// WARNING: This script seems to only work the first 
// time it is run. Subsequent invocations cause empty
// histos. Restart ROOT before re-running!


#include "chain_fine.h"
#include "chain_course.h"
#include "StandardLabels.C"

void theta_res(void)
{
	gROOT->Reset();

	int max_events = 1000000;

	TChain *fine = chain_fine("event");
	TChain *course = chain_course("event");
	
	TCanvas *c1 = new TCanvas();
	c1->SetTicks();
	
	TH1D *thetares_fine = new TH1D("thetares_fine", "", 600, -30.0, 30.0);
	TH1D *thetares_course = new TH1D("thetares_course", "", 600, -30.0, 30.0);
	
	TCut cut1("E.thrown.E()>0.1 && E.thrown.E()<0.15");
	
	fine->Project("thetares_fine","(E.recon.p.Theta()-E.thrown.Theta())*57.3",cut1,"",max_events);
	course->Project("thetares_course","(E.recon.p.Theta()-E.thrown.Theta())*57.3",cut1,"",max_events);
	
	thetares_fine->SetLineColor(kRed);
	thetares_fine->SetLineWidth(2);
	thetares_course->SetLineColor(kBlue);
	thetares_course->SetLineWidth(2);

	thetares_fine->SetTitle("BCAL Polar angle Resolution");
	thetares_fine->SetXTitle("#theta_{rec}-#theta_{gen}(deg.)");
	thetares_fine->SetYTitle("Events/0.1 deg.");
	thetares_fine->SetStats(0);
	
	thetares_fine->Draw();
	thetares_course->Draw("same");
	
	//TH2D *axes = new TH2D("axes","BCAL Reconstruction Efficiency", 100, 0.0, 110.0, 100, 0.0, 1.05);
	//thetares_fine->SetStats(0);
	//thetares_fine->SetXTitle("#theta_{rec}-#theta_{gen} (degrees)");
	//axes->SetYTitle("Events/0.1 deg.");
	//axes->Draw();
	
	TLegend *leg = new TLegend(0.564,0.680, 0.883, 0.872);
	leg->SetFillColor(kWhite);
	leg->AddEntry(thetares_fine,"Fine Segmentation");
	leg->AddEntry(thetares_course,"Course Segmentation");
	leg->Draw();
	
	char str[256];
	sprintf(str,"%d events   No cuts on primary conversion point.", fine->GetEntries(cut1));
	
	StandardLabels1D(thetares_fine, "100MeV #leq E #leq 150MeV  10^{o}#leq#theta#leq110^{o}", "Single #gamma", str);
	
	c1->SaveAs("theta_res.png");
	c1->SaveAs("theta_res.pdf");
}