Arbitrary XY Line Chart

The following is the command line version of the code in "cppdemo/xyline". The MFC version of the code is in "mfcdemo/mfcdemo". The Qt Widgets version of the code is in "qtdemo/qtdemo". The QML/Qt Quick version of the code is in "qmldemo/qmldemo".
#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The (x, y) data for the first line
    double dataX0[] = {20, 90, 40, 30, 12};
    const int dataX0_size = (int)(sizeof(dataX0)/sizeof(*dataX0));
    double dataY0[] = {10, 40, 75, 54, 20};
    const int dataY0_size = (int)(sizeof(dataY0)/sizeof(*dataY0));

    // The (x, y) data for the second line
    double dataX1[] = {10, 40, 75, 54, 60};
    const int dataX1_size = (int)(sizeof(dataX1)/sizeof(*dataX1));
    double dataY1[] = {50, 90, 40, 30, 10};
    const int dataY1_size = (int)(sizeof(dataY1)/sizeof(*dataY1));

    // Create a XYChart object of size 450 x 450 pixels
    XYChart* c = new XYChart(450, 450);

    // Set the plotarea at (55, 65) and of size 350 x 300 pixels, with white background and a light
    // grey border (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color
    // (0xc0c0c0)
    c->setPlotArea(55, 65, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1);

    // Add a legend box at (50, 30) (top of the chart) with horizontal layout. Use 12pt Times Bold
    // Italic font. Set the background and border color to Transparent.
    c->addLegend(50, 30, false, "Times New Roman Bold Italic", 12)->setBackground(Chart::Transparent
        );

    // Add a title to the chart using 18pt Times Bold Itatic font
    c->addTitle("Reaction Path", "Times New Roman Bold Italic", 18);

    // Add a title to the y axis using 12pt Arial Bold Italic font
    c->yAxis()->setTitle("Temperature (Celcius)", "Arial Bold Italic", 12);

    // Set the y axis line width to 3 pixels
    c->yAxis()->setWidth(3);

    // Add a title to the x axis using 12pt Arial Bold Italic font
    c->xAxis()->setTitle("Pressure (Pa)", "Arial Bold Italic", 12);

    // Set the x axis line width to 3 pixels
    c->xAxis()->setWidth(3);

    // Add a red (0xff3333) line layer using dataX0 and dataY0
    LineLayer* layer1 = c->addLineLayer(DoubleArray(dataY0, dataY0_size), 0xff3333, "Compound AAA");
    layer1->setXData(DoubleArray(dataX0, dataX0_size));

    // Set the line width to 3 pixels
    layer1->setLineWidth(3);

    // Use 9 pixel square symbols for the data points
    layer1->getDataSet(0)->setDataSymbol(Chart::SquareSymbol, 9);

    // Add custom text labels to the first and last point on the scatter plot using Arial Bold font
    layer1->addCustomDataLabel(0, 0, "Start", "Arial Bold");
    layer1->addCustomDataLabel(0, 4, "End", "Arial Bold");

    // Add a green (0x33ff33) line layer using dataX1 and dataY1
    LineLayer* layer2 = c->addLineLayer(DoubleArray(dataY1, dataY1_size), 0x33ff33, "Compound BBB");
    layer2->setXData(DoubleArray(dataX1, dataX1_size));

    // Set the line width to 3 pixels
    layer2->setLineWidth(3);

    // Use 11 pixel diamond symbols for the data points
    layer2->getDataSet(0)->setDataSymbol(Chart::DiamondSymbol, 11);

    // Add custom text labels to the first and last point on the scatter plot using Arial Bold font
    layer2->addCustomDataLabel(0, 0, "Start", "Arial Bold");
    layer2->addCustomDataLabel(0, 4, "End", "Arial Bold");

    // Output the chart
    c->makeChart("xyline.png");

    //free up resources
    delete c;

    return 0;
}