Histogram draw (draw a simple line connecting all histogram bin points)

NewRootUser · October 7, 2020, 3:58am

I have 3 histogram and 1 graph file. I want to draw the line between the histogram bins directly as it is drawn in case of graph. How can I modify the following code.
I’m attaching the file and result file as well rootf.zip (58.0 KB) .

{
  TFile *f1 = TFile::Open("N.root");
   TCanvas *c = (TCanvas *)f1->Get("c1");
   TGraphErrors *g1 = (TGraphErrors *)c->GetListOfPrimitives()->FindObject("Graph");
   c->Close();
  g1->GetXaxis()->SetRangeUser(0,6);
 g1->GetYaxis()->SetRangeUser(1,1000);
   
   g1->SetMarkerStyle(23);
   g1->Draw("L");
   g1->GetXaxis()->SetNdivisions(509);
   gPad->SetLogy();

 
   TFile *f2 = TFile::Open("hist1.root");
   TH1D* h1 = (TH1D*)f2->Get("h16");
   h1->Draw("hist same");
   h1->SetLineStyle(10);
   h1->SetMarkerStyle(26);
   h1->SetLineColor(9);
   h1->SetLineWidth(2);

   TFile *f3 = TFile::Open("hist2.root");
   TH1D* h2 = (TH1D*)f3->Get("h16");
   h2->Draw("hist same");
   h2->SetName("b");
   h2->SetLineStyle(9);
   h2->SetMarkerStyle(29);
   h2->SetLineColor(1);
   h2->SetLineWidth(2);

   TFile *f4 = TFile::Open("hist3.root");
   TH1D* h3 = (TH1D*)f4->Get("h16");
   h3->Draw("hist same");
   h3->SetName("b");
   h3->SetLineStyle(8);
   h3->SetMarkerStyle(24);
   h3->SetLineColor(80);
   h3->SetLineWidth(2);

   auto leg = new TLegend(0.51,0.69,0.9,0.9);
   leg->SetHeader("Final");
   leg->AddEntry(g1,"graph","p");
   leg->AddEntry(h1, "hist1","l");
   leg->AddEntry(h2, "hist2","l");
   leg->AddEntry(h3,"hist3","l");
  
   leg->SetFillColor(10);
   leg->Draw();
}

Thanks. Looking forward for the answer.

ROOT Version: 16.04
Platform: Ubuntu 20.04
Compiler: Not Provided

dastudillo · October 7, 2020, 5:30am

Try including theoption “L” when drawing them.

NewRootUser · October 7, 2020, 6:26am

Thanks for the reply but this does not work. I have tried all the options and the above-shown fig is the best what I got. Draw panel helps to get a marker at the peak of each bar but the issue of connecting line remains the same.

dastudillo · October 7, 2020, 6:57am

This

void aa()
{
   auto C = new TCanvas();
 
   gStyle->SetOptTitle(kFALSE);
   gStyle->SetOptStat(0);
 
   auto h1 = new TH1F ("h1","Histogram drawn with full circles",5,-4,4);
   auto h2 = new TH1F ("h2","Histogram drawn with full squares",5,-4,4);
 
   TRandom3 rng;
   Double_t px,py;
   for (Int_t i = 0; i < 25000; i++) {
      rng.Rannor(px,py);
      h1->Fill(px,10.);
      h2->Fill(px, 8.);
   }
   h1->SetMarkerStyle(kFullCircle);
   h2->SetMarkerStyle(kFullSquare);

h1->SetLineStyle(10);
h1->SetMarkerStyle(26);
h1->SetLineColor(9);
h1->SetLineWidth(2);
h2->SetLineStyle(9);
h2->SetMarkerStyle(29);
h2->SetLineColor(1);
h2->SetLineWidth(2);

   h1->Draw("HIST L P");
   h2->Draw("HIST L P SAME");

   gPad->BuildLegend();
}

gives

NewRootUser · October 7, 2020, 8:15am

Thanks, it works but with new problems. The TGraph and TLegend got disappear.
This is what I got.


{
   TFile *f1 = TFile::Open("N.root");
   TCanvas *c = (TCanvas *)f1->Get("c1");
   TGraphErrors *g1 = (TGraphErrors *)c->GetListOfPrimitives()->FindObject("Graph");
   c->Close();
  g1->GetXaxis()->SetRangeUser(0,6);
 g1->GetYaxis()->SetRangeUser(1,1000);
   
   g1->SetMarkerStyle(23);
   //g1->Draw("AP");
   g1->SetLineColor(7);
   g1->SetLineWidth(2);
   g1->Draw("AP");
   g1->GetXaxis()->SetNdivisions(509);
   gPad->SetLogy();
 
   TFile *f2 = TFile::Open("hist1.root");
   TH1D* h1 = (TH1D*)f2->Get("h16");
   h1->Draw("hist same");
   h1->SetMarkerStyle(kFullCircle);
   h1->SetLineStyle(10);
h1->SetMarkerStyle(26);
h1->SetLineColor(9);
h1->SetLineWidth(2);
h1->Draw("HIST L P");
 
   TFile *f3 = TFile::Open("hist2.root");
   TH1D* h2 = (TH1D*)f3->Get("h16");
   h2->SetMarkerStyle(kFullSquare);
   h2->SetLineStyle(9);
h2->SetMarkerStyle(29);
h2->SetLineColor(1);
h2->SetLineWidth(2);
h2->Draw("HIST L P SAME");
   
 
      auto leg = new TLegend(0.51,0.69,0.9,0.9);
   leg->SetHeader("Final");
   leg->AddEntry(g1,"graph","");
      leg->AddEntry(h1, "hist1","l");
      leg->AddEntry(h1, "hist1","l");
}

couet · October 7, 2020, 8:19am

We are missing the ROOT files to be ables to run your macro.

couet · October 7, 2020, 8:21am

You are missing a SAME here:

   h1->Draw("HIST L P");

This command will start a new plot.
and you draw h1 twice …
and you put h1 twice in the legend … weird

couet · October 7, 2020, 8:25am

{
   TFile *f1 = TFile::Open("N.root");
   TCanvas *c = (TCanvas *)f1->Get("c1");
   TGraphErrors *g1 = (TGraphErrors *)c->GetListOfPrimitives()->FindObject("Graph");
   c->Close();
   g1->GetXaxis()->SetRangeUser(0,6);
   g1->GetYaxis()->SetRangeUser(1,1000);

   g1->SetMarkerStyle(23);
   g1->SetLineColor(7);
   g1->SetLineWidth(2);
   g1->Draw("AP");
   g1->GetXaxis()->SetNdivisions(509);
   gPad->SetLogy();

   TFile *f2 = TFile::Open("hist1.root");
   TH1D* h1 = (TH1D*)f2->Get("h16");
   h1->SetMarkerStyle(kFullCircle);
   h1->SetLineStyle(10);
   h1->SetMarkerStyle(26);
   h1->SetLineColor(9);
   h1->SetLineWidth(2);
   h1->Draw("HIST L P SAME");

   TFile *f3 = TFile::Open("hist2.root");
   TH1D* h2 = (TH1D*)f3->Get("h16");
   h2->SetMarkerStyle(kFullSquare);
   h2->SetLineStyle(9);
   h2->SetMarkerStyle(29);
   h2->SetLineColor(1);
   h2->SetLineWidth(2);
   h2->Draw("HIST L P SAME");

   auto leg = new TLegend(0.51,0.69,0.9,0.9);
   leg->SetHeader("Final");
   leg->AddEntry(g1,"graph","");
   leg->AddEntry(h1, "hist1","l");
   leg->AddEntry(h2, "hist2","l");
}

NewRootUser · October 7, 2020, 9:08am

Thanks, it worked. Just TLegend missing.
In case if you need the root file, here they are;
hist1.root (43.6 KB) hist2.root (44.0 KB) N.root (8.2 KB)

couet · October 7, 2020, 11:18am

of course you should draw the legend at the end:

   leg->Draw();

couet · October 7, 2020, 11:23am

{
   TFile *f1 = TFile::Open("N.root");
   TCanvas *c = (TCanvas *)f1->Get("c1");
   TGraphErrors *g1 = (TGraphErrors *)c->GetListOfPrimitives()->FindObject("Graph");
   c->Close();
   g1->GetXaxis()->SetRangeUser(0,6);
   g1->GetYaxis()->SetRangeUser(1,1000);

   g1->SetMarkerStyle(23);
   g1->SetLineColor(7);
   g1->SetLineWidth(2);
   g1->Draw("APL");
   g1->GetXaxis()->SetNdivisions(509);
   gPad->SetLogy();

   TFile *f2 = TFile::Open("hist1.root");
   TH1D* h1 = (TH1D*)f2->Get("h16");
   h1->SetMarkerStyle(kFullCircle);
   h1->SetLineStyle(10);
   h1->SetMarkerStyle(26);
   h1->SetLineColor(9);
   h1->SetLineWidth(2);
   h1->Draw("HIST L P SAME");

   TFile *f3 = TFile::Open("hist2.root");
   TH1D* h2 = (TH1D*)f3->Get("h16");
   h2->SetMarkerStyle(kFullSquare);
   h2->SetLineStyle(9);
   h2->SetMarkerStyle(29);
   h2->SetLineColor(1);
   h2->SetLineWidth(2);
   h2->Draw("HIST L P SAME");

   auto leg = new TLegend(0.5,0.2,0.85,0.4);
   leg->SetHeader("Final");
   leg->AddEntry(g1,"graph","PL");
   leg->AddEntry(h1, "hist1","PL");
   leg->AddEntry(h2, "hist2","PL");
   leg->Draw();
}

NewRootUser · October 7, 2020, 11:50am

Thank you to point out my silly mistake.

NewRootUser · October 10, 2020, 8:57am

Hello,
I tried with other root files and got 2 problems.
1st- When I tried with these files (1.root (14.6 KB) 2.root (44.2 KB) m1.C (850 Bytes) ) i got this result.

If I open this in TBrowser it shows the 2.root file has value at x=1 but here it’s not included.

2nd- I created c1.root file from c1.C file which has only one value(at x=5). When I draw this with hist. 2 or3.root, it create results for x=5-6 range only. How it should be modified for getting the x=1-5 range. c1.C (211 Bytes) c1.root (14.5 KB) m1.C (852 Bytes)

I tried to define the range for h1 but it does not work.

couet · October 12, 2020, 1:51pm

I do not understand what you mean… 2.root contains 21 TH1D

You file c1.root does not correspond to c1.C. When I recreate c1.root for c1.C I get the same plot.

NewRootUser · October 12, 2020, 2:39pm

1st problem - 2.root(check h16 histogram) has some value for x=1 but the line starts from x=2(which has bin value zero) in the canvas and x=1 point values are not present in this.

couet · October 12, 2020, 2:53pm

I do not see any problem with h16. Can you tell me which Drawing comment you are using ?

NewRootUser · October 12, 2020, 3:50pm

1st - If you draw 2.root (h16 histogram)(44.2 KB) and 1.root (14.6 KB) root files using m1.C (850 Bytes) then we will get this result

The highlighted point should be connected with other points of the same line(blue line) but line itself starts from point 2.

couet · October 13, 2020, 8:19am


   TFile *f1 = TFile::Open("1.root");
   TCanvas *c = (TCanvas *)f1->Get("c1");
   TGraphErrors *g1 = (TGraphErrors *)c->GetListOfPrimitives()->FindObject("Graph");
   c->Close();
   g1->GetXaxis()->SetRangeUser(0,6);
   g1->GetYaxis()->SetRangeUser(-1,200);

   g1->SetMarkerStyle(22);
   g1->SetLineColor(2);
   g1->SetLineWidth(3);
   g1->SetLineStyle(9);
   g1->Draw("");
   g1->GetXaxis()->SetNdivisions(509);

   TFile *f2 = TFile::Open("2.root");
   TH1D* h1 = (TH1D*)f2->Get("h16");
   h1->SetLineStyle(9);
   h1->SetMarkerStyle(21);
   h1->SetLineColor(9);
   h1->SetLineWidth(3);
   h1->Draw("HIST L P SAME");

   auto leg = new TLegend(0.6,0.69,0.9,0.9);
   leg->SetHeader("R");
   leg->AddEntry(g1,"1","l p");
   leg->AddEntry(h1, "2","a p l");
   leg->Draw();
}

NewRootUser · October 14, 2020, 6:26am

Thanks @couet.
2nd- In this case I want to set range of canvas from x=1-5. c1.root c1.root (14.5 KB) has single value(x=5) and 2.root(h16)2.root (44.2 KB) has x=1-5 values. How can I do it using this m1.C (852 Bytes) ? I tried to modify h1 range but didn’t work.

couet · October 14, 2020, 9:03am

you sent 1.root and 2.root but your macro access c1.root and 3.root