#include "Histogram.h"
#include <math.h>

inline double sqr(double x) {return(x*x);}

void Histogram::calc_mean()
{
	int total_weight = 0;
	int i;
	for(i = 0; i < rows; i++)
		total_weight = total_weight + weights[i];
	mean = (double) total_weight / (double) rows;
}

void Histogram::calc_variance()
{
	double sum = 0;
	for(int i = 0; i < rows; i++)
		sum += sqr(weights[i] - mean);
	variance = (double) sum / (double) rows;
}

void Histogram::calc_std_dev()
{
	std_dev = sqrt(variance);
}

void Histogram::calcStatistics()
{
	calc_mean();
	calc_variance();
	calc_std_dev();
}

Histogram::Histogram(int numrows)
{
	rows = numrows;
	weights = new int[numrows];
}

Histogram::~Histogram()
{
	delete[] weights;
}