#include <vector>
using namespace std;


#include "StandardLabels.C"

int GetIntegral(const char *fname, double &integral);


void eff_vs_z(void)
{
	vector<double> integral_Mpipi;
	vector<double> z_vals;
	for(int z=1; z<=79 ; z+=2){
		char fname[256];
		sprintf(fname, "../OUTPUT.2/z%d.root", z);
		
		double integral;
		if(GetIntegral(fname, integral) != 0)continue;
		
		integral/=100000; // normalize to number of events
		
		integral_Mpipi.push_back(integral);
		z_vals.push_back((double)z);
	}
	
	TGraphErrors *g = new TGraphErrors(z_vals.size(), &z_vals[0], &integral_Mpipi[0]);
	g->SetMarkerStyle(20);
	
	TCanvas *c1 = new TCanvas("c1");
	c1->SetTicks();
	c1->SetGridy();
	
	TH2D *axes = new TH2D("axes", "Rough efficiency vs. target position", 100, 0.0, 80.0, 100, 0.0, 1.1);
	axes->SetStats(0);
	axes->SetXTitle("Target Position (cm)");
	axes->SetYTitle("Num. #pi^{+}#pi^{-} pairs/Num. generated events");
	axes->Draw();
	
	g->Draw("P");
	
	StandardLabels(axes, "100k #pi^{+}#pi^{-} events generated"
		, "0.2 #leq m_{#pi#pi recon} #leq 0.5"
		, "vertex constraint fixed at z=65cm (i.e. not at actual vertex location)"
		, "");
	
	c1->SaveAs("eff_vs_z.png");
	c1->SaveAs("eff_vs_z.pdf");
}

int GetIntegral(const char *fname, double &integral)
{
	TFile f(fname);
	if(!f.IsOpen())return -1;

	TH1D *h = (TH1D*)gROOT->FindObject("mass_pip_pim");
	integral = h->Integral(h->FindBin(0.2), h->FindBin(0.5));

	f.Close();
}