I am a GEANT4 user I get my output in file.root format, The graphs are in TH1F format. I would like to convert these into .dat format for further refining the output.
platform : CentOS 7
root version: ROOT 5.34/36
What is this .dat format you’re referring to?
I want the numerical value of the graph points in data format (txt format).
e.g.
x f(x)
1 0.1
2 0.4
3 0.5
4 0.7
5 0.8
etc
This piece of code should work
with “g” the name of your TGraph object.
ofstream outputfile("myOutput.dat");
int N = g->GetN(); //get the number of points of the graph
double *x = g->GetX(); //get the X points
double *y = g->GetY();
for(int i=0 ; i<N ; ++i)
outputfile << i << "\t" << x[i] << "\t" << y[i] << endl; //filling the output file with the graph values
outputfile.close(); // closing the output file
or (with ROOT 5 on the command line):
root [0] gr->Print(); > myOutput.dat
with ROOT 6:
root [0] .> myOutput.dat
gr->Print()
.>
This is how I am creating my TH1F object
Energy_GAMMA = new TH1F("Energy_GAMMA","Energy_GAMMA;Energy (MeV);Counts",30,0,30);
What should be my g in this situation?
The Root file which is generated through my code is ROOTAnalysis.root.
Where should I mention that I wanted convert graphs plotted in ROOTAnalysis.root should be converted in a text file.
While running this through command line, I don’t understand where am I mentioning which root file is to converted into txt file.
Energy_GAMMA = new TH1F("Energy_GAMMA","Energy_GAMMA;Energy (MeV);Counts",30,0,30);
This is how I am creating TH1F object and the root file generated has name ROOTAnalysis.root
Ok, so with these additional informations, the code would be the following (you are not using a graph but an 1D histogram).
ofstream outputfile("myOutput.dat");
for(int i=0 ; i<30 ; ++i) //30 is your number of bins
outputfile << i << "\t" << Energy_GAMMA->GetBinCenter(i) << "\t" << Energy_GAMMA->GetBinContent(i) << endl; //filling the output file with the histogramvalues
outputfile.close(); // closing the output file
note that a histogram is much more than just points on a 2D plane.
it carries a bunch of statistical informations.
one can use root-dump to print – in ASCII art – the content of histograms (1D and 2D):
$> root-ls gauss-h1.root
=== [gauss-h1.root] ===
version: 60806
TH1D h1d h1d (cycle=1)
TH1F h1f h1f (cycle=1)
TH1F h1d-var h1d-var (cycle=1)
TH1F h1f-var h1f-var (cycle=1)
$> root-dump -name=h1d-var gauss-h1.root
>>> file[gauss-h1.root]
key[000]: h1d;1 "h1d" (TH1D)
key[001]: h1f;1 "h1f" (TH1F)
key[002]: h1d-var;1 "h1d-var" (TH1F)
BEGIN YODA_HISTO1D /h1d-var
Path=/h1d-var
Title=h1d-var
Type=Histo1D
# Mean: 2.812016e-02
# Area: 1.100600e+04
# ID ID sumw sumw2 sumwx sumwx2 numEntries
Total Total 1.100600e+04 1.211000e+04 3.094905e+02 7.128989e+04 10004
Underflow Underflow 2.000000e+00 2.000000e+00 0.000000e+00 0.000000e+00 2
Overflow Overflow 4.000000e+00 8.000000e+00 0.000000e+00 0.000000e+00 2
# xlow xhigh sumw sumw2 sumwx sumwx2 numEntries
-4.000000e+00 -3.200000e+00 6.600000e+00 7.260000e+00 0.000000e+00 0.000000e+00 6
-3.200000e+00 -2.400000e+00 7.259995e+01 7.986000e+01 0.000000e+00 0.000000e+00 66
-2.400000e+00 -1.600000e+00 5.434013e+02 5.977400e+02 0.000000e+00 0.000000e+00 494
-1.600000e+00 -8.000000e-01 1.708276e+03 1.879130e+03 0.000000e+00 0.000000e+00 1553
-8.000000e-01 0.000000e+00 3.130664e+03 3.443660e+03 0.000000e+00 0.000000e+00 2846
0.000000e+00 8.000000e-01 3.136165e+03 3.449710e+03 0.000000e+00 0.000000e+00 2851
8.000000e-01 1.600000e+00 1.753375e+03 1.928740e+03 0.000000e+00 0.000000e+00 1594
1.600000e+00 2.400000e+00 5.401014e+02 5.941100e+02 0.000000e+00 0.000000e+00 491
2.400000e+00 3.200000e+00 1.011999e+02 1.113200e+02 0.000000e+00 0.000000e+00 92
3.200000e+00 4.000000e+00 7.700000e+00 8.470000e+00 0.000000e+00 0.000000e+00 7
END YODA_HISTO1D
key[003]: h1f-var;1 "h1f-var" (TH1F)
root-dump converts TH{1,2}x histograms to YODA histograms.
That said, it seems you want to extract that data to plot it with another plotting system.
Which one is it? There is perhaps a less convoluted way to do that…
hth,
-s
Great thanks!! well this works.
But the problem it is making my simulation very slow. Since I am incorporating it within my program. So basically, I am running a geant4 program (particle tracking software) and within that, for every event it is going through the for loop and filling the respective bin.
No, Actually I need to perform some calculations over the data. And for that I need to have x and f(x) value.
If possible could you step by step tell me how to do this?
root-dump is a Go program.
once you’ve installed Go (see: Download and install - The Go Programming Language), you just have to do:
$> go get go-hep.org/x/hep/groot/cmd/root-dump
and you’re good to go.
that said, it won’t be faster than what @pamputt advised…
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I would say you should split the work. GEANT4 is designed for doing physics simulation (not analysis). So you should do you simulation and get a ROOT file as output file. Then, you write a ROOT macro to analyse your GEANT4 data. You should not do analysis work in GEANT4 itself because it will slow down the simulation (as you experienced).
I did exactly that. I got a macro written from one of my seniors for his program, but it is crashing.
I have added the query regarding the crash in the following link
https://root-forum.cern.ch/t/error-while-running-a-macro-to-view-and-convert-root-data-into-text-file/32195
Oh! Thanks for your help though. I will give it a try.