#include <TCanvas>

#include <RooRealVar.h>
#include <RooGenericPdf.h>
#include <RooPlot.h>

void problemDemo()
{
	RooRealVar x ("x", "invariant mass", 1100, 1800, "MeV^c{2}");
	RooRealVar E ("E", "center-of-mass energy", 2000, 2050, "MeV^c{2}");
	RooRealVar a ("a", "composition parameter a", 1, 1, 1);
	RooRealVar b ("b", "composition parameter b", 1, 1, 1);
	RooGenericPdf demo ("demo", "problem demo", "a*x^2*E + b*x^3/E", RooArgList(x, E, a, b));
	// Fit function to data...

	// Integrate complete function, i.e. x^2*E + x^3/E
	RooRealVar* intTotal = demo.createIntegral(RooArgSet(x, E));
	a.setRange(0.0, 1.0);
	b.setRange(0.0, 1.0);
	b.setVal(0.0);
	// Integrate only x^2*E
	RooRealVar* intA = demo.createIntegral(RooArgSet(x, E));
	a.setVal(0.0);
	b.setVal(1.0);
	// Integrate only x^3/E
	RooRealVar* intB = demo.createIntegral(RooArgSet(x, E));
	a.setVal(1.0);
	
	std::cout << "Total Integral: " << intTotal->getVal() << std::endl;
	std::cout << "A Integral: " << intA->getVal() << std::endl;
	std::cout << "B Integral: " << intB->getVal() << std::endl;
}