/*
 * Chi2Estimator.cxx
 *
 *  Created on: Jun 5, 2013
 *      Author: steve
 */

#include "Chi2Estimator.h"
#include "core/Model.h"
#include "fit/data/Data.h"

#include <iostream>

Chi2Estimator::Chi2Estimator() {
	// TODO Auto-generated constructor stub
}

Chi2Estimator::~Chi2Estimator() {
	// TODO Auto-generated destructor stub
}

double Chi2Estimator::eval() const {
	//calculate chisquare
	double chisq = 0.0;
	double delta;

	std::vector<DataPointProxy> &data_points = data->getData();
	// loop over data
	for (unsigned int i = 0; i < data_points.size(); i++) {
		shared_ptr<DataStructs::binned_data_point> data_point;
		if (data_points[i].isPointUsed()) {
			data_point = data_points[i].getBinnedDataPoint();
			delta =
					(data_point->z
							- data->getBinningFactor()
									* fit_model->evaluate(
											data_point->bin_center_value));
			double weightsquare = data_point->z_error * data_point->z_error;
			double modelweight = 0.0;
		/*	if (delta > 0.0) {
				modelweight += data->getBinningFactor()
						* fit_model->getUncertaincy(
								data_point->bin_center_value).second; // take upper error of model (second)
			} else {
				modelweight += data->getBinningFactor()
						* fit_model->getUncertaincy(
								data_point->bin_center_value).first; // take lower error of model (first)
			}
			weightsquare += modelweight * modelweight;*/
			chisq += delta * delta / weightsquare;
		}
	}
	return chisq;
}