Hi,
I have 2 TGraph2D (gHadron_2D_1 and gHadron_2D_2) , one has a range of 0-1.5 in x-axis and the other has a range of 1.5-4 in x-axis. I want to connect these 2 Graphes. I tried to do this following code but the output is wrong. It doesn’t take the full range of x-axis. Can somebody help me?
Double_t x,y,z;
for(Int_t k=0; k < gHadron_2D_1->GetN(); ++k){
gHadron_2D_1->GetPoint(k,x,y,z);
gHadron_2D_2->SetPoint(k,x,y,z);
}
Hi,
can you show what is not working as expected exactly? I ran the following and I think the final TGraph2D is okay, see below:
TGraph2D *gHadron_2D_1 = new TGraph2D(5);
gHadron_2D_1->SetName("originalGraph");
gHadron_2D_1->SetPoint(0, 0.0, 10.4, 2.1); // some arbitrary numbers
gHadron_2D_1->SetPoint(1, 0.8, 8.1, 6.2);
gHadron_2D_1->SetPoint(2, 0.3, 15.6, 1.7);
gHadron_2D_1->SetPoint(3, 1.4, 9.7, 1.5);
gHadron_2D_1->SetPoint(4, 0.7, 5.3, 7.3);
TGraph2D *gHadron_2D_2 = new TGraph2D(5);
gHadron_2D_2->SetName("secondGraph");
gHadron_2D_2->SetPoint(0, 1.5, 11.3, 3.1);
gHadron_2D_2->SetPoint(1, 4.0, 6.1, 5.2);
const Int_t nPredefinedPointsOngHadron_2D_2 = gHadron_2D_2->GetN();
Double_t x,y,z;
for( Int_t k=nPredefinedPointsOngHadron_2D_2; k < gHadron_2D_1->GetN() + nPredefinedPointsOngHadron_2D_2; ++k) // k from 2 (because we already had two points predefined in gHadron_2D_2) through 2+5=7
{
gHadron_2D_1->GetPoint(k-nPredefinedPointsOngHadron_2D_2,x,y,z);
gHadron_2D_2->SetPoint(k,x,y,z);
}
gHadron_2D_2->Draw();
I tried it with:
Double_t x,y,z;
Int_t nPredefinedPointsHadron = gHadron_2D_2->GetN();
for(Int_t k= nPredefinedPointsHadron; k < gHadron_2D_1->GetN() + nPredefinedPointsHadron; ++k){
gHadron_2D_1->GetPoint(k-nPredefinedPointsHadron,x,y,z);
gHadron_2D_2->SetPoint(k,x,y,z);
cout << "Point: " << k << " m: " << x << " pt: " << y << " yield: " << z << endl;
}
The problem is that gHadron_2D_1 range of points is gonna be from 7000 to 8000.
In my case the gHadron_2D_1 has 7000 points and gHadron_2D_2 1000 points.
I did a cout in the for loop and it shows me only the values from 7000 to 8000.
Can you maybe provide a minimal reproducer along with its textual output? It’s a bit difficult to understand what is it exactly you are doing (and observing)…
I have attached you 2 root files where you get the TGraph2D. Just focus on the TGraph2D “Hadron” from these files. You can test it
TString filethermal = "/Users/thermal2D_0_10_highmass_12_10_2021.root";
TFile *file_withchiral = TFile::Open(filethermal,"READ");
TGraph2D *gHadron_2D_1 = (TGraph2D *) file_withchiral->Get("Hadron");
TString filethermal2 = "/Users/thermal2D_0_10_withchiral.root";
TFile *file_withchiral2 = TFile::Open(filethermal2,"READ");
TGraph2D *gHadron_2D_l2 = (TGraph2D *) file_withchiral2->Get("Hadron");
thermal2D_0_10_highmass_12_10_2021.root (33.3 KB)
thermal2D_0_10_withchiral.root (279.6 KB)
@zmomtaz The loop in the source code provided by @yus is adding points from the “gHadron_2D_1” to the “gHadron_2D_2” (so your “cout” shows only the “newly added” values).
{
auto c = new TCanvas();
c->Divide(3,1);
TFile *file_withchiral = TFile::Open("thermal2D_0_10_highmass_12_10_2021.root","READ");
TGraph2D *gHadron_2D_1 = (TGraph2D *) file_withchiral->Get("Hadron");
c->cd(1);
gHadron_2D_1->Draw("P0");
TFile *file_withchiral2 = TFile::Open("thermal2D_0_10_withchiral.root","READ");
TGraph2D *gHadron_2D_l2 = (TGraph2D *) file_withchiral2->Get("Hadron");
c->cd(2);
gHadron_2D_l2->Draw("P0");
auto g = new TGraph2D ();
double x,y,z;
int k;
for(k=0; k < gHadron_2D_1->GetN(); k++){
gHadron_2D_1->GetPoint(k,x,y,z);
g->AddPoint(x,y,z);
}
for(k=0; k < gHadron_2D_l2->GetN(); k++){
gHadron_2D_l2->GetPoint(k,x,y,z);
g->AddPoint(x,y,z);
}
printf("Number of points in gHadron_2D_1 = %d\n",gHadron_2D_1->GetN());
printf("Number of points in gHadron_2D_l2 = %d\n",gHadron_2D_l2->GetN());
printf("Number of points in g = %d\n",g->GetN());
c->cd(3);
g->Draw("P0");
}
Number of points in gHadron_2D_1 = 1280
Number of points in gHadron_2D_l2 = 7120
Number of points in g = 8400
Oh I am using an older Root version, so the function addpoint is not available in this version. Is it also possible to do it with Setpoint?
g->SetPoint(g->GetN(), x, y, z);
Yes of course it is possible, you need to do:
int n1 = gHadron_2D_1->GetN();
int n2 = gHadron_2D_l2->GetN();
int n = n1+n2;
auto g = new TGraph2D (n);
double x,y,z;
int k;
for(k=0; k < n1; k++){
gHadron_2D_1->GetPoint(k,x,y,z);
g->SetPoint(k,x,y,z);
or
g->SetPoint(g->GetN(), x, y, z);
}
for(k=0; k < n2; k++){
gHadron_2D_l2->GetPoint(k,x,y,z);
g->SetPoint(k+n1,x,y,z);
or
g->SetPoint(g->GetN(), x, y, z);
}
It worked, thanks to everyone!