Gaussion of a histo

ROOT
1

Hello,

I’m still learning root. Now I want to fit a gaus of the histo h1. I tried much and read in the documentation, but it dont works.

Here is my code:

[code]#include
#include
#include
#include
#include
#include
#include

vector c=0;

using namespace std;

void a()
{

std::ifstream ifs;

ifs.open (“1986.asc”, std::ifstream::in);

= ifs.get();

while (ifs.good()) {
c.push_back(ifs.get());
}

ifs.close();

TCanvas*c1 = new TCanvas(“c1”,“c1”,800,1000);

TH1F *h1 = new TH1F(“h1”,“data”,100,-5,70);
TH1F *h2 = new TH1F(“h2”,“gaus of data 1”,100,-5,70);
//TH1F *h3 = new TH1F(“h3”,“gaus of data 2”,100,-5,70);

for(int i=0;i<c.size();i++)
h1->Fill(c.at(i));
h2->Fit(“h1”);
//h3->Fit(“gaus”);

h2->SetLineColor(kGreen);
//h3->SetLineColor(kGreen);

h1->Draw();
h2->Draw(“same”);
//h3->Draw(“same”);

c1->Print(“data.pdf”);

}

[/code]

So I have a third histogram but the third one isnt important now.
Thankyou for your help

2

HI,
If you want fit histogram by gausian or any other function use TF1 class. You can see example at http://root.cern.ch/root/html/tutorials/fit/myfit.C.html