JKQtPlotter/examples/paramscatterplot_customsymbol/paramscatterplot_customsymbol.cpp

/** \example scatter_customsymbol.cpp
 * Usage of JKQTPScatterGraph with custom symbols
 *
 * \ref JKQTPlotterscatterCustomSymbol
 */
 
#include "jkqtpexampleapplication.h"
#include <QApplication>
#include "jkqtplotter/jkqtplotter.h"
#include "jkqtplotter/graphs/jkqtpscatter.h"
#include "jkqtpexampleapplication.h"
#include <random>

int main(int argc, char* argv[])
{

    JKQTPAppSettingController highDPIController(argc,argv);
    JKQTPExampleApplication app(argc, argv);


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

    // 2. add three columns to the JKQTPDatastore and obtain back-inserter iterators for these
    size_t columnX=ds->addColumn("x");
    auto colXInserter=ds->backInserter(columnX);
    size_t columnY=ds->addColumn("y");
    auto colYInserter=ds->backInserter(columnY);
    size_t columnS=ds->addColumn("sym");
    auto colSInserter=ds->backInserter(columnS);

    // 3. now we define a functor that draws a pie chart with three segments with fractions
    //    f1 (blue), f2 (green) and 1-f1-f2 (yellow)
    auto pieFunc=[](QPainter& p, double f1, double f2) {
            double f3=1.0-f1-f2;
            QRectF rec(-0.5,-0.5,1,1);
            p.setPen(QPen(QColor("black"), p.pen().width(), Qt::SolidLine));
            p.setBrush(QBrush(QColor("blue")));
            p.drawPie(rec, 90, -f1*360*16);
            p.setBrush(QBrush(QColor("green")));
            p.drawPie(rec, 90-f1*360*16, -f2*360*16);
            p.setBrush(QBrush(QColor("yellow")));
            p.drawPie(rec, 90-(f1+f2)*360*16, -f3*360*16);
        };
    // 4. now we create data for the plot, x and y follow a simple function
    //    and the symbols are encoded in a separated column, where for each datapoint, we
    //    register a new symbol using JKQTPRegisterCustomGraphSymbol(), which is drawn by
    //    a differently parametrized (f1,f2) functor pieFunc.
    const int Ndata=5;
    for (int i=0; i<Ndata; i++) {
        // put data
        const double x=double(i)/double(Ndata-1);
        *(colXInserter++)=x;
        *(colYInserter++)=pow(x*1.3, 2.0);
        *(colSInserter++)=JKQTPRegisterCustomGraphSymbol(std::bind(pieFunc, std::placeholders::_1, x*0.4, 0.5-x*0.2));
    }


    // 5. Finally we create a graph in the plot, which displays our datasets:
    JKQTPXYParametrizedScatterGraph* graph1=new JKQTPXYParametrizedScatterGraph(&plot);
    graph1->setXColumn(columnX);
    graph1->setYColumn(columnY);
    graph1->setSymbolSize(25);
    graph1->setDrawLine(true);
    graph1->setLineWidth(4);
    graph1->setDrawLineInForeground(false);
    graph1->setColor(QColor("black"));
    graph1->setTitle(QObject::tr("pie scatter"));
    // the symbol type is stored in columnS, note however how we have to give a
    // custom JKQTPXYParametrizedScatterGraph::symbolColumnFunctor, because the
    // default one maps the values in the column to the range [0...JKQTPMaxSymbolID]
    // in a cycling fashion (using a mod operation), but here we want to use the
    // stored ID directly.
    graph1->setSymbolColumn(columnS);
    graph1->setSymbolColumnFunctor(std::bind([](double /*x*/, double /*y*/, double symbolcolumn)->JKQTPGraphSymbols {
        return static_cast<JKQTPGraphSymbols>(floor(symbolcolumn));
    }, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
    plot.addGraph(graph1);


    // 6. autoscale the plot so the graph is contained
    plot.setXY(-0.2,1.2,-0.4,2.2);

    // show plotter and make it a decent size
    plot.getXAxis()->setShowZeroAxis(false);
    plot.getYAxis()->setShowZeroAxis(false);
    plot.setGrid(false);
    plot.getPlotter()->setKeyPosition(JKQTPKeyInsideTopLeft);
    plot.getPlotter()->setPlotLabel(QObject::tr("Custom Parametrized Scatter Symbols Example"));
    plot.show();
    plot.resize(500/plot.devicePixelRatioF(),400/plot.devicePixelRatioF());


    return app.exec();
}