ChartDirector 6.0 (C++ Edition)

Bubble XY Scaling




This example demonstrates a bubble chart with independent x and y bubble sizes and non-circular bubbles.

In ChartDirector, a bubble chart in general is a scatter layer with the symbol sizes controlled by some other data series.

ChartDirector supports using arbitrary symbols as bubbles. Thus bubble shape is not limited to circle but can be any shapes.

Furthermore, ChartDirector supports independent x and y sizes for bubbles. This is useful for creating charts in which the bubbles reflect some features of the data points, such as its confidence zone, x and y errors, x and y standard deviations, etc.

Source Code Listing

[The following code is available in "cppdemo/bubblescale". 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[])
{
    // The XY points for the bubble chart. The bubble chart has independent bubble size on the X and
    // Y direction.
    double dataX0[] = {1000, 1500, 1700};
    double dataY0[] = {25, 20, 65};
    double dataZX0[] = {500, 200, 600};
    double dataZY0[] = {15, 30, 20};

    double dataX1[] = {500, 1000, 1300};
    double dataY1[] = {35, 50, 75};
    double dataZX1[] = {800, 300, 500};
    double dataZY1[] = {8, 27, 25};

    double dataX2[] = {150, 300};
    double dataY2[] = {20, 60};
    double dataZX2[] = {160, 400};
    double dataZY2[] = {30, 20};

    // Create a XYChart object of size 450 x 420 pixels
    XYChart *c = new XYChart(450, 420);

    // Set the plotarea at (55, 65) and of size 350 x 300 pixels, with a light grey border
    // (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0)
    c->setPlotArea(55, 65, 350, 300, -1, -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, "timesbi.ttf", 12)->setBackground(Chart::Transparent);

    // Add a title to the chart using 18pt Times Bold Itatic font.
    c->addTitle("Plasma Battery Comparison", "timesbi.ttf", 18);

    // Add titles to the axes using 12pt Arial Bold Italic font
    c->yAxis()->setTitle("Operating Current", "arialbi.ttf", 12);
    c->xAxis()->setTitle("Operating Voltage", "arialbi.ttf", 12);

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

    // Add (dataX0, dataY0) as a standard scatter layer, and also as a "bubble" scatter layer, using
    // circles as symbols. The "bubble" scatter layer has symbol size modulated by (dataZX0,
    // dataZY0) using the scale on the x and y axes.
    c->addScatterLayer(DoubleArray(dataX0, (int)(sizeof(dataX0) / sizeof(dataX0[0]))), DoubleArray(
        dataY0, (int)(sizeof(dataY0) / sizeof(dataY0[0]))), "Vendor A", Chart::CircleSymbol, 9,
        0xff3333, 0xff3333);
    c->addScatterLayer(DoubleArray(dataX0, (int)(sizeof(dataX0) / sizeof(dataX0[0]))), DoubleArray(
        dataY0, (int)(sizeof(dataY0) / sizeof(dataY0[0]))), "", Chart::CircleSymbol, 9, 0x80ff3333,
        0x80ff3333)->setSymbolScale(DoubleArray(dataZX0, (int)(sizeof(dataZX0) / sizeof(dataZX0[0]))
        ), Chart::XAxisScale, DoubleArray(dataZY0, (int)(sizeof(dataZY0) / sizeof(dataZY0[0]))),
        Chart::YAxisScale);

    // Add (dataX1, dataY1) as a standard scatter layer, and also as a "bubble" scatter layer, using
    // squares as symbols. The "bubble" scatter layer has symbol size modulated by (dataZX1,
    // dataZY1) using the scale on the x and y axes.
    c->addScatterLayer(DoubleArray(dataX1, (int)(sizeof(dataX1) / sizeof(dataX1[0]))), DoubleArray(
        dataY1, (int)(sizeof(dataY1) / sizeof(dataY1[0]))), "Vendor B", Chart::SquareSymbol, 7,
        0x3333ff, 0x3333ff);
    c->addScatterLayer(DoubleArray(dataX1, (int)(sizeof(dataX1) / sizeof(dataX1[0]))), DoubleArray(
        dataY1, (int)(sizeof(dataY1) / sizeof(dataY1[0]))), "", Chart::SquareSymbol, 9, 0x803333ff,
        0x803333ff)->setSymbolScale(DoubleArray(dataZX1, (int)(sizeof(dataZX1) / sizeof(dataZX1[0]))
        ), Chart::XAxisScale, DoubleArray(dataZY1, (int)(sizeof(dataZY1) / sizeof(dataZY1[0]))),
        Chart::YAxisScale);

    // Add (dataX2, dataY2) as a standard scatter layer, and also as a "bubble" scatter layer, using
    // diamonds as symbols. The "bubble" scatter layer has symbol size modulated by (dataZX2,
    // dataZY2) using the scale on the x and y axes.
    c->addScatterLayer(DoubleArray(dataX2, (int)(sizeof(dataX2) / sizeof(dataX2[0]))), DoubleArray(
        dataY2, (int)(sizeof(dataY2) / sizeof(dataY2[0]))), "Vendor C", Chart::DiamondSymbol, 9,
        0x00ff00, 0x00ff00);
    c->addScatterLayer(DoubleArray(dataX2, (int)(sizeof(dataX2) / sizeof(dataX2[0]))), DoubleArray(
        dataY2, (int)(sizeof(dataY2) / sizeof(dataY2[0]))), "", Chart::DiamondSymbol, 9, 0x8033ff33,
        0x8033ff33)->setSymbolScale(DoubleArray(dataZX2, (int)(sizeof(dataZX2) / sizeof(dataZX2[0]))
        ), Chart::XAxisScale, DoubleArray(dataZY2, (int)(sizeof(dataZY2) / sizeof(dataZY2[0]))),
        Chart::YAxisScale);

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

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