Tlatex location in log scale

[Keyvan_Tabaei]

hi dear experts,

i am trying to draw latex texts on a graph with the y axis log scale.

the text always appears at the top of the graph and when I try to change its location by mouse it goes at the horizontal axis and stuck there.

i tested different location values but the same thing happened.

TFile* f = new TFile(“result.root”);
TCanvas* c1 = new TCanvas(“c1”, “”);

TH2D* edepPrimaryH = (TH2D*)f->Get(“2d_PrimaryedepKernels”);
TH2D* edepFirstH = (TH2D*)f->Get(“2D_FirstedepKernels”);
TH2D* edepSecondH = (TH2D*)f->Get(“2D_SecondedepKernels”);
TH2D* edepMultipleH = (TH2D*)f->Get(“2D_MultipleedepKernels”);
TH2D* edepeBremAnnihilH = (TH2D*)f->Get(“2D_eBremAnnihiledepKernels”);
TH2D* massH = (TH2D*)f->Get(“2d_Mass”);

double ttreedose;
double ttreepol;
double ttreer;
TTree* _angle1 = new TTree(“Ntuple1”, “Edep”);
_angle1->Branch(“d”, &ttreedose, “d/D”);
_angle1->Branch(“p”, &ttreepol, “p/D”);
_angle1->Branch(“r”, &ttreer, “r/D”);

double no_photon=1e6-3170;
double to_gray=1.6091e-13;
double incident_e=1.25;
double to_centigray=1e2;
double scale=(to_grayto_centigray)/(incident_e*no_photon);

for(Int_t iphi=0;iphi<48;iphi++)
for(Int_t ir=0;ir<25;ir++)
{
double edep=edepPrimaryH->GetBinContent(iphi,ir)
+edepFirstH->GetBinContent(iphi,ir)
+edepSecondH->GetBinContent(iphi,ir)
+edepMultipleH->GetBinContent(iphi,ir)
+edepeBremAnnihilH->GetBinContent(iphi,ir);
double dose = edep/massH->GetBinContent(iphi,ir);
isoprimary->SetBinContent(iphi,0.5*(2irir+1),dose);
ttreer=0.5*(2irir+1)/10;
ttreepol=iphi;
ttreedose=dosescale;
_angle1->Fill();
}
angle1->SetLineColor(kBlack);
angle1->SetLineWidth(2);
TMultiGraph *mg = new TMultiGraph(“mg”, ";r#[]{cm};Dose#timesr^{2}{} #[]{#frac{MeV.cm^{2}{}}{Kg.Photon}}");
_angle1->Draw("drr:r",“p==0 && r<20”,“”);
mg->Add((TGraph)gPad->GetPrimitive(“Graph”)->Clone());
_angle1->Draw(“drr:r”,“p==6&&r<20”,“”);
mg->Add((TGraph*)gPad->GetPrimitive(“Graph”)->Clone());
_angle1->Draw(“drr:r”,“p==12&&r<20”,“”);
mg->Add((TGraph*)gPad->GetPrimitive(“Graph”)->Clone());
mg->Draw(“AL”);

gPad->SetLogy(1);;
TLatex latex;
latex.SetTextSize(0.018);
latex.SetTextAlign(13); //align at top
latex.DrawLatex(5,5,“0^{#circ} - 3.75^{#circ}”);
latex.DrawLatex(5,5,“22.5^{#circ} - 26.25^{#circ}”);
latex.DrawLatex(5,5,“45^{#circ} - 48.75^{#circ}”);
c1->cd();
c1->Update();

how can i draw them?
many thanks,

[Wile_E_Coyote]

Try: latex.DrawLatexNDC(0.5, 0.5, "blah blah");

[Keyvan_Tabaei]

@Wile_E_Coyote

latex.DrawLatexNDC

thank you for your reply,

@couet this is works, but if its location is changed by the mouse (when left-click mouse is released) the latext will disappear I don’t know why this is happening i don’t know it depends on the previous lines or something else.

i can set location values and don’t change it location by mouse however for better positioning and angle i prefer to set its location by mouse.

[jalopezg]

Hi @Keyvan_Tabaei,

Unfortunately, @couet is off this week and might take a while for him to reply.

Cheers,
J.

[Keyvan_Tabaei]

Hi @jalopezg
Thank you for your attention,

I used NDC and set position values.
that was not a crucial problem although it is better to know how we can use Tlatex in log scale while changing its location by mouse is possible.

[couet]

Seems to me it works fine. See that plot. I placed a text at Y = 500:

Now if I go to log scale on Y, I get this plot and the text is still at Y = 500… thats’s what we want.

[Wile_E_Coyote]

The problem description says that, when the canvas is using the “log Y” then:

@Keyvan_Tabaei

if its location is changed by the mouse (when left-click mouse is released) the latext will disappear

[couet]

I just tried. I do not see that with ROOT master. It works fine for me.