MovingAverage.h

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/* Copyright (C) Cross The Road Electronics 2024 */
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 *  Software License Agreement
 *
 * Copyright (C) Cross The Road Electronics.  All rights
 * reserved.
 * 
 * Cross The Road Electronics (CTRE) licenses to you the right to 
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 * API Libraries ONLY when in use with Cross The Road Electronics hardware products.
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namespace ctre {
namespace phoenix {
namespace signals {
 
/**
 * Class to calculate the rolling average of a signal
 */
class MovingAverage {
private:
 
    int _in; //!< head ptr for ringbuffer
    int _ou; //!< tail ptr for ringbuffer
    int _cnt; //!< number of element in ring buffer
    int _cap; //!< capacity of ring buffer
    float _sum; //!< sum of all elements in ring buffer
    float * _d; //!< ring buffer
public:
    /**
     * Constructor for a MovingAverage Object
     * @param capacity maximum number of items this will hold
     */
    MovingAverage(int capacity) {
        _cap = capacity;
        _d = new float[_cap];
        Clear();
    }
    /**
     * Add input & calculate average
     * @param input Value to add
     * @return new average
     */
    float Process(float input) {
        Push(input);
        return _sum / (float) _cnt;
    }
    /**
     * Clears all data points
     */
    void Clear() {
        _in = 0;
        _ou = 0;
        _cnt = 0;
 
        _sum = 0;
    }
    /**
     * Add new item
     * @param d item to add
     */
    void Push(float d) {
        /* process it */
        _sum += d;
 
        /* if full, pop one */
        if (_cnt >= _cap)
            Pop();
 
        /* push new one */
        _d[_in] = d;
        if (++_in >= _cap)
            _in = 0;
        ++_cnt;
    }
    /**
     * Pull out oldest item
     */
    void Pop() {
        /* get the oldest */
        float d = _d[_ou];
 
        /* process it */
        _sum -= d;
 
        /* pop it */
        if (++_ou >= _cap)
            _ou = 0;
        --_cnt;
    }
    //-------------- Properties --------------//
    /**
     * @return the sum of the items
     */
    float GetSum() {
        return _sum;
    }
    /**
     * @return the count of the items
     */
    int GetCount() {
        return _cnt;
    }
};
 
} // namespace  Signals
} // namespace phoenix
} // namespace ctre