--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/reference/ocr-simple/histogram.cc	Thu May 18 23:12:51 2006 +0200
@@ -0,0 +1,84 @@
+#include <math.h>
+#include "histogram.h"
+#include "tcl_interface.h"
+
+void Histogram::initialize_mean()
+{
+  int total_weight = 0;
+  int i;
+  for(i = 0; i < num_rows; i++)
+    {
+      total_weight = total_weight + row_weights[i];
+    }
+  mean = (double) total_weight / (double) num_rows;
+}
+
+inline double sqr(double x) {return(x*x);}
+
+void Histogram::initialize_variance()
+{ 
+  double sum = 0;
+  for(int i = 0; i < num_rows; i++)
+      {
+	sum += sqr(row_weights[i] - mean);
+      }
+  variance = (double) sum / (double) num_rows;
+}
+
+void Histogram::initialize_standard_dev()
+{
+  standard_dev = sqrt(variance);
+}
+#define SKIP 5
+/* should get this skip from project.cc (!!) */
+Histogram::display()
+{
+#if 0
+  docommand(".histogram.c delete hist");
+  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);
+  for(int i = 0; i < num_rows; i++)
+      {
+	docommand(".histogram.c create line 0 %d %d %d -fill blue -tags {hist} -width %d", i*SKIP, row_weights[i], i*SKIP, SKIP);
+      }
+  docommand("update");
+#endif
+}
+
+Histogram::Histogram(int n_rows, int* r_weights, double c_angle)
+{
+  num_rows = n_rows;
+  row_weights = r_weights;
+  cut_angle = c_angle;
+  initialize_mean();
+  initialize_variance();
+  initialize_standard_dev();
+}
+
+
+
+
+
+
+
+
+
+
+double find_int_sd(int* values, int num_values)
+/* find the standard deviation of an array of ints */
+{
+  int total_weight = 0;
+  int i;
+  for(i = 0; i < num_values; i++)
+    {
+      total_weight = total_weight + values[i];
+    }
+  double mean_weight = (double) total_weight / (double) num_values;
+  double standard_sum = 0;
+  for(i = 0; i < num_values; i++)
+    {
+      standard_sum += sqr(values[i] - mean_weight);
+    }
+  standard_sum = standard_sum / (double) num_values;
+  return sqrt(standard_sum);
+}
+