Problem in understanding the Complex code

Newbie
1

Hi,
I am a newbie.
I was reading a code for the background elimination but unable to understand the code properly.

TSpectrum *s = new TSpectrum();
for (i = 0; i < nbins; i++) source[i]=back->GetBinContent(i + 1);
s->Background(source,nbins,10,TSpectrum::kBackDecreasingWindow,
TSpectrum::kBackOrder8,kTRUE,
TSpectrum::kBackSmoothing5,kTRUE);
for (i = 0; i < nbins; i++) d1->SetBinContent(i + 1,source[i]);

Elaborate a bit more.
Thanks in advance.

ROOT Version: 6.14
Platform: Ubuntu

2

TH1::GetBinContent
TH1::SetBinContent
TSpectrum::Background
TSpectrum manual

3

Thanks for your response @Wile_E_Coyote.
TFile *f = new TFile(file.Data());
TH1F back = (TH1F) f->Get(“back3”);
if i try to have the data points from the graph which already has all the points contained in it.
as i have
TGraph *g = new TGraph(“sample.txt”);
Int_t n = g->GetN();

then how does this code should be modified?
TH1F back = (TH1F) f->Get(“back3”);

4

Try:

TGraph *g = new TGraph("sample.txt");
TSpectrum *s = new TSpectrum();
s->Background(g->GetY(), g->GetN(),
              10, TSpectrum::kBackDecreasingWindow,
              TSpectrum::kBackOrder8, kTRUE,
              TSpectrum::kBackSmoothing5, kTRUE);
g->Draw("AL");
7

Thanks @Wile_E_Coyote

backg1
backg11297×689 6.54 KB

I don’t know whether it is fine or not?
and i don’t understand why these lines are gone below zero (see near 2000 or 4000…)
Also, don’t know where does initial histogram has gone?

8

@Wile_E_Coyote
Is the above code useful for background elimination?
As my histogram also comprises of fitted peaks.
How should i combine this code with histogram of the same file that i have drawn earlier?

9

@Wile_E_Coyote
May be i have got something. please look at it once.
Tell me how should i modify the limit of y-axis.

cleanback
cleanback1122×687 5.91 KB

I am already using:
h->SetMaximum(1000.);//along Y
h->SetMinimum(0.);