#!/bin/sh

if [ $# -eq 0 ]
then
    echo " "
    echo "Usage  : $0  column-no datafile "
    echo "By Michalis Faloutsos 1998"
    exit 1
fi

## Calculate the condifence interval of the 
## column $COLUMN which is passed as a parameter
awk 'BEGIN {
	## summ the round trip delay
	# COLUMN = 1
	max = 0
	min = 999999999.0
	count = 0
	sum_2 = 0
	sum = 0
}
{
  entry = $COLUMN
  if ( entry != 0) {
	count++
	sum += entry
	sum2 += entry * entry
	if (entry > max) {
		max = entry
	}
	if (entry < min) {
		min = entry
	}
  }
}
END{
if( count > 1)
 {
	avg = sum/count

        sigma2 = (sum2 - count * avg * avg) / (count -1)

	printf ("SAMPLES: %.1f ", count) 
	printf ("AVERAGE: %.3f ", avg) 
	printf ("S^2: %.3f  ",  sigma2) 
	sigma = sqrt(sigma2)
	printf ("S: %.3f \n", sigma) 
        ### Find in table for t distribution
        ### n = samples , g = 0.5/2 for 95 Conf Interval
	Tng = 2.02  
	delta = Tng * sigma / sqrt(count -1)
	printf ("d: %.3f ", delta) 
	printf ("FINAL 95-Inter: %.3f ", 2*delta) 
	printf ("d/Avg PERCENTAGE: %.3f ", delta/avg) 
	printf ("\n");
 }  ## if count > 1
print " >>>> Exclude zero entries <<<<"
print "min: ", min, "max: ", max, "  count: ", count
}' COLUMN=$1 $2