JKQtPlotter/test/jkqtplotter_simpletest_dateaxes/jkqtplotter_simpletest_dateaxes.cpp

#include <QApplication>
#include <QDateTime>
#include <QTime>
#include <QFile>
#include <QTextStream>
#include "jkqtplotter/jkqtplotter.h"
#include "jkqtplotter/jkqtpgeoelements.h"
#include "jkqtplottertools/jkqtptools.h"

void drawWithDateAxis(JKQtPlotter& plot) {

    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
    JKQTPdatastore* ds=plot.getDatastore();

    // 2. now we create data vectors with data parsed from a CSV-file
    QVector<double> date;
    QVector<double> temperature, temperature_min, temperature_max;
    // parse a textfile with comments on the first line and the
    // semicolon separated data. The first column is a date and time
    // the second to fourth columns contain a floating-point number
    // with temperature average, min and max
    QFile file(":/weatherdata_gelsenkirchen.csv");
    file.open(QFile::ReadOnly|QFile::Text);
    file.readLine(); // eat comment
    while (!file.atEnd()) {
        QString line=file.readLine();
        QTextStream in(&line);
        QStringList items=line.split(";");
        // date/time values are stored as doubles representing the corresponding number of milliseconds sind epoch
        date<<QDateTime::fromString(items[0], Qt::ISODate).toUTC().toMSecsSinceEpoch();
        // store Heidelbergs daily temperature
        temperature<<items[1].toDouble();
        temperature_min<<items[2].toDouble();
        temperature_max<<items[3].toDouble();
    }

    // 3. add a plot for the data mean line (graphTemperature) and range (graphTemperatureRange)
    JKQTPfilledVerticalRangeGraph* graphTemperatureRange=new JKQTPfilledVerticalRangeGraph(&plot);
    JKQTPxyLineErrorGraph* graphTemperature=new JKQTPxyLineErrorGraph(&plot);

    // 4. copy data into datastore and immediately set the yColumn
    size_t colDate=ds->addCopiedColumn(date, "date");
    graphTemperature->set_xColumn(colDate);
    graphTemperature->set_yColumn(ds->addCopiedColumn(temperature, "temperature"));
    graphTemperatureRange->set_xColumn(colDate);
    graphTemperatureRange->set_yColumn(ds->addCopiedColumn(temperature_min, "temperature_min"));
    graphTemperatureRange->set_yColumn2(ds->addCopiedColumn(temperature_max, "temperature_max"));


    // 5. min/max range data
    // graph fill color is a lighter shade of the average graph
    graphTemperatureRange->set_fillColor(graphTemperature->get_color().lighter());
    // don't draw lines of the data
    graphTemperatureRange->set_drawLine(false);
    // plot label in key
    graphTemperatureRange->set_title("Min/Max Temperature");
    // add the graph to the plot, so it is actually displayed
    plot.addGraph(graphTemperatureRange);

    // 6. average data
    // don't use symbols
    graphTemperature->set_symbol(JKQTPnoSymbol);
    // set the line width
    graphTemperature->set_lineWidth(1);
    // draw small symbols
    graphTemperature->set_symbolSize(6);
    // graph title
    graphTemperature->set_title("Average Temperature");
    // add the graph to the plot, so it is actually displayed
    plot.addGraph(graphTemperature);


    // 7. format the plot
    // set the title above the plot, use LaTeX instructions to make text bold
    plot.get_plotter()->set_plotLabel("\\textbf{Weather in Gelsenkirchen, 2017-2018}");
    // set x-axis date-time-axis
    plot.getXAxis()->set_labelType(JKQTPCALTdatetime);
    plot.getXAxis()->set_axisLabel("Date");
    // set format string for date axis (e.g. Jan '18), see Documentation of QDateTime::toString()
    plot.getXAxis()->set_tickDateTimeFormat("MMM ''yy");
    // set y-axis temperature axis
    plot.getYAxis()->set_axisLabel("Average Daily Temperature [{\\degree}C]");

    // 8. autoscale the plot so the graph is contained
    plot.zoomToFit();

    // 9. show plotter and make it a decent size
    plot.show();
    plot.resize(600,400);
    plot.setWindowTitle("Date Axis");
}

void drawWithTimeAxis(JKQtPlotter& plot) {
    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
    JKQTPdatastore* ds=plot.getDatastore();

    // 2. now we create data vectors with data parsed from a CSV-file
    QVector<double> time;
    QVector<double> temperature;
    // parse a textfile with comments on the first line and the
    // semicolon separated data. The first column is a time
    // the second contain a floating-point number with temperatures
    QFile file(":/weatherdata_heidelberg_2018-10-14.csv");
    file.open(QFile::ReadOnly|QFile::Text);
    file.readLine(); // eat comment
    while (!file.atEnd()) {
        QString line=file.readLine();
        QTextStream in(&line);
        QStringList items=line.split(";");
        // date/time values are stored as doubles representing the corresponding
        // number of milliseconds sind epoch. Since the data is time only, we have to use an arbitrary
        // date as basis
        time<<QDateTime::fromString("1970-01-01T"+items[0], Qt::ISODate).toMSecsSinceEpoch();
        // store Heidelbergs daily temperature
        temperature<<items[1].toDouble();
    }

    // 3. add a plot for the data mean line (graphTemperature) and range (graphTemperatureRange)
    JKQTPxyLineErrorGraph* graphTemperature=new JKQTPxyLineErrorGraph(&plot);

    // 4. copy data into datastore and immediately set the yColumn
    size_t colDate=ds->addCopiedColumn(time, "time");
    graphTemperature->set_xColumn(colDate);
    graphTemperature->set_yColumn(ds->addCopiedColumn(temperature, "temperature"));


    // 6. average data
    // don't use symbols
    graphTemperature->set_symbol(JKQTPcross);
    // set the line width
    graphTemperature->set_lineWidth(1);
    // draw small symbols
    graphTemperature->set_symbolSize(6);
    // graph title
    graphTemperature->set_title("Average Temperature");
    // add the graph to the plot, so it is actually displayed
    plot.addGraph(graphTemperature);


    // 7. format the plot
    // set the title above the plot, use LaTeX instructions to make text bold
    plot.get_plotter()->set_plotLabel("\\textbf{Weather in Heidelberg, 14^{th} Oct 2018}");
    // set x-axis date-time-axis
    plot.getXAxis()->set_labelType(JKQTPCALTtime);
    plot.getXAxis()->set_axisLabel("Time of Day");
    // set format string for time axis with 24-hour and minute only,
    // see QDateTime::toString() documentation for details on format strings
    plot.getXAxis()->set_tickTimeFormat("HH:mm");
    // set y-axis temperature axis
    plot.getYAxis()->set_axisLabel("Temperature [{\\degree}C]");

    // 8. autoscale the plot so the graph is contained
    plot.zoomToFit();

    // 9. show plotter and make it a decent size
    plot.show();
    plot.resize(600,400);
    plot.setWindowTitle("Time Axis");
}

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    JKQtPlotter plotDate;
    drawWithDateAxis(plotDate);
    plotDate.move(100,100);
    JKQtPlotter plotTime;
    drawWithTimeAxis(plotTime);
    plotTime.move(100,550);

    return app.exec();
}