ChartDirector 6.0 (C++ Edition)

Stacked Rose Chart




This example demonstrates how to create a stacked rose chart.

This example employs the same approach as the previous Simple Rose Chart example. It creates a PolarChart object as the graph paper, and adding sector zones on it using AngularAxis.addZone. A transparent line layer is used for enabling auto-scaling.

In this example, multiple sectors are added for each angular direction, creating a "stacked" effect.

Source Code Listing

[The following code is available in "cppdemo/stackrose". 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};

    double angles[] = {0, 45, 90, 135, 180, 225, 270, 315};
    const char *labels[] = {"North", "North\nEast", "East", "South\nEast", "South", "South\nWest",
        "West", "North\nWest"};

    // Create a PolarChart object of size 460 x 500 pixels, with a grey (e0e0e0) background and a 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 white
    // text on deep blue background.
    c->addTitle("Wind Direction", "arialbi.ttf", 15, 0xffffff)->setBackground(0x000080);

    LegendBox *legendBox = c->addLegend(230, 35, false, "arialbd.ttf", 9);
    legendBox->setAlignment(Chart::TopCenter);
    legendBox->setBackground(Chart::Transparent, Chart::Transparent, 1);

    legendBox->addKey("5 m/s or above", 0xff3333);
    legendBox->addKey("1 - 5 m/s", 0x33ff33);
    legendBox->addKey("less than 1 m/s", 0x3333ff);

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

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

    // Set angular axis as 0 - 360, with a spoke every 30 units
    c->angularAxis()->setLinearScale(0, 360, StringArray(labels, (int)(sizeof(labels) / sizeof(
        labels[0]))));

    for(int i = 0; i < (int)(sizeof(angles) / sizeof(angles[0])); ++i) {
        c->angularAxis()->addZone(angles[i] - 10, angles[i] + 10, 0, data0[i], 0x3333ff, 0);
        c->angularAxis()->addZone(angles[i] - 10, angles[i] + 10, data0[i], data1[i], 0x33ff33, 0);
        c->angularAxis()->addZone(angles[i] - 10, angles[i] + 10, data1[i], data2[i], 0xff3333, 0);
    }

    // Add an Transparent invisible layer to ensure the axis is auto-scaled using the data
    c->addLineLayer(DoubleArray(data2, (int)(sizeof(data2) / sizeof(data2[0]))), Chart::Transparent)
        ;

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

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