00001 /* 00002 * StatisticalLimitFilter.cc : part of the Mace toolkit for building distributed systems 00003 * 00004 * Copyright (c) 2007, Charles Killian, Dejan Kostic, Ryan Braud, James W. Anderson, John Fisher-Ogden, Calvin Hubble, Duy Nguyen, Justin Burke, David Oppenheimer, Amin Vahdat, Adolfo Rodriguez, Sooraj Bhat 00005 * All rights reserved. 00006 * 00007 * Redistribution and use in source and binary forms, with or without 00008 * modification, are permitted provided that the following conditions are met: 00009 * 00010 * * Redistributions of source code must retain the above copyright 00011 * notice, this list of conditions and the following disclaimer. 00012 * * Redistributions in binary form must reproduce the above copyright 00013 * notice, this list of conditions and the following disclaimer in 00014 * the documentation and/or other materials provided with the 00015 * distribution. 00016 * * Neither the names of Duke University nor The University of 00017 * California, San Diego, nor the names of the authors or contributors 00018 * may be used to endorse or promote products derived from 00019 * this software without specific prior written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00022 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00023 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00024 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 00025 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00026 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 00027 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00028 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 00029 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 00030 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00031 * 00032 * ----END-OF-LEGAL-STUFF---- */ 00033 #include <math.h> 00034 #include "StatisticalLimitFilter.h" 00035 00036 using std::list; 00037 00038 StatisticalLimitFilter::StatisticalLimitFilter(int limit) 00039 : total(0), total_square(0), standard_deviation(0), measurements(0), 00040 keep_limit(limit) { 00041 } 00042 00043 StatisticalLimitFilter::~StatisticalLimitFilter() { 00044 } 00045 00046 void StatisticalLimitFilter::update(double incoming_value) { 00047 if (contents.size() > keep_limit) { 00048 contents.pop_front(); 00049 } 00050 contents.push_back(incoming_value); 00051 measurements = contents.size(); 00052 total = 0; 00053 total_square = 0; 00054 for(list<double>::iterator it = contents.begin(); 00055 it != contents.end(); ++it) { 00056 double incoming = *it; 00057 total += incoming; 00058 total_square += incoming * incoming; 00059 } 00060 standard_deviation = sqrt((total_square * measurements - (total * total)) / 00061 (measurements * (measurements - 1))); 00062 value = total / measurements; 00063 } 00064 00065 double StatisticalLimitFilter::getDeviation() { 00066 return standard_deviation; 00067 } 00068 00069 int StatisticalLimitFilter::getCount() { 00070 return contents.size(); 00071 } 00072 00073 int StatisticalLimitFilter::reset() { 00074 measurements = 0; 00075 value = 0; 00076 total = 0; 00077 total_square = 0; 00078 standard_deviation = 0; 00079 contents.clear(); 00080 return 0; 00081 }