{
  // Dedomena Tash-Revma Kai peiramatika sfalnata
  double V[12]={1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};
  double I[12]={1.0, 2.0, 2.9, 4.0, 4.9, 5.9, 7.0, 8.0, 8.9, 10.0, 10.9, 11.9};

  double sfalma_V[12]={0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3};
  double sfalma_I[12]={0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2};

  TGraphErrors *gr=new TGraphErrors(12,V,I,sfalma_V,sfalma_I); // Orismos toy grafimatos

  TF1 *f1 = new TF1("f1", "pol1", 0,15); // Orismos tis synartisis prosarmogis (polyonimo 1ou vathmou)
  gStyle->SetOptFit(111); // Extypwsi toy apotelesmatos tis prosarmogis

  c1=new TCanvas("c1", "Grafima", 1000, 800);
  c1->SetFillColor(42);
  c1->SetGrid();

  gr->SetTitle ("Ohm's Law"); //Titlos grafimatos
  gr->GetXaxis()->SetTitle("V [Volts]"); //Monades ston x axona
  gr->GetYaxis()->SetTitle("I [mAmps]"); //Monacdes ston y axona

  gr->SetMarkerStyle(21) ;
  gr->SetMarkerSize(0.7);
  gr->SetMarkerColor(2) ;
  gr->SetLineColor(2) ;

  gr->Draw ("AP"); //Sxediasmos grafimatos
  gr->Fit(f1,"","",1,12); //Prosarmogi grafimatos
}