Plot best fit with errors

Newbie
1

Hello,
How can i plot and fit the data with first degree polynomial, reading in the data from an ascii file (see attached) Run_13-19.txt (1.7 KB)
i’m tryin to use this script basic.C (2.7 KB)
instead of plotting histogram : i’m not if its wise to use TGraph *h1 = new TGraph(nlines,time,Vi_brick1) ; gStyle->SetOptFit(0001);

i’m more interested in displaying the best fit line, with its parameters and excluding the points

Thank you in advance

2 
{
  gStyle->SetStatStyle(0); // hollow
  gStyle->SetOptFit(10011);
  TTree *t = new TTree("ntuple", "data from txt file");
  t->ReadFile("Run_13-19.txt",
              "Time/I:Vi_Brick1/F:Io_Brick1:Vo_Brick1:Vi_Brick2:Io_Brick2:Vo_Brick2:Vi_Brick3:Io_Brick3:Vo_Brick3:Vi_Brick4:Io_Brick4:Vo_Brick4");
  t->SetEstimate(-1);
  // t->Print();
  t->SetMarkerStyle(kFullStar); t->SetMarkerColor(kMagenta);
  t->Draw("Vi_Brick1:Time");
  if (gPad) {
    TGraph *g = (TGraph*)gPad->GetPrimitive("Graph");
    if (g) {
      g->Fit("pol1", "Q");
#if 0 /* 0 or 1 */
      TF1 *f = (TF1*)g->GetListOfFunctions()->FindObject("pol1");
      if (f) {
        f = new TF1(*f); // make a copy
        f->Draw();
        TLatex *l = new TLatex(); l->SetTextFont(42); l->SetTextSize(0.03);
        l->DrawLatexNDC(0.35, 0.85, Form("p0 = %g #pm %g", f->GetParameter(0), f->GetParError(0)));
        l->DrawLatexNDC(0.35, 0.80, Form("p1 = %g #pm %g", f->GetParameter(1), f->GetParError(1)));
        // f->Print();
      }
#endif /* 0 or 1 */
    }
  }
}
3

I should incorporate this macro into the basic.C script?

4

If you want to display just the best fit line and exclude points on the graph, how would you go about doing that?

5 
#if 1 /* 0 or 1 */
6

doing so it doesnt display the parameters of the best fit on the plot

7

In a case where by the each parameter (Vi_brick1,Io_brick1,Vo_brick1,…) have errors that accompanies them , how can i include them in the plots?