TSlidingWindow.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

// Implementattion file for TSlidingWindow struct
#include "graphslam-precomp.h"  // Precompiled headers

#include <mrpt/config/CConfigFileBase.h>
#include <mrpt/serialization/CArchive.h>
#include <mrpt/graphslam/misc/TSlidingWindow.h>

#include <algorithm>
#include <numeric>

using namespace mrpt::graphslam;

TSlidingWindow::TSlidingWindow(std::string name /* = "window" */)
{
    MRPT_START;

    m_win_size = 5;  // just a default value
    m_name = name;

    m_mean_cached = 0;
    m_median_cached = 0;

    m_is_initialized = false;
    m_mean_updated = false;
    m_median_updated = false;
    m_std_dev_updated = false;

    MRPT_END;
}
TSlidingWindow::~TSlidingWindow() {}
double TSlidingWindow::getMedian()
{
    MRPT_START;

    double median_out = 0.0;
    if (m_measurements_vec.empty())
    {
        return 0.0;
    }

    if (m_median_updated)
    {
        median_out = m_median_cached;
    }
    else
    {
        // copy the current vector, sort it and return value in middle
        std::vector<double> vec_sorted(m_measurements_vec);
        std::sort(vec_sorted.begin(), vec_sorted.end());

        median_out = vec_sorted.at(vec_sorted.size() / 2);

        m_median_cached = median_out;
        m_median_updated = true;
    }

    return median_out;

    MRPT_END;
}
double TSlidingWindow::getMean()
{
    MRPT_START;

    double mean_out = 0.0;

    if (m_mean_updated)
    {
        mean_out = m_mean_cached;
    }
    else
    {
        mean_out = std::accumulate(
            m_measurements_vec.begin(), m_measurements_vec.end(), 0.0);
        mean_out /= m_measurements_vec.size();

        m_mean_cached = mean_out;
        m_mean_updated = true;
    }

    return mean_out;

    MRPT_END;
}
double TSlidingWindow::getStdDev()
{
    MRPT_START;

    double std_dev_out = 0.0;

    if (m_std_dev_updated)
    {  // return the cached version?
        std_dev_out = m_std_dev_cached;
    }
    else
    {
        double mean = this->getMean();

        double sum_of_sq_diffs = 0;
        for (std::vector<double>::const_iterator it =
                 m_measurements_vec.begin();
             it != m_measurements_vec.end(); ++it)
        {
            sum_of_sq_diffs += std::pow(*it - mean, 2);
        }
        std_dev_out = sqrt(sum_of_sq_diffs / m_win_size);

        m_std_dev_cached = std_dev_out;
        m_std_dev_updated = true;
    }

    return std_dev_out;
    MRPT_END;
}

bool TSlidingWindow::evaluateMeasurementInGaussian(double measurement)
{
    // get the boundaries for acceptance of measurements - [-3sigma, 3sigma]
    // with
    // regards to the mean
    double low_lim = this->getMean() - 3 * this->getStdDev();
    double upper_lim = this->getMean() + 3 * this->getStdDev();

    return measurement > low_lim && measurement < upper_lim;
}
bool TSlidingWindow::evaluateMeasurementAbove(double value)
{
    MRPT_START;

    double threshold = this->getMean();
    return (value > threshold);

    MRPT_END;
}
bool TSlidingWindow::evaluateMeasurementBelow(double value)
{
    return !evaluateMeasurementAbove(value);
}

void TSlidingWindow::addNewMeasurement(double measurement)
{
    MRPT_START;

    m_is_initialized = true;

    // if I haven't already filled up to win_size the vector, just add it
    if (m_win_size > m_measurements_vec.size())
    {
        m_measurements_vec.push_back(measurement);
    }
    else
    {
        // remove first element - add it as last element
        m_measurements_vec.erase(m_measurements_vec.begin());
        m_measurements_vec.push_back(measurement);
    }

    m_mean_updated = false;
    m_median_updated = false;
    m_std_dev_updated = false;

    MRPT_END;
}
void TSlidingWindow::resizeWindow(size_t new_size)
{
    MRPT_START;

    size_t curr_size = m_measurements_vec.size();
    if (new_size < curr_size)
    {
        // remove (curr_size - new_size) elements from the beginning of the
        // measurements vector
        m_measurements_vec.erase(
            m_measurements_vec.begin(),
            m_measurements_vec.begin() + (curr_size - new_size));

        m_mean_updated = false;
        m_median_updated = false;
    }

    m_win_size = new_size;

    MRPT_END;
}
void TSlidingWindow::loadFromConfigFile(
    const mrpt::config::CConfigFileBase& source, const std::string& section)
{
    MRPT_START;

    size_t sliding_win_size =
        source.read_int(section, "sliding_win_size", 10, false);
    this->resizeWindow(sliding_win_size);

    MRPT_END;
}
void TSlidingWindow::dumpToTextStream(std::ostream& out) const
{
    MRPT_START;

    out << mrpt::format(
        "-----------[ %s: Sliding Window Properties ]-----------\n",
        m_name.c_str());
    out << mrpt::format("Measurements Vector: \n");
    for (std::vector<double>::const_iterator it = m_measurements_vec.begin();
         it != m_measurements_vec.end(); ++it)
    {
        out << mrpt::format("\t%.2f\n", *it);
    }
    out << mrpt::format("\n");

    out << mrpt::format("m_name              : %s\n", m_name.c_str());
    out << mrpt::format("m_mean_cached       : %.2f\n", m_mean_cached);
    out << mrpt::format("m_median_cached     : %.2f\n", m_median_cached);
    out << mrpt::format("m_std_dev_cached    : %.2f\n", m_std_dev_cached);
    out << mrpt::format(
        "m_mean_updated      : %s\n", m_mean_updated ? "TRUE" : "FALSE");
    out << mrpt::format(
        "m_median_updated    : %s\n", m_median_updated ? "TRUE" : "FALSE");
    out << mrpt::format(
        "m_std_dev_updated   : %s\n", m_std_dev_updated ? "TRUE" : "FALSE");
    out << mrpt::format("m_win_size          : %lu\n", m_win_size);
    out << mrpt::format(
        "m_is_initialized    : %s\n", m_is_initialized ? "TRUE" : "FALSE");

    MRPT_END;
}

size_t TSlidingWindow::getWindowSize() const { return m_win_size; }
bool TSlidingWindow::windowIsFull() const
{
    return (m_win_size == m_measurements_vec.size());
}