JKQtPlotter/test/jkqtplotter_simpletest_imageplot/jkqtplotter_simpletest_imageplot.cpp

#include <QApplication>
#include <cmath>
#include "jkqtplotter/jkqtplotter.h"
#include "jkqtplotter/jkqtpimageelements.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif


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

    JKQtPlotter plot;
    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
    plot.get_plotter()->set_useAntiAliasingForGraphs(true); // nicer (but slower) plotting
    plot.get_plotter()->set_useAntiAliasingForSystem(true); // nicer (but slower) plotting
    plot.get_plotter()->set_useAntiAliasingForText(true); // nicer (but slower) text rendering
    JKQTPdatastore* ds=plot.getDatastore();

    // 2. now we create data for the charts (taken from https://commons.wikimedia.org/wiki/File:Energiemix_Deutschland.svg)
    const int NX=100; // image dimension in x-direction [pixels]
    const int NY=100; // image dimension in x-direction [pixels]
    const double dx=1e-2; // size of a pixel in x-direction [micrometers]
    const double dy=1e-2; // size of a pixel in x-direction [micrometers]
    const double w=static_cast<double>(NX)*dx;
    const double h=static_cast<double>(NY)*dy;
    double airydisk[NX*NY]; // row-major image

    // 2.1 Parameters for airy disk plot (see https://en.wikipedia.org/wiki/Airy_disk)
    double NA=1.1; // numerical aperture of lens
    double wavelength=488e-3; // wavelength of the light [micrometers]

    // 2.2 calculate image of airy disk in a row-major array
    double x, y=-h/2.0;
    for (int iy=0; iy<NY; iy++ ) {
        x=-w/2.0;
        for (int ix=0; ix<NX; ix++ ) {
            const double r=sqrt(x*x+y*y);
            const double v=2.0*M_PI*NA*r/wavelength;
            airydisk[iy*NX+ix] = pow(2.0*j1(v)/v, 2);
            x+=dx;
        }
        y+=dy;
    }



    // 3. make data available to JKQtPlotter by adding it to the internal datastore.
    //    Note: In this step the data is copied (of not specified otherwise)
    //    the variables cYear, cOther ... will contain the internal column ID of the
    //    newly created columns with names "year" and "other" ... and the (copied) data
    size_t cAiryDisk=ds->addCopiedImageAsColumn(airydisk, NX, NY, "imagedata");

    // 4. create graphs in the plot, which plots the dataset year/other, year/coal, ...
    //    The color of the graphs is set by calling set_fillColor_and_darkenedColor(), which sets the
    //    fillColor to the given color and makes the outline of the bars (i.e. their "color") a darker
    //    shade of the given color.
    JKQTPColumnMathImage* graph=new JKQTPColumnMathImage(&plot);
    graph->set_title("");
    graph->set_imageColumn(cAiryDisk);
    graph->set_Nx(NX);
    graph->set_Ny(NY);
    graph->set_x(-w/2.0);
    graph->set_y(-h/2.0);
    graph->set_width(w);
    graph->set_height(h);
    graph->set_palette(JKQTPMathImageMATLAB); // color-map is "MATLAB"
    graph->get_colorBarRightAxis()->set_axisLabel("light intensity [A.U.]"); // get coordinate axis of color-bar and set its label

    // 5. add the graphs to the plot, so it is actually displayed
    plot.addGraph(graph);

    // 6. set axis labels
    plot.get_xAxis()->set_axisLabel("x [{\\mu}m]");
    plot.get_yAxis()->set_axisLabel("y [{\\mu}m]");

    // 7. fix axis and plot aspect ratio to 1
    plot.get_plotter()->set_maintainAspectRatio(true);
    plot.get_plotter()->set_maintainAxisAspectRatio(true);

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

    // show plotter and make it a decent size
    plot.show();
    plot.resize(600,600);
    plot.setWindowTitle("JKQTPColumnMathImage");


    return app.exec();
}