GoldenCheetah/src/StressCalculator.cpp

#include "StressCalculator.h"
#include "MetricAggregator.h"
#include "RideMetric.h"
#include "RideItem.h"
#include "MainWindow.h"

#include <stdio.h>

#include <QSharedPointer>
#include <QProgressDialog>

StressCalculator::StressCalculator (
	QDateTime startDate,
	QDateTime endDate,
        double initialSTS = 0,
	double initialLTS = 0,
	int shortTermDays = 7,
	int longTermDays = 42) :
	startDate(startDate), endDate(endDate), shortTermDays(shortTermDays),
	longTermDays(longTermDays),
	initialSTS(initialSTS), initialLTS(initialLTS), lastDaysIndex(-1)
{
    // calc SB for today or tomorrow?
    settings = GetApplicationSettings();
    showSBToday = settings->value(GC_SB_TODAY).toInt();

    days = startDate.daysTo(endDate);

    // make vectors 1 larger in case there is a ride for today.
    // see calculateStress()
    stsvalues.resize(days+2);
    ltsvalues.resize(days+2);
    sbvalues.resize(days+2);
    xdays.resize(days+2);
    list.resize(days+2);
    ltsramp.resize(days+2);
    stsramp.resize(days+2);

    lte = (double)exp(-1.0/longTermDays);
    ste = (double)exp(-1.0/shortTermDays);
}


double StressCalculator::max(void) {
    double max = 0.0;
    for(int i = 0; i < days; i++) {
	if (stsvalues[i] > max)  max = stsvalues[i];
	if (ltsvalues[i] > max)  max = ltsvalues[i]; // unlikely..
	if (sbvalues[i] > max)  max = sbvalues[i]; // really unlikely.
    }
    return max;
}


double StressCalculator::min(void) {
    double min = 100.0;
    for(int i = 0; i < days; i++) {
	if (sbvalues[i] < min)  min = sbvalues[i];
	if (ltsvalues[i] < min)  min = ltsvalues[i]; // unlikely..
	if (stsvalues[i] < min)  min = stsvalues[i]; // really unlikely
    }
    return min;
}



void StressCalculator::calculateStress(MainWindow *main, QString home, const QString &metric)
{
    // refresh metrics
    metricDB = new MetricAggregator(main, home, main->zones());

    // get all metric data from the year 1900 - 3000
    QList<SummaryMetrics> results;
    results = metricDB->getAllMetricsFor(QDateTime(QDate(1900,1,1)), QDateTime(QDate(3000,1,1)));

    // set start and enddate to maximum maximum required date range
    // remember the date range required so we can truncate afterwards
    QDateTime startDateNeeded = startDate;
    QDateTime endDateNeeded   = endDate;
    startDate = startDate < results[0].getRideDate() ? startDate : results[0].getRideDate();
    endDate   = endDate > results[results.count()-1].getRideDate() ? endDate : results[results.count()-1].getRideDate();

    int maxarray = startDate.daysTo(endDate) +2; // from zero plus tomorrows SB!
    stsvalues.resize(maxarray);
    ltsvalues.resize(maxarray);
    sbvalues.resize(maxarray);
    xdays.resize(maxarray);
    list.resize(maxarray);
    ltsramp.resize(maxarray);
    stsramp.resize(maxarray);

    for (int i=0; i<results.count(); i++)
        addRideData(results[i].getForSymbol(metric), results[i].getRideDate());

    // ensure the last day is covered ...
    addRideData(0.0, endDate);

    // now truncate the data series to the requested date range
    int firstindex = startDate.daysTo(startDateNeeded);
    int lastindex  = startDate.daysTo(endDateNeeded)+2; // for today and tomorrow SB

    // zap the back
    if (lastindex < maxarray) {
        stsvalues.remove(lastindex, maxarray-lastindex);
        ltsvalues.remove(lastindex, maxarray-lastindex);
        sbvalues.remove(lastindex, maxarray-lastindex);
        xdays.remove(lastindex, maxarray-lastindex);
        list.remove(lastindex, maxarray-lastindex);
        stsramp.remove(lastindex, maxarray-lastindex);
        ltsramp.remove(lastindex, maxarray-lastindex);
    }
    // now zap the front
    if (firstindex) {
        stsvalues.remove(0, firstindex);
        ltsvalues.remove(0, firstindex);
        ltsramp.remove(0, firstindex);
        stsramp.remove(0, firstindex);
        sbvalues.remove(0, firstindex);
        xdays.remove(0, firstindex);
        list.remove(0, firstindex);
    }

    // reapply the requested date range
    startDate = startDateNeeded;
    endDate = endDateNeeded;

    days = startDate.daysTo(endDate) + 1; // include today

    // will close the connection, alledgedly
    delete metricDB;
}

/*
 * calculate each day's STS and LTS.  The daily BS values are in
 * the list.  if there aren't enough days in the list yet, we fake
 * the missing days using the supplied initial value for each day.
 * STS and LTS are calculated up to but not including todays' ride.
 * if there are two rides per day the second one is added to the first
 * so the BS/day is correct.
 */
void StressCalculator::addRideData(double BS, QDateTime rideDate) {
    int daysIndex = startDate.daysTo(rideDate);

    // fill in any missing days before today
    int d;
    for (d = lastDaysIndex + 1; d < daysIndex ; d++) {
        list[d] = 0.0; // no ride
        calculate(d);
    }

    // ignore stuff from before start date
    if(daysIndex < 0) return;

    // today
    list[daysIndex] += BS;
    calculate(daysIndex);
    lastDaysIndex = daysIndex;
}


/*
 * calculate stress (in Bike Score units) using
 * stress = today's BS * (1 - exp(-1/days)) + yesterday's stress * exp(-1/days)
 * where days is the time period of concern- 7 for STS and 42 for LTS.
 *
 * exp(-1/days) for short and long term is calculated when the
 * class is instantiated.
 *
 */
void StressCalculator::calculate(int daysIndex) {
    double lastLTS, lastSTS;

    // LTS
    if (daysIndex == 0)
        lastLTS = initialLTS;
    else
        lastLTS = ltsvalues[daysIndex-1];

    ltsvalues[daysIndex] = (list[daysIndex] * (1.0 - lte)) + (lastLTS * lte);

    // STS
    if (daysIndex == 0)
        lastSTS = initialSTS;
    else
        lastSTS = stsvalues[daysIndex-1];

    stsvalues[daysIndex] = (list[daysIndex] * (1.0 - ste)) + (lastSTS * ste);

    // SB (stress balance)  long term - short term
    // XXX FIXED BUG WHERE SB WAS NOT SHOWN ON THE NEXT DAY!
    if (daysIndex == 0) sbvalues[daysIndex]=0;
    sbvalues[daysIndex+(showSBToday ? 0 : 1)] =  ltsvalues[daysIndex] - stsvalues[daysIndex] ;

    // xdays
    xdays[daysIndex] = daysIndex+1;

    // ramp
    if (daysIndex > 0) {
        stsramp[daysIndex] = stsvalues[daysIndex] - stsvalues[daysIndex-1];
        ltsramp[daysIndex] = ltsvalues[daysIndex] - ltsvalues[daysIndex-1];
    }
}