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Save histogram in txt file

ROOT
#1

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ROOT Version: 6.18.00
Platform: Ubuntu 18.04.5 LTS
Compiler: Not Provided

Good evening!

I’m run a code and save histogram generate in root file and txt, but I’m doing some wrong, because what appears in the txt is:

   TH1F *values__1 = new TH1F("values__1","Kinect Energy spectrum - Fotoes Totais",3500,0,0.0455);
   values__1->SetBinContent(317,1);
   values__1->SetBinContent(319,1);
   values__1->SetBinContent(320,1);
   values__1->SetBinContent(321,2);
   values__1->SetBinContent(323,2);
   values__1->SetBinContent(324,1);
   values__1->SetBinContent(325,2);
   values__1->SetBinContent(328,2);
   values__1->SetBinContent(329,3);
   values__1->SetBinContent(332,1);
   values__1->SetBinContent(333,2);
   values__1->SetBinContent(334,2);
   values__1->SetBinContent(335,1);
   values__1->SetBinContent(336,1);
   values__1->SetBinContent(337,3);
   values__1->SetBinContent(339,1);
   values__1->SetBinContent(340,8);
   values__1->SetBinContent(341,5);
   values__1->SetBinContent(342,3);
   values__1->SetBinContent(343,1);

But I expected that was values and what appears it is the canvas values, isn’t? what I am doing wrong?

I use ana->SaveAs(“example.txt”);

Best regards

#2

Hi,

There is no plain text storage for histogram.
But you can try json format - doing SaveAs(“example.json”);
Probably it will fit your needs.

Regards,
Sergey

#3

Thanks @linev! I see that in root5 there was some eample of macro to convert root in txt file. I think applied this but when I do some errors appears? Have you or anyone show me an example in root 6.18.00?

Best Regards!

#4

If you have ROOT5 macro, it should also work with ROOT6.
You probably can just loop over histogram bins and create text file yourself.

#5

@linev I use this code:

void dumpHistoToTxt()
{
TFile *f=new TFile("SPEC_TotalFotoes1.root"); // opens the root file
TH1F * tr=(TH1F *)f->Get("SPEC_TotalFotoes1");

float ener,value;

ofstream myfile;
myfile.open ("testeFotoes1.txt");
myfile << "ener value\n";

for (int idx=0; idx<tr->GetNbinsX();++idx) {
   ener = tr->GetBinCenter(idx);
   value = tr->GetBinContent(idx);
   cout << ener << " " << value << endl; //print to the screen
   myfile << ener << " " << value << "\n"; //write to file
}

myfile.close();
}

I use the histogram in root file.

Can you help in this? I place here the text file generated, but is wrong.

SPEC_TotalFotoes1.root (6.4 KB) SPEC_TotalFotoes1.txt (63.4 KB)

#6

I find out in other question here, this line of command that provide something:

.> values.txt
values->Print("all");
.>

This give me:

 fSumw[0]=0, x=-6.5e-06
 fSumw[1]=0, x=6.5e-06
 fSumw[2]=0, x=1.95e-05
 fSumw[3]=0, x=3.25e-05
 fSumw[4]=0, x=4.55e-05
 fSumw[5]=0, x=5.85e-05
 fSumw[6]=0, x=7.15e-05
 fSumw[7]=0, x=8.45e-05
 fSumw[8]=0, x=9.75e-05
 fSumw[9]=0, x=0.0001105
 fSumw[10]=0, x=0.0001235
 fSumw[11]=0, x=0.0001365

But what I need is:
x y
energy count
0.001105 1000

Could I do it?

Thanks

best regards

#7

TH1F *tr; f->GetObject("values", tr);

#8

Thanks for the repllied @Wile_E_Coyote!

I substitued the

TH1F * tr=(TH1F *)f->Get("SPEC_TotalFotoes1");

to

TH1F *tr; f->GetObject("values", tr);

This give me:

0.0001105 0.0001105
0.0001235 0.0001235
0.0001365 0.0001365
0.0001495 0.0001495
0.0001625 0.0001625
0.0001755 0.0001755

But my Y axis is the count generated from the attached file, it is possible do it? In file I save the histogram a root file, but I need the data in a txt file.
specTi.C (13.7 KB) specTi.h (17.3 KB)

Best regards!

#9

Sorry, I cannot identify place where you make printout.
But seems to be you just print GetBinCenter value twice

#10

Thanks, @linev for the repllied. I notice that in the code that I use was place the BinCenter twice. When I fixed this, was correct now.

Thanks all for the help.

One doubt more: It’s possible to add a third column that will represent the normalize integral to 1?

Best Regards

#11

You can use GetIntegral method to normalize your values:

double integral = tr->ComputeIntegral();
...
   ener = tr->GetBinCenter(idx);
   value = tr->GetBinContent(idx);
   value_normalized = value / integral;