LibrePilot/ground/openpilotgcs/src/plugins/scope/plotdata.cpp

/**
 ******************************************************************************
 *
 * @file       plotdata.cpp
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @addtogroup GCSPlugins GCS Plugins
 * @{
 * @addtogroup ScopePlugin Scope Gadget Plugin
 * @{
 * @brief The scope Gadget, graphically plots the states of UAVObjects
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


#include "plotdata.h"
#include <math.h>
#include <QDebug>

PlotData::PlotData(UAVObject *object, UAVObjectField *field, int element,
                   QwtPlotCurve *plotCurve, int scaleOrderFactor, int meanSamples,
                   QString mathFunction, double plotDataSize) :
    m_scalePower(scaleOrderFactor), m_meanSamples(meanSamples),
    m_mathFunction(mathFunction), m_plotDataSize(plotDataSize),
    m_object(object), m_field(field),
    m_element(element), m_plotCurve(plotCurve)
{
    m_plotCurve->setSamples(m_xDataEntries, m_yDataEntries);

    if (!field->getElementNames().isEmpty()) {
        m_elementName = field->getElementNames().at(element);
    }
    m_meanSum         = 0.0f;
    m_correctionSum   = 0.0f;
    m_correctionCount = 0;
    m_yMin        = 0;
    m_yMax        = 0;
}

double PlotData::valueAsDouble(UAVObject *obj, UAVObjectField *field)
{
    Q_UNUSED(obj);
    QVariant value = field->getValue(m_element);
    return value.toDouble();
}

PlotData::~PlotData()
{
    m_plotCurve->detach();
    delete m_plotCurve;
}

void PlotData::updatePlotCurveData()
{
    m_plotCurve->setSamples(m_xDataEntries, m_yDataEntries);
}

void PlotData::calcMathFunction(double currentValue)
{
    // Put the new value at the back
    m_yDataHistory.append(currentValue);

    // calculate average value
    m_meanSum += currentValue;
    if (m_yDataHistory.size() > m_meanSamples) {
        m_meanSum -= m_yDataHistory.first();
        m_yDataHistory.pop_front();
    }
    // make sure to correct the sum every meanSamples steps to prevent it
    // from running away due to floating point rounding errors
    m_correctionSum += currentValue;
    if (++m_correctionCount >= m_meanSamples) {
        m_meanSum = m_correctionSum;
        m_correctionSum = 0.0f;
        m_correctionCount = 0;
    }

    double boxcarAvg = m_meanSum / m_yDataHistory.size();
    if (m_mathFunction == "Standard deviation") {
        // Calculate square of sample standard deviation, with Bessel's correction
        double stdSum = 0;
        for (int i = 0; i < m_yDataHistory.size(); i++) {
            stdSum += pow(m_yDataHistory.at(i) - boxcarAvg, 2) / (m_meanSamples - 1);
        }
        m_yDataEntries.append(sqrt(stdSum));
    } else {
        m_yDataEntries.append(boxcarAvg);
    }
}

bool SequentialPlotData::append(UAVObject *obj)
{
    if (m_object == obj) {
        if (m_field) {
            double currentValue = valueAsDouble(m_object, m_field) * pow(10, m_scalePower);

            // Perform scope math, if necessary
            if (m_mathFunction == "Boxcar average" || m_mathFunction == "Standard deviation") {
                calcMathFunction(currentValue);
            } else {
                m_yDataEntries.append(currentValue);
            }

            if (m_yDataEntries.size() > m_plotDataSize) {
                // If new data overflows the window, remove old data...
                m_yDataEntries.pop_front();
            } else {
                // ...otherwise, add a new y point at position xData
                m_xDataEntries.insert(m_xDataEntries.size(), m_xDataEntries.size());
            }

            return true;
        }
    }

    return false;
}

bool ChronoPlotData::append(UAVObject *obj)
{
    if (m_object == obj) {
        // Get the field of interest
        if (m_field) {
            QDateTime NOW = QDateTime::currentDateTime(); // THINK ABOUT REIMPLEMENTING THIS TO SHOW UAVO TIME, NOT SYSTEM TIME
            double currentValue = valueAsDouble(m_object, m_field) * pow(10, m_scalePower);

            // Perform scope math, if necessary
            if (m_mathFunction == "Boxcar average" || m_mathFunction == "Standard deviation") {
                calcMathFunction(currentValue);
            } else {
                m_yDataEntries.append(currentValue);
            }

            double valueX = NOW.toTime_t() + NOW.time().msec() / 1000.0;
            m_xDataEntries.append(valueX);

            // Remove stale data
            removeStaleData();
            return true;
        }
    }

    return false;
}

void ChronoPlotData::removeStaleData()
{
    double newestValue;
    double oldestValue;

    while (1) {
        if (m_xDataEntries.size() == 0) {
            break;
        }

        newestValue = m_xDataEntries.last();
        oldestValue = m_xDataEntries.first();

        if (newestValue - oldestValue > m_plotDataSize) {
            m_yDataEntries.pop_front();
            m_xDataEntries.pop_front();
        } else {
            break;
        }
    }

    // qDebug() << "removeStaleData ";
}

void ChronoPlotData::removeStaleDataTimeout()
{
    removeStaleData();
    // qDebug() << "removeStaleDataTimeout";
}