Filter.h

// Copyright (c) 2020 Institute for Automotive Engineering (ika), RWTH Aachen University. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// Created by Jens Klimke on 2020-04-04
// Contributors:
//


#ifndef SIMDRIVER_FILTER_H
#define SIMDRIVER_FILTER_H

#include <deque>
#include <vector>

namespace agent_model {


    class Filter {

    protected:

        unsigned int n; 
        unsigned int i; 

        std::vector<double> _elements; 

    public:

        void init(unsigned int length) {

            // set length and index
            n = length;
            i = 0;

            // create vector
            if (_elements.size() != n) {
                _elements.clear();
                _elements.reserve(n);
            }

        }


        double value() {

            // special case
            if(_elements.empty())
                return 0.0;

            // sum up
            auto sum = 0.0;
            for (auto &e : _elements)
                sum += e;

            // return average value
            return sum / (double) _elements.size();

        }


        double value(double v) {

            // add element
            if(_elements.size() < n)
                _elements.emplace_back(v);
            else
                _elements.at(i) = v;

            // increment i
            i = (i + 1) % n;

            // return mean value
            return value();

        }

    };


}


#endif // SIMDRIVER_FILTER_H