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diff --git a/lib/Smokeping/sorters/StdDev.pm b/lib/Smokeping/sorters/StdDev.pm
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+++ b/lib/Smokeping/sorters/StdDev.pm
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+package Smokeping::sorters::StdDev;
+
+=head1 NAME
+
+Smokeping::sorters::StdDev - Order the target charts by StdDev
+
+=head1 OVERVIEW
+
+Find the charts with the highest standard deviation among the Pings sent to
+a single target. The more smoke - higher the standard deviation.
+
+=head1 DESCRIPTION
+
+Call the sorter in the charts section of the config file
+
+ + charts
+  menu = Charts
+  title = The most interesting destinations
+
+ ++ stddev
+  sorter = StdDev(entries=>4)
+  title = Top StdDev
+  menu = Std Deviation
+  format = Stdandard Deviation %f
+
+=head1 COPYRIGHT
+
+Copyright (c) 2007 by OETIKER+PARTNER AG. All rights reserved.
+
+=head1 LICENSE
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+=head1 AUTHOR
+
+Tobias Oetiker <tobi@oetiker.ch>
+
+=cut
+
+use strict;
+use base qw(Smokeping::sorters::base);
+use vars qw($VERSION);
+$VERSION = 1.0;
+use Carp;
+
+# how many values does the matcher need to do it's magic
+
+sub new(@) {
+    my $class = shift;
+    my $rules = {
+        entries => '\d+'
+    };
+    my $self = $class->SUPER::new( $rules, @_ );
+    return $self;
+}
+
+sub Desc ($) {
+    return "The Standard Deviation sorter sorts the targets by Standard Deviation.";
+}    
+
+sub CalcValue($) {
+    my $self = shift;
+    my $info = shift;
+    # $info = { uptime => w,
+    #           loss   => x,
+    #           median => y,
+    #           alert  => z, (0/1)
+    #           pings  => [qw(a b c d)]
+    #
+    my $avg = 0;
+    my $cnt = 0;
+    my @values = grep { defined $_ } @{$info->{pings}};
+    for (@values){ $avg += $_; $cnt++};
+    return -1 if $cnt == 0;
+    $avg = $avg / $cnt;
+    my $dev = 0;
+    for (@values){ $dev += ($_ - $avg)**2};
+    $dev = sqrt($dev / $cnt);
+    return $dev;
+}