Dear Experts,
I have written a macro in which I am plotting variables from root file with a cut Kpt>0.2. I want to plot the same variable for different Kpt cut values. Kpt values should increase at the interval of 0.05 upto 2.So I have to add a for loop. Could you please tell me how to do it?
Thanks,
Deepak
Hey,
I am usually using a few simple lines of code that are not very efficient, but hey, it works.
TString cutvalue = "";
for (float cut = 0.2; cut<=2.0;cut+=0.05)
{
cutvalue +=cut;
tree->Draw("plot_variable>>HistogramKptcut"+cutvalue,"Kpt>"+cutvalue);
cutvalue="";
}
I assume you are plotting some variables stored in TTree and that “Kpt>0.2” is the selection string in TTree::Draw. As this selection parameter is a text string you need to do something like:
for (....) {
val = .....;
t->Draw ("...",Form("Kpt > %g", val), .....);
}
Hi mwojtas,
Could you please explain “plot_variable>>HistogramKptcut”+cutvalue ?
Thanks,
Deepak
@mwojtas concatenates a variable text string to the selection string to have a variable cut. It works fine but I would suggest you try the method using Form I explained in my previous post. It is more direct as you do not need a temporary text string and more flexible as you can put the varying value anywhere in the cut expression.
Hello,
As @couet said, the form() method is better. I just got used to using the concatenation. The “plot_variable>>HistogramKptcut”+cutvalue
Plots a plot_variable and saves it to a TH1 named “HistogramKptcut”+cutvalue, so for example the last histogram saved would be “HistogramKptcut2.0”. For more details on how to save drawn histograms see
https://root.cern.ch/doc/master/classTTree.html#a73450649dc6e54b5b94516c468523e45
Cheers,
Maks
Hi ,
I am pasting my macro. Please have a look.
{
TChain *ch = new TChain("tree");
ch->Add("sel_BsToPhiMuMu_mumuphi_mc_s*.root");
TTree *tr = ch;
tr->SetBranchStatus("*", kFALSE);
tr->SetBranchStatus("Bmass", kTRUE);
tr->SetBranchStatus("Kppt", kTRUE);
tr->SetBranchStatus("Kmpt", kTRUE);
tr->SetBranchStatus("Triggers", kTRUE);
TH1D *h_bm = new TH1D("h_bm" ,"B_{s} #rightarrow #mu#mu#phi; M(B_{s}) [GeV/c^{2}] ; Events/0.014GeV", 50, 5.0, 5.7);
h_bm->GetYaxis()->SetTitleOffset(1.6);
TCut trig = "Triggers ==1";
/*for(double i=0.2; i<0.5;i+=0.05)
{
TCut kp = Form("Kppt>%d",i);
// cout<<kp<<endl;
TCut km = Form("Kmpt>%d",i);
*/
TCut selbm = trig && kp && km;
//cout<<i<<endl;
/*
TString cutvalue = "";
for (float cut = 0.2; cut<=2.0;cut+=0.05)
{
cutvalue +=cut;
*/
TCanvas *cv1 = new TCanvas("cv1","",600,600);
tr->Draw("Bmass >> h_bm",selbm);
// tr->Draw("Bmass >> h_bm","Kppt>"+cutvalue);
//cout<<cutvalue<<endl;
// cutvalue="";
double Sraw, S;
double scalefactor= 864.467005076;
TAxis *axis = h_bm->GetXaxis();
int bmin = axis->FindBin(5.287);
int bmax = axis->FindBin(5.447);
double integral = h_bm->Integral(bmin,bmax);
Sraw = integral;
S= Sraw/scalefactor;
cout<<"Sraw="<<Sraw<<endl;
cout<<"S="<<S<<endl;
cv1->SaveAs("BsToPhiMuMumc2_5sigma*i.png");
}
It’s not working .
Hi,
After a brief look I can tell one main mistake, the h_bm histogram is not retrieved in a way you described. The correct way to retrieve it is:
tree.Draw("sqrt(x)>>hsqrt","y>0")
TH1F *hsqrt = (TH1F*)gDirectory->Get("hsqrt");
All of that can be found in the link I send you before. What I am not sure about is whether or not you need to have an TFile open do write to store the histograms, so you could try adding
TFile * MockFile = new TFile("mock.root ", "recreate");
in the very beginning.
Cheers,
Maks
Your macro is almost un-readable … The loops are commented… what should we keep ? the syntax is incorrect etc …
can you provide "the* real “non working macro” with a few explanations saying why it does not work.
The best would be that you provide something we could run i.e: macro + data file
Hi Couet,
I am pasting the non working macro. The loop is running but it is not changing the Kppt and Kmpt values.
{
TChain *ch = new TChain("tree");
ch->Add("sel_BsToPhiMuMu_mumuphi_mc_s0.root");
TTree *tr = ch;
tr->SetBranchStatus("*", kFALSE);
tr->SetBranchStatus("Bmass", kTRUE);
tr->SetBranchStatus("Kppt", kTRUE);
tr->SetBranchStatus("Kmpt", kTRUE);
tr->SetBranchStatus("Triggers", kTRUE);
TH1D *h_bm = new TH1D("h_bm" ,"B_{s} #rightarrow #mu#mu#phi; M(B_{s}) [GeV/c^{2}] ; Events/0.014GeV", 50, 5.0, 5.7);
h_bm->GetYaxis()->SetTitleOffset(1.6);
//TCut trig = "Triggers ==1";
for(double i=0.2; i<0.5;i+=0.05)
{
TCut trig = "Triggers ==1";
TCut kp = Form("Kppt >%d",i);
TCut km = Form("Kmpt > %d",i);
TCut selbm = trig && kp && km;
//cout<<i<<endl;
/*
TString cutvalue = "";
for (float cut = 0.2; cut<=2.0;cut+=0.05)
{
cutvalue +=cut;
*/
TCanvas *cv1 = new TCanvas "cv1","",600,600);
tr->Draw("Bmass >> h_bm",selbm);
// tr->Draw("Bmass >> h_bm","Kppt>"+cutvalue);
//cout<<cutvalue<<endl;
// cutvalue="";
double Sraw, S;
double scalefactor= 864.467005076;
TAxis *axis = h_bm->GetXaxis();
int bmin = axis->FindBin(5.287);
int bmax = axis->FindBin(5.447);
double integral = h_bm->Integral(bmin,bmax);
Sraw = integral;
S= Sraw/scalefactor;
cout<<"Sraw="<<Sraw<<endl;
cout<<"S="<<S<<endl;
cv1->SaveAs("BsToPhiMuMumc2_5sigma*i.png");
}
}
Thanks,
Deepak
i is a double not an int. do:
{
for (double i=0.2; i<0.5;i+=0.05) {
TCut trig = "Triggers ==1";
TCut kp = Form("Kppt >%g",i); // %g !... not %d !...
TCut km = Form("Kmpt > %g",i);
TCut selbm = trig && kp && km;
printf("%s\n",selbm.GetTitle());
}
}
Hi,
Here’s what I’d do: create a 2 dimensional histogram, with Kpt as second dimension! You can always create slices using ProjectX(). This is much more efficient than re-running over all tree entries for every cut value!
Axel.
Hi Couet,
Thanks,It’s working. But I have added another root file and similarly I want to calculate. But it is not working properly. I am attaching the macro .Please have a look on it. It is giving the same “S” value for all cuts where as different values for B .
{
TChain *ch = new TChain("tree");
ch->Add("sel_BsToPhiMuMu_mumuphi_mc_s0.root");
TTree *tr = ch;
tr->SetBranchStatus("*", kFALSE);
tr->SetBranchStatus("Bmass", kTRUE);
tr->SetBranchStatus("Kppt", kTRUE);
tr->SetBranchStatus("Kmpt", kTRUE);
tr->SetBranchStatus("Triggers", kTRUE);
TH1D *h_bms = new TH1D("h_bms" ,"B_{s} #rightarrow #mu#mu#phi; M(B_{s}) [GeV/c^{2}] ; Events/0.014GeV", 50, 5.0, 5.7);
h_bms->GetYaxis()->SetTitleOffset(1.6);
for (double i=0.2; i<2.0;i+=0.05) {
TCut trig = "Triggers ==1";
TCut kp = Form("Kppt >%g",i); // %g !... not %d !...
TCut km = Form("Kmpt > %g",i);
TCut selbm = trig && kp && km;
printf("%s\n",selbm.GetTitle());
TCanvas *cv1 = new TCanvas("cv1","",600,600);
tr->Draw("Bmass >> h_bms",selbm);
double Sraw, S;
double scalefactor= 864.467005076;
TAxis *axis = h_bms->GetXaxis();
int bmin = axis->FindBin(5.287);
int bmax = axis->FindBin(5.447);
double integral = h_bms->Integral(bmin,bmax);
Sraw = integral;
S= Sraw/scalefactor;
cout<<"Sraw="<<Sraw<<endl;
cout<<"S="<<S<<endl;
cv1->SaveAs("BsToPhiMuMumc2_5sigma%g,i.png");
TFile *f = new TFile("sel_BsToPhiMuMu_2016BCDEF_data_s0.root");
TTree *t1 =(TTree*)f->Get("tree");
TH1D *h_bmb = new TH1D("h_bmb" ,"B_{s} #rightarrow #mu#mu#phi Data; M(B_{s}) [GeV/c^{2}] ; Events/0.001", 700, 5.0, 5.7);
TCut bm = "Bmass < 5.223 || Bmass>5.511";
TCut selb = trig && kp && km && bm ;
printf("%s\n",selb.GetTitle());
TCanvas *cv2 = new TCanvas("cv2","",600,600);
t1->Draw("Bmass >> h_bmb",selb);
h_bmb->GetYaxis()->SetTitleOffset(1.6);
double N1,N2,B;
TAxis *axis = h_bmb->GetXaxis();
int bmin1 = axis->FindBin(5.143); //in your case xmin=-1.5
int bmax1 = axis->FindBin(5.223);
double integral1 = h_bmb->Integral(bmin1,bmax1);
N1=integral1;
cout<<"lower sideband entries"<<N1<<endl;
int bmin2 = axis->FindBin(5.511); //in your case xmin=-1.5
int bmax2 = axis->FindBin(5.591);
double integral2 = h_bmb->Integral(bmin2,bmax2);
N2=integral2;
cout<<"upper sideband entries"<<N2<<endl;
B= N1+N2;
cout<<"B="<<B<<endl;
}
}
To run your macro we are missing the file sel_BsToPhiMuMu_mumuphi_mc_s0.root
Hi Couet,
Here is the file. Please replace the second file as same as first file.
Sorry, I tried to upload the file but it is showing error in uploading for several times.
Thanks,
Deepak
If you have a CERN account, you can put it into your public folder there and post the path here.
Dear Couet,
The loop is working fine. Now I want to save only S and B values in a text file. Could you please tell me how to do it?
Thanks,
Deepak
That’s standard C++. You can easily file tutorials on the web explaining this. For instance this one.