X-Git-Url: https://git.sesse.net/?p=bursty;a=blobdiff_plain;f=summarize.pl;h=0b17e24d6025f90e312a5083f0f9663700b0484a;hp=545fa0e5bab3daecb2d3afad4b957c407f199844;hb=725ffec44d53ddad34062abf7ccf1a1e86e810dd;hpb=fc6f7214ed765c6a1f76d84136d52424e747925e

diff --git a/summarize.pl b/summarize.pl
index 545fa0e..0b17e24 100755
--- a/summarize.pl
+++ b/summarize.pl
@@ -3,6 +3,19 @@
 use strict;
 use warnings;
 
+sub wilson_interval {
+	my ($x, $n) = @_;
+	my $z = 1.96;  # 95% confidence interval
+
+	my $p = $x / $n;
+	my $min = ($p + $z * $z / (2 * $n) - $z * sqrt($p * (1 - $p) / $n + $z * $z / (4 * $n * $n))) / (1 + $z * $z / $n);
+	my $max = ($p + $z * $z / (2 * $n) + $z * sqrt($p * (1 - $p) / $n + $z * $z / (4 * $n * $n))) / (1 + $z * $z / $n);
+
+	$min = 0 if ($min < 0);
+
+	return ($min, $max);
+}
+
 my %buckets = ();
 
 while (<>) {
@@ -20,8 +33,18 @@ while (<>) {
 }
 
 for my $n (sort { $a <=> $b } keys %buckets) {
-	my $drop_rate = $buckets{$n}->{'num_drops'} / ($n * $buckets{$n}->{'num_bursts'});
-	my $drop_event_rate = $buckets{$n}->{'num_drops'} / ($n * $buckets{$n}->{'num_bursts'});
-	printf "%3d: drop_rate %.5f  drop_event_rate %.5f\n",
-		$n, $drop_rate, $drop_event_rate; 
+	my $num_bursts = $buckets{$n}->{'num_bursts'} // 0;
+	my $num_drops = $buckets{$n}->{'num_drops'} // 0;
+	my $bursts_with_drops = $buckets{$n}->{'bursts_with_drops'} // 0;
+
+	my $drop_rate = $num_drops / ($n * $num_bursts);
+	my $drop_event_rate = $bursts_with_drops / $num_bursts;
+
+	my ($drop_rate_min, $drop_rate_max) = wilson_interval($num_drops, $n * $num_bursts);
+	my ($drop_event_rate_min, $drop_event_rate_max) = wilson_interval($bursts_with_drops, $num_bursts);
+
+	printf "%3d: drop_rate %.5f  95%%ci = [%.5f, %.5f] (%4d/%8d)   drop_event_rate %.5f  95%%ci = [%.5f, %.5f] (%3d/%4d)\n",
+		$n,
+		$drop_rate, $drop_rate_min, $drop_rate_max, $num_drops, $n * $num_bursts,
+		$drop_event_rate, $drop_event_rate_min, $drop_event_rate_max, $bursts_with_drops, $num_bursts;
 }