mean_filter.h

Go to the documentation of this file.

/******************************************************************************
 * Copyright 2017 The Apollo Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *****************************************************************************/

#pragma once

#include <cstdint>
#include <deque>
#include <utility>
#include <vector>

namespace apollo {
namespace common {

class MeanFilter {
 public:
  explicit MeanFilter(const std::uint_fast8_t window_size);
  MeanFilter() = default;
  ~MeanFilter() = default;
  double Update(const double measurement);

 private:
  void RemoveEarliest();
  void Insert(const double value);
  double GetMin() const;
  double GetMax() const;
  bool ShouldPopOldestCandidate(const std::uint_fast8_t old_time) const;
  std::uint_fast8_t window_size_ = 0;
  double sum_ = 0.0;
  std::uint_fast8_t time_ = 0;
  // front = earliest
  std::deque<double> values_;
  // front = min
  std::deque<std::pair<std::uint_fast8_t, double>> min_candidates_;
  // front = max
  std::deque<std::pair<std::uint_fast8_t, double>> max_candidates_;
  bool initialized_ = false;
};

}  // namespace common
}  // namespace apollo