90 lines
1.8 KiB
C++
90 lines
1.8 KiB
C++
/*
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* © Copyright 2014 – Urheberrechtshinweis
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* Alle Rechte vorbehalten / All Rights Reserved
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*
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* Programmcode ist urheberrechtlich geschuetzt.
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* Das Urheberrecht liegt, soweit nicht ausdruecklich anders gekennzeichnet, bei Frank Ebner.
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* Keine Verwendung ohne explizite Genehmigung.
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* (vgl. § 106 ff UrhG / § 97 UrhG)
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*/
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#ifndef MOVINGMEDIANTS_H
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#define MOVINGMEDIANTS_H
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#include <vector>
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#include <algorithm>
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#include "../data/Timestamp.h"
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template <typename T> class MovingMedianTS {
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private:
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/** timestamp -> value combination */
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struct Entry {
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Timestamp ts;
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T value;
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Entry(const Timestamp ts, const T& value) : ts(ts), value(value) {;}
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};
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/** the regional window to use */
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Timestamp window;
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/** the value history for the window-size */
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std::vector<Entry> history;
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public:
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/** default ctor with zero window-size */
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MovingMedianTS() : window(Timestamp::fromMS(0)) {
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}
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/** ctor with the window-size to use */
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MovingMedianTS(const Timestamp window) : window(window) {
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}
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/** add a new value */
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void add(const Timestamp ts, const T data) {
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// append to history
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history.push_back(Entry(ts, data));
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// remove too-old history entries
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const Timestamp oldest = ts - window;
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while(history.front().ts < oldest) {
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// remove from history
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history.erase(history.begin());
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}
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}
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/** get the current median */
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T get() const {
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const auto comp = [] (const Entry& a, const Entry& b) {
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return a.value < b.value;
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};
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// create a sorted copy (slow, but works)
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std::vector<Entry> copy = history;
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std::sort(copy.begin(), copy.end(), comp);
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// get the median
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if (copy.size() % 2 != 0) {
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return copy[(copy.size() + 0) / 2].value;
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} else {
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return (copy[copy.size() / 2 - 1].value + copy[copy.size() / 2 + 0].value) / 2;
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}
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}
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};
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#endif // MOVINGMEDIANTS_H
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