#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;

}