ChartDirector 6.0 (C++ Edition)

Polar Area Chart




This examples demonstrates a polar area chart.

The polar area layer is created using PolarChart.addAreaLayer. In this example, 3 area layers are used. The area data are already stacked before passing to ChartDirector.

Source Code Listing

[The following code is available in "cppdemo/polararea". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
#include "chartdir.h"

int main(int argc, char *argv[])
{
    // Data for the chart
    double data0[] = {5, 3, 10, 4, 3, 5, 2, 5};
    double data1[] = {12, 6, 17, 6, 7, 9, 4, 7};
    double data2[] = {17, 7, 22, 7, 18, 13, 5, 11};

    const char *labels[] = {"North", "North<*br*>East", "East", "South<*br*>East", "South",
        "South<*br*>West", "West", "North<*br*>West"};

    // Create a PolarChart object of size 460 x 500 pixels, with a grey (e0e0e0) background and 1
    // pixel 3D border
    PolarChart *c = new PolarChart(460, 500, 0xe0e0e0, 0x000000, 1);

    // Add a title to the chart at the top left corner using 15pt Arial Bold Italic font. Use a wood
    // pattern as the title background.
    c->addTitle("Polar Area Chart Demo", "arialbi.ttf", 15)->setBackground(c->patternColor(
        "wood.png"));

    // Set center of plot area at (230, 280) with radius 180 pixels, and white (ffffff) background.
    c->setPlotArea(230, 280, 180, 0xffffff);

    // Set the grid style to circular grid
    c->setGridStyle(false);

    // Add a legend box at top-center of plot area (230, 35) using horizontal layout. Use 10pt Arial
    // Bold font, with 1 pixel 3D border effect.
    LegendBox *b = c->addLegend(230, 35, false, "arialbd.ttf", 9);
    b->setAlignment(Chart::TopCenter);
    b->setBackground(Chart::Transparent, Chart::Transparent, 1);

    // Set angular axis using the given labels
    c->angularAxis()->setLabels(StringArray(labels, (int)(sizeof(labels) / sizeof(labels[0]))));

    // Specify the label format for the radial axis
    c->radialAxis()->setLabelFormat("{value}%");

    // Set radial axis label background to semi-transparent grey (40cccccc)
    c->radialAxis()->setLabelStyle()->setBackground(0x40cccccc, 0);

    // Add the data as area layers
    c->addAreaLayer(DoubleArray(data2, (int)(sizeof(data2) / sizeof(data2[0]))), -1,
        "5 m/s or above");
    c->addAreaLayer(DoubleArray(data1, (int)(sizeof(data1) / sizeof(data1[0]))), -1, "1 - 5 m/s");
    c->addAreaLayer(DoubleArray(data0, (int)(sizeof(data0) / sizeof(data0[0]))), -1,
        "less than 1 m/s");

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

    //free up resources
    delete c;
    return 0;
}