Problem Macro crashes

[faca87]

Hello, I’m using an old macro that I used to fit data from file, to just plot data.
Unfortunately, deleting the lines regarding of the fit, the macro crashes and I can’ understand the reason because of

Moreover, I would add tow coordinates line as in this graph

to show to students that in a RC circuit the time constant is the time to charge the capacitor at 63%…then, given that in my data the time costant is 10s, I need two coordinates line at time=10s and at the releated voltage value (about 3,15V). Is it possible to do it?
Here the macro and the data file
data2.txt (801 Bytes)
RC.cpp (1.5 KB)

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[couet]

void RC() {
   const char *datain = "data2.txt";
   const char *dataout = "RC.pdf";
   TCanvas *c01 = new TCanvas("c01","Graph",1280,1024);
   float offx=1.3;
   float offy=1.3;
   float margr=0.08;
   float w=3;
   float margl=0.12;
   float line=2;
   gPad->SetLeftMargin(margl);
   gPad->SetRightMargin(margr);
   TGraph *graph = new TGraph(datain,"%lg %lg");
   graph->SetMarkerColor(kBlue);
   graph->SetLineColor(kBlue);
   graph->SetMarkerStyle(3);
   graph->SetMarkerSize(1.3);
   graph->SetLineWidth(line);
   TPaveText *t=new TPaveText(0.7,0.15,0.75,0.2,"brNDC");
   graph->Draw("ap");
   graph->SetTitle("RC circuit");
   graph->GetXaxis()->SetTitle("Time (s)");
   graph->GetYaxis()->SetTitle("Voltage (V)");
   graph->GetYaxis()->SetTitleOffset(offy);
   graph->GetXaxis()->SetTitleOffset(offx);
   TLegend* leg = new TLegend(0.15, 0.75, .25, .85);
   leg->SetHeader("Legend");
   leg->SetNColumns(1);
   leg->AddEntry(graph, "Data", "ap");
   leg->Draw();
   c01->Print(dataout);
}

[faca87]

Thank you @couet… it worked, but I can’t notice what you fixed…can you tell me it please?
Moreover, is there a way to do this

@faca87

Moreover, I would add tow coordinates line as in this graph

to show to students that in a RC circuit the time constant is the time to charge the capacitor at 63%…then, given that in my data the time costant is 10s, I need two coordinates line at time=10s and at the releated voltage value (about 3,15V). Is it possible to do it?

[couet]

@faca87

but I can’t notice what you fixed…can you tell me it please

can’t you do a diff ?

[faca87]

Oh yes! Now I noticed it! The stat box!

[couet]

@faca87

Moreover, is there a way to do this

You will need to draw two dotted TLine and two TLatex at the proper positions.

[faca87]

Thank you @couet, I did it!