// 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_rms_vs_E(void)
{
	gROOT->Reset();

	int max_events = 1000000;

	TChain *fine = chain_fine("event");
	TChain *course = chain_course("event");
	
	TCanvas *c1 = new TCanvas();
	c1->SetTicks();
	
	TH2D *thetares_fine = new TH2D("thetares_fine", "", 50, 0.0, 2.0, 80, -20.0, 20.0);
	TH2D *thetares_course = new TH2D("thetares_course", "", 50, 0.0, 2.0, 80, -20.0, 20.0);
	
	TCut cut1("");
	
	fine->Project("thetares_fine","(E.recon.p.Theta()-E.thrown.Theta())*57.3:E.thrown.E()",cut1,"",max_events);
	course->Project("thetares_course","(E.recon.p.Theta()-E.thrown.Theta())*57.3:E.thrown.E()",cut1,"",max_events);
	
	TH1D *thetares_fine_2 = MakeRMSHisto(thetares_fine);
	TH1D *thetares_course_2 = MakeRMSHisto(thetares_course);
	
	thetares_fine_2->SetLineColor(kRed);
	thetares_fine_2->SetLineWidth(2);
	thetares_course_2->SetLineColor(kBlue);
	thetares_course_2->SetLineWidth(2);

	TH2D *axes = new TH2D("axes","BCAL Reconstruction Efficiency", 100, 0.0, 2.0, 100, 0.0, 6.0);
	axes->SetStats(0);
	axes->SetYTitle("RMS(#theta_{rec}-#theta_{gen}) (deg.)");
	axes->SetXTitle("E_{#gamma} (GeV)");
	axes->Draw();

	thetares_fine_2->Draw("same");
	thetares_course_2->Draw("same");
	
	TLegend *leg = new TLegend(0.564,0.680, 0.883, 0.872);
	leg->SetFillColor(kWhite);
	leg->AddEntry(thetares_fine_2,"Fine Segmentation");
	leg->AddEntry(thetares_course_2,"Course Segmentation");
	leg->Draw();
	
	char str[256];
	sprintf(str,"%d events   No cuts on primary conversion point.", fine->GetEntries(cut1));
	
	StandardLabels(axes, "100MeV #leq E #leq 150MeV  10^{o}#leq#theta#leq110^{o}", "Single #gamma", str, "RMS from projections");
	
	c1->SaveAs("theta_rms_vs_E.png");
	c1->SaveAs("theta_rms_vs_E.pdf");
}

TH1D* MakeRMSHisto(TH2D *h)
{
	char hname[256];
	sprintf(hname, "%s_2", h->GetName());
	
	TAxis *xaxis = h->GetXaxis();
	TAxis *yaxis = h->GetYaxis();
	Int_t Nbins = xaxis->GetNbins();
	TH1D *h_2 = new TH1D(hname, "", Nbins, xaxis->GetXmin(), xaxis->GetXmax());
	TH1D *tmp_py = new TH1D("tmp_py", "", yaxis->GetNbins(), yaxis->GetXmin(), yaxis->GetXmax());
	
	for(int bin=1; bin<=Nbins; bin++){
		tmp_py->Reset();
		h->ProjectionY("tmp_py", bin, bin);

		h_2->SetBinContent(bin, tmp_py->GetRMS());
		h_2->SetBinError(bin, tmp_py->GetRMSError());
	}
	
	return h_2;
}