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<html xmlns="http://www.w3.org/1999/xhtml">
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<title>matchers/median.pm</title>
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<link rev="made" href="mailto:dws@ee.ethz.ch" />
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<body style="background-color: white">
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<p><a name="__index__"></a></p>
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<li><a href="#name">NAME</a></li>
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<li><a href="#overview">OVERVIEW</a></li>
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<li><a href="#description">DESCRIPTION</a></li>
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<li><a href="#copyright">COPYRIGHT</a></li>
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<li><a href="#license">LICENSE</a></li>
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<li><a href="#author">AUTHOR</a></li>
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<h1><a name="name">NAME</a></h1>
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<p>matchers::median - Find persistant change in latency</p>
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<h1><a name="overview">OVERVIEW</a></h1>
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<p>The idea behind this matcher is to find sustained changes in latency.</p>
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<p>The median matcher takes a number of past median latencies. It splits the latencies into
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two groups (old and new) and again finds the median for each groups. If the
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difference between the two medians is bigger than a certain value, it will
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<h1><a name="description">DESCRIPTION</a></h1>
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<p>Call the matcher with the following sequence:</p>
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pattern = median(old=>x,new=>y,diff=>z)</pre>
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<p>This will create a matcher which consumes x+y latency-datapoints, builds the
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two medians and the matches if the difference between the median latency is
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larger than z seconds.</p>
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<h1><a name="copyright">COPYRIGHT</a></h1>
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<p>Copyright (c) 2004 by OETIKER+PARTNER AG. All rights reserved.</p>
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<h1><a name="license">LICENSE</a></h1>
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<p>This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.</p>
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<p>This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.</p>
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<p>You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.</p>
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<h1><a name="author">AUTHOR</a></h1>
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<p>Tobias Oetiker <<a href="mailto:tobi@oetiker.ch">tobi@oetiker.ch</a>></p>