{

// Header
gROOT->Reset();
gROOT->SetStyle("Plain");
#include "Riostream.h";
	
// Arrays
Int_t lines = 23;
Double_t x[lines], y0[lines], y1[lines];
Double_t xErr[lines], y0Err[lines], y1Err[lines];
Double_t xError = 0.1, y0Error = 0.001, y1Error = 0.001;
	
// Daten einlesen
ifstream in;

in.open("nicht-lin_neu.txt");
	Int_t n=0;
	while (1) {
		in >> x[n] >> y0[n] >> y1[n];
		x[n]=x[n]*1000;
		xErr[n]=xError*1000;
		y0[n] = (y0[n]/2) - (y1[n]/2);
		y0Err[n] = sqrt( (y0Error**2)/4 + (y1Error**2)/4 );
		cout << x[n] << " <--> " << y0[n] << " <--> " << y1[n] << endl;
		if(!in.good()) break;
		n++;
	}
in.close();

cout << "n = " << n << endl;

// Canvas & Style
c1 = new TCanvas("c1","Canvas",1);
c1->SetGrid();
gStyle->SetOptFit();

// Graphen
gr = new TGraphErrors(n,x,y0,xErr,y0Err);
gr->SetTitle("Resonanzkurve linearer Schwingkreises");
gr->GetYaxis()->SetTitle("U / U_{treib}");
gr->GetXaxis()->SetTitle("f / Hz");
gr->GetYaxis()->CenterTitle(1);
gr->SetMarkerStyle(1);

//Funktionen
//TF1 *fitfunc = new TF1("fitfunc", "10 * [0] / (sqrt( ([0] - x**2)**2 + ([1]**2) * (x**2) ) )",1.5e5,3e5);
TF1 *fitfunc = new TF1("fitfunc", "[0]+10*[1]/(sqrt(([1]-x**2)**2+[2]**2*x**2))",1.5e5,3e5);
fitfunc->SetParameters(-5,2.344e8,1500);
//fitfunc->SetParameters(-5,9e8,0.2);
//fitfunc->SetParameters(-0.04,1.95e9,1.55e6);
//fitfunc->SetParameters(-0.5,1.165e9,5e3);
//fitfunc->SetParameters(2.344e6,3000);
//fitfunc->SetParLimits(0,-10,-1);
//fitfunc->SetParLimits(1,1e5,1e10);
//fitfunc->SetParLimits(1,9e8,9e8);
//fitfunc->SetParLimits(2,1e3,1e8);
//fitfunc->SetParLimits(2,0,0.5);

gr->Fit("fitfunc","R");
gr->Draw("AP");

Double_t chi_red = fitfunc->GetChisquare() / fitfunc->GetNDF();
cout << "Chi-Square = " << chi_red << endl;

}