94_processed.root");
//TTree *MyTree = clu_mm4X;
//TCanvas *myCanvas = new TCanvas();
//MyTree->Draw("cl_charge");

gROOT->SetStyle(“Plain”);
gStyle->SetOptStat(1111);
gStyle->SetOptFit(1111);

TCanvas *c = new TCanvas(“c”, “cluster charge”);
c->SetFillColor(5 );
//c->SetFrameFillColor(5);
c->Divide(2,3);
c->cd(1);
TPaveText *pt = new TPaveText(0.2101,0.2910,0.7944,0.8278,“br”);
pt->SetFillColor(19);
TText *text=pt->AddText(“Cluster charge”);
text=pt->AddText(“charge Cluster”);
pt->Draw();
c->Modified();
c->cd();
c_4->cd();
c_4->SetFillColor(kRed);
//gStyle->SetPadColor(10);
c_4->SetFrameFillColor(10);
c_4->SetBorderMode(1);
c_4->SetBorderSize(2);

//MyTree->SetTitle(“Cluster Charge”);
gStyle->SetHistFillColor(kBlue);
MyTree->UseCurrentStyle();

//TAxis* xax = MyTree->GetXaxis();
//MyTree->SetTitle("cluster charge");
//xax->SetTitleColor(kBlue);
//----MyTree->Draw("cl_charge");---This command is really working
//MyTree->Draw("cl_charge>>h1(100,150,250)")
//MyTree->Fit("landau","W",NULL,1,20);

//TH1F *h1 = new TH1F;
MyTree->Draw("cl_charge>>h1","cl_charge>0");

//MyTree->Draw("cl_cluster>>h1(100,150,250)")

h1->SetTitle("cluster charge");
h1->Draw();
h1->Fit("landau","W",NULL,1,20000);

c->Modified(); c->Update();

c_3->cd();
c_3->SetFillColor(kRed);
//gStyle->SetPadColor(10);
c_3->SetFrameFillColor(10);
c_3->SetBorderMode(1);
c_3->SetBorderSize(2);

//MyTree->SetTitle(“Cluster Charge”);
gStyle->SetHistFillColor(kBlue);
MyTree->UseCurrentStyle();

//TAxis* xax = MyTree->GetXaxis();
//MyTree->SetTitle("cluster charge");
//xax->SetTitleColor(kBlue);
//----MyTree->Draw("cl_charge");---This command is really working
//MyTree->Draw("cl_charge>>h1(100,150,250)")
//MyTree->Fit("landau","W",NULL,1,20);

//TH1F *h1 = new TH1F;
MyTree->Draw("cl_charge>>h1","cl_charge>0");

//MyTree->Draw("cl_cluster>>h1(100,150,250)")

h1->SetTitle("cluster charge");
h1->SetAxisRange(0,20000,"X");
h1->Draw();
h1->Fit("landau","W",NULL,1,20000);

c->Modified(); c->Update();

}
[/code]

But I still cannot figure out how to have the root file’s bin size…
Any ideas?

atha.stam · August 21, 2012, 5:05pm

Please find attached the two histos that are created with both ways.
You can see that counts for first bin for “with_option_x>0” are greater than the ones for “straight from root file”.
So I assume that the bin size is different in two cases…
with_option_x>0.pdf (13.9 KB)
straight from root file.pdf (14.1 KB)

Pepe_Le_Pew · August 21, 2012, 5:11pm

A “root file” has NO embedded “bin size”.
The difference in histogram’s “entries number” can simply be the number of entries in your tree with “cl_charge<=0 || cl_charge>140000”.

atha.stam · August 21, 2012, 5:20pm

I know that a root file has no bin size.
I just meant, the histo that comes directly from the root file, if, while in root session, I give

[code]thanos@thanos-laptop:~/recomm$ root run94_processed.root
root [0]
Attaching file run94_processed.root as _file0…
root [1] .ls
TFile** run94_processed.root
TFile* run94_processed.root
KEY: TTree raw;1 rawapvdata
KEY: TTree pedestals;2 apvpedestals
KEY: TEnv DetConfig;1 Handle ROOT configuration resources
KEY: TDirectoryFile mm2;1 mm2
KEY: TDirectoryFile mm3;1 mm3
KEY: TDirectoryFile mm4;1 mm4
KEY: TGeoManager world;1 the simplest geometry
KEY: TVector3 posmm2;1 A 3D physics vector
KEY: TTree hits_mm2;1 hits_this_plane
KEY: TTree drift_mm2;1 hits_this_plane
KEY: TTree clu_mm2X;1 clusters_this_readout
KEY: TTree clu_mm2Y;1 clusters_this_readout
KEY: TVector3 posmm3;1 A 3D physics vector
KEY: TTree hits_mm3;1 hits_this_plane
KEY: TTree drift_mm3;1 hits_this_plane
KEY: TTree clu_mm3X;1 clusters_this_readout
KEY: TTree clu_mm3Y;1 clusters_this_readout
KEY: TVector3 posmm4;1 A 3D physics vector
KEY: TTree hits_mm4;1 hits_this_plane
KEY: TTree drift_mm4;1 hits_this_plane
KEY: TTree clu_mm4X;1 clusters_this_readout
KEY: TTree clu_mm4Y;1 clusters_this_readout
KEY: TPaveText ;1 PaveText. A Pave with several lines of text.
root [2] clu_mm2X->Scan()

Row * Instance * cl_event * cl_chambe * cl_readou * cl_chambe * cl_plane_ * cl_readou * cl_charge * cl_time *

   0 *        0 *         1 *       mm2 *         X *         0 *         0 *         0 *       681 *         2 *

   1 *        0 *         2 *       mm2 *         X *         0 *         0 *         0 *      5006 *         3 *

   2 *        0 *         3 *       mm2 *         X *         0 *         0 *         0 *       566 *         4 *

   3 *        0 *         4 *       mm2 *         X *         0 *         0 *         0 *      2729 *         2 *

   4 *        0 *         5 *       mm2 *         X *         0 *         0 *         0 *      1780 *         2 *

   5 *        0 *         6 *       mm2 *         X *         0 *         0 *         0 *       542 *         0 *

   6 *        0 *         7 *       mm2 *         X *         0 *         0 *         0 *       396 *         1 *

   7 *        0 *         8 *       mm2 *         X *         0 *         0 *         0 *      1648 *         3 *

   8 *        0 *         9 *       mm2 *         X *         0 *         0 *         0 *       322 *         3 *

   9 *        0 *        10 *       mm2 *         X *         0 *         0 *         0 *      1346 *         3 *

  10 *        0 *        11 *       mm2 *         X *         0 *         0 *         0 *       870 *         0 *

  11 *        0 *        12 *       mm2 *         X *         0 *         0 *         0 *      1572 *         0 *

  12 *        0 *        13 *       mm2 *         X *         0 *         0 *         0 *       896 *         2 *

  13 *        0 *           *           *           *           *           *           *           *           *

  14 *        0 *        15 *       mm2 *         X *         0 *         0 *         0 *      1450 *         2 *

  15 *        0 *           *           *           *           *           *           *           *           *

  16 *        0 *        17 *       mm2 *         X *         0 *         0 *         0 *       514 *         0 *

  17 *        0 *        18 *       mm2 *         X *         0 *         0 *         0 *       730 *         1 *

  18 *        0 *        19 *       mm2 *         X *         0 *         0 *         0 *      3306 *         4 *

  19 *        0 *        20 *       mm2 *         X *         0 *         0 *         0 *       470 *         1 *

  20 *        0 *           *           *           *           *           *           *           *           *

  21 *        0 *        22 *       mm2 *         X *         0 *         0 *         0 *      2411 *         2 *

  22 *        0 *        23 *       mm2 *         X *         0 *         0 *         0 *      1666 *         2 *

  23 *        0 *        24 *       mm2 *         X *         0 *         0 *         0 *       485 *         0 *

  24 *        0 *        25 *       mm2 *         X *         0 *         0 *         0 *      1057 *         0 *

Type to continue or q to quit ==> q

(Long64_t)25
root [3] clu_mm2X->Draw(“cl_carge”)
Error in TTreeFormula::Compile: Bad numerical expression : "cl_carge"
root [4] clu_mm2X->Draw(“cl_charge”)
Info in TCanvas::MakeDefCanvas: created default TCanvas with name c1
[/code]

I also tried

but I get the same as

clu_mm2X->Draw("cl_charge").

atha.stam · August 21, 2012, 5:25pm

Please find attached the two plots, zoomed at the first bin.
You can clearly see that the bin size is different.
Could that be a bug?
with_option_x>0.pdf (13.3 KB)
straight from root file.pdf (13.5 KB)

Pepe_Le_Pew · August 21, 2012, 5:34pm

Again, what concerns the histogram binning, i.e. in case you use Draw(“someVar”) or Draw(“someVar>>someHisto”), see “Saving the result of Draw to an histogram” in http://root.cern.ch/root/html/TTree.html#TTree:Draw@2 and “Filling a Histogram” in http://root.cern.ch/download/doc/ROOTUsersGuideHTML/ch12s20.html
You might also be interested in “Retrieving the result of Draw” in http://root.cern.ch/root/html/TTree.html#TTree:Draw@2 and “Accessing the Histogram in Batch Mode” in http://root.cern.ch/download/doc/ROOTUsersGuideHTML/ch12s20.html

atha.stam · August 21, 2012, 6:35pm

Thank you very much for your time and support!!!
What I was doing was absolutely right.
The only thing that was wrong was the fact that I was using a different tree in my macro-I was using mm4X instead of mm2X. Silly me!
But now I am having another issue…
I want to load multiple root files, that all contain same trees.
I want to print in a divided canvas histograms of the same variable for different root files.
I tried

[code]#include
#include
#include

include “TROOT.h”

include “TGraphErrors.h”

include “TStyle.h”

include “TMultiGraph.h”

include “TF1.h”

include “TLegend.h”

include “TPaveStats.h”

include “TArrow.h”

include “TLatex.h”

include “TPaveText.h”

include “TText.h”

include “TPavesText.h”

#include “TString.h”
#include “TSystem.h”
#include “TInterpreter.h”
#include “TFile.h”
#include “TH1.h”
#include “TNtuple.h”
#include “TCanvas.h”

void test_recomm(){

// open file

//TFile * f1 = new TFile ( "run94_processed.root" ) ;
//TH1F *k1 = ( TH1F * ) f1-> Get ("clu_mm4X")->Get("cl_charge");

TFile *f = TFile::Open("run94_processed.root");
TTree *MyTree = (TTree *)f->Get("clu_mm2X");


TFile *f1 = TFile::Open("run92_processed.root");
TTree *MyTree1 = (TTree *)f->Get("clu_mm2X");
//TFile f ("run94_processed.root");
//TTree *MyTree = clu_mm4X;
//TCanvas *myCanvas = new TCanvas();
//MyTree->Draw("cl_charge");

gROOT->SetStyle(“Plain”);
gStyle->SetOptStat(1111);
gStyle->SetOptFit(1111);

TCanvas *c = new TCanvas(“c”, “cluster charge”);
c->SetFillColor(5 );
//c->SetFrameFillColor(5);
c->Divide(2,3);
c->cd(1);
TPaveText *pt = new TPaveText(0.2101,0.2910,0.7944,0.8278,“br”);
pt->SetFillColor(19);
TText *text=pt->AddText(“Cluster charge”);
text=pt->AddText(“charge Cluster”);
pt->Draw();
c->Modified();
c->cd();
c_4->cd();
c_4->SetFillColor(kRed);
//gStyle->SetPadColor(10);
c_4->SetFrameFillColor(10);
c_4->SetBorderMode(1);
c_4->SetBorderSize(2);

//MyTree->SetTitle(“Cluster Charge”);
gStyle->SetHistFillColor(kBlue);
MyTree->UseCurrentStyle();

//TAxis* xax = MyTree->GetXaxis();
//MyTree->SetTitle("cluster charge");
//xax->SetTitleColor(kBlue);
//----MyTree->Draw("cl_charge");---This command is really working
//MyTree->Draw("cl_charge>>h1(100,150,250)")
//MyTree->Fit("landau","W",NULL,1,20);

//TH1F *h1 = new TH1F;
MyTree->Draw("cl_charge>>+h1","cl_charge>0");

//MyTree->Draw("cl_cluster>>h1(100,150,250)")

h1->SetTitle("cluster charge");
h1->Draw();
h1->Fit("landau","W",NULL,1,20000);

c->Modified(); c->Update();

c_3->cd();
c_3->SetFillColor(kRed);
//gStyle->SetPadColor(10);
c_3->SetFrameFillColor(10);
c_3->SetBorderMode(1);
c_3->SetBorderSize(2);

//MyTree->SetTitle(“Cluster Charge”);
gStyle->SetHistFillColor(kBlue);
MyTree1->UseCurrentStyle();

//TAxis* xax = MyTree->GetXaxis();
//MyTree->SetTitle("cluster charge");
//xax->SetTitleColor(kBlue);
//----MyTree->Draw("cl_charge");---This command is really working
//MyTree->Draw("cl_charge>>h1(100,150,250)")
//MyTree->Fit("landau","W",NULL,1,20);

//TH1F *h1 = new TH1F;
MyTree1->Draw("cl_charge>>h2");

//MyTree->Draw("cl_cluster>>h1(100,150,250)")

h2->SetTitle("apv channel");
//h2->SetAxisRange(0,7000,"X");
h2->Draw();
//h2->Fit("landau","W",NULL,1,20000);

c->Modified(); c->Update();

}
[/code]

but it’s not working.

Is it possible to be done?

Thank you in advance!

P.S.: If I have to add a new topic for that, please let me know

Pepe_Le_Pew · August 21, 2012, 6:41pm

TTree *MyTree1 = (TTree *)f1->Get(“clu_mm2X”);
BTW. You’d better learn to use “GetObject” instead of “Get”.

atha.stam · August 21, 2012, 6:52pm

I hate when this is happening!!!
Thank very much my forever root-problem-solver!!!

GetObject?
Why is that better?
Apart from my question, I trust you so I’m going to read sth about GetObject!

Pepe_Le_Pew · August 21, 2012, 6:54pm

See the “NOTE:” in http://root.cern.ch/root/html/TDirectoryFile.html#TDirectoryFile:Get