#!/usr/bin/perl
#
# avg.pl - read in a file of numbers and print out the average
#
# Usage: avg.pl [-i]
#             -i: print cumulative average every sample
#
# Michele C. Weigle, mweigle@cs.odu.edu
# Old Dominion University, November 2006

$output = 0;
if ($#ARGV == 0 && $ARGV[0] == "-i") {
  $output = 1;
}
elsif ($#ARGV == 0 && $ARGV[0] != "-i") {
  print "Usage: avg.pl [-i]\n";
  print "          -i: print cumulative average every sample\n";
  exit;
}

$sum = 0;
$count = 0;
while (<STDIN>) {
  chop $_;
  $sum += $_;
  $count++;
  if ($output) {
    printf ("%d %f\n", $count, $sum/$count);
  }
}
if ($count == 0) {
  print "No data read...\n";
  exit;
}
if (!$output) {
  printf ("%d %f\n", $count, $sum/$count);
}