1 #include "Histogram.h"

     2 #include <math.h>

     3 

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

     5 

     6 void Histogram::calc_mean()

     7 {

     8 	int total_weight = 0;

     9 	int i;

    10 	for(i = 0; i < rows; i++)

    11 		total_weight = total_weight + weights[i];

    12 	mean = (double) total_weight / (double) rows;

    13 }

    14 

    15 void Histogram::calc_variance()

    16 {

    17 	double sum = 0;

    18 	for(int i = 0; i < rows; i++)

    19 		sum += sqr(weights[i] - mean);

    20 	variance = (double) sum / (double) rows;

    21 }

    22 

    23 void Histogram::calc_std_dev()

    24 {

    25 	std_dev = sqrt(variance);

    26 }

    27 

    28 void Histogram::calcStatistics()

    29 {

    30 	calc_mean();

    31 	calc_variance();

    32 	calc_std_dev();

    33 }

    34 

    35 Histogram::Histogram(int numrows)

    36 {

    37 	rows = numrows;

    38 	weights = new int[numrows];

    39 }

    40 

    41 Histogram::~Histogram()

    42 {

    43 	delete[] weights;

    44 }