1 #include <math.h>

     2 #include "histogram.h"

     3 #include "tcl_interface.h"

     4 

     5 void Histogram::initialize_mean()

     6 {

     7   int total_weight = 0;

     8   int i;

     9   for(i = 0; i < num_rows; i++)

    10     {

    11       total_weight = total_weight + row_weights[i];

    12     }

    13   mean = (double) total_weight / (double) num_rows;

    14 }

    15 

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

    17 

    18 void Histogram::initialize_variance()

    19 { 

    20   double sum = 0;

    21   for(int i = 0; i < num_rows; i++)

    22       {

    23 	sum += sqr(row_weights[i] - mean);

    24       }

    25   variance = (double) sum / (double) num_rows;

    26 }

    27 

    28 void Histogram::initialize_standard_dev()

    29 {

    30   standard_dev = sqrt(variance);

    31 }

    32 #define SKIP 5

    33 /* should get this skip from project.cc (!!) */

    34 Histogram::display()

    35 {

    36 #if 0

    37   docommand(".histogram.c delete hist");

    38   docommand(".histogram.c create text 275 300 -font -adobe-helvetica-medium-o-normal--34-240-100-100-p-176-iso8859-1 -text \"%.3lf degrees, SD = %.3lf\" -tags hist", cut_angle, standard_dev);

    39   for(int i = 0; i < num_rows; i++)

    40       {

    41 	docommand(".histogram.c create line 0 %d %d %d -fill blue -tags {hist} -width %d", i*SKIP, row_weights[i], i*SKIP, SKIP);

    42       }

    43   docommand("update");

    44 #endif

    45 }

    46 

    47 Histogram::Histogram(int n_rows, int* r_weights, double c_angle)

    48 {

    49   num_rows = n_rows;

    50   row_weights = r_weights;

    51   cut_angle = c_angle;

    52   initialize_mean();

    53   initialize_variance();

    54   initialize_standard_dev();

    55 }

    56 

    57 

    58 

    59 

    60 

    61 

    62 

    63 

    64 

    65 

    66 double find_int_sd(int* values, int num_values)

    67 /* find the standard deviation of an array of ints */

    68 {

    69   int total_weight = 0;

    70   int i;

    71   for(i = 0; i < num_values; i++)

    72     {

    73       total_weight = total_weight + values[i];

    74     }

    75   double mean_weight = (double) total_weight / (double) num_values;

    76   double standard_sum = 0;

    77   for(i = 0; i < num_values; i++)

    78     {

    79       standard_sum += sqr(values[i] - mean_weight);

    80     }

    81   standard_sum = standard_sum / (double) num_values;

    82   return sqrt(standard_sum);

    83 }

    84