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| -rw-r--r-- | CHANGES | 6 | ||||
| -rw-r--r-- | lib/Smokeping/RRDhelpers.pm | 91 |
2 files changed, 97 insertions, 0 deletions
@@ -1,3 +1,9 @@ +* Added stddev caclulation -- tobi + +* Added slave support into detail graphs -- tobi + +* Made interactive Graph zoomer somewhat work on ie6 and ie7 -- tobi + * Integrated interactive Graph zoomer -- Roman Plessl rplessl oetiker.ch * first drop of the master/slave code added. now the debugging beginns. -- tobi diff --git a/lib/Smokeping/RRDhelpers.pm b/lib/Smokeping/RRDhelpers.pm new file mode 100644 index 0000000..3f4fa5b --- /dev/null +++ b/lib/Smokeping/RRDhelpers.pm @@ -0,0 +1,91 @@ +# -*- perl -*- +package Smokeping::RRDhelpers; + +=head1 NAME + +Smokeping::RRDhelpers - Functions for doing 'interesting things' with RRDs. + +=head1 OVERVIEW + +This module holds a collection of functions for doing advanced calculations +and effects on rrd files. + +=cut + +use strict; +use RRDs; + +=head2 IMPLEMENTATION + +=head3 get_stddev(rrd,ds,cf,start,end[,step]) + +Pull the data values off the rrd file and calculate the standard deviation. Nan +values get ignored in this process. + +=cut + +sub get_stddev{ + my $rrd = shift; + my $ds = shift; + my $cf = shift; + my $start = shift; + my $end = shift; + my $step = shift; + my ($realstart,$realstep,$names,$array) = RRDs::fetch $rrd, $cf, '--start',$start, '--end',$end,($step ? ('--resolution',$step):()); + if (my $err = RRDs::error){ + warn $err + }; + my $idx = 0; + for (@$names){ + last if $ds eq $_; + $idx ++; + } + my $sum = 0; + my $sqsum = 0; + my $cnt = 0; + foreach my $line (@$array){ + my $val = $line->[$idx]; + if (defined $val){ + $cnt++; + $sum += $val; + $sqsum += $val**2; + } + } + return undef unless $cnt; + return sqrt( 1.0 / $cnt * ( $sqsum - $sum**2 / $cnt )) +} + + + +1; + +__END__ + +=head1 COPYRIGHT + +Copyright 2007 by Tobias Oetiker + +=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 E<lt>tobi@oetiker.chE<gt> + +=cut |