Bubble Chart

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Short Description

The Bubble Chart is represented by the BubbleSeriesView object, which belongs to Point Series Views. This view, in addition to other point diagram capabilities, allows you to visually represent data that has a third dimension (it is the BubbleLabelValueToDisplay.Weight of a series point), expressed in a bubble's size. You map two dimensions along the usual X and Y axes, and then the third dimension is displayed as a shape (a filled circle - "bubble", or a star, triangle, etc.) at the data point. Also, you can specify the size of the smallest and largest marker for the chart, by using the BubbleSeriesView.MaxSize and BubbleSeriesView.MinSize properties of the series view.

An example of the Bubble chart is shown in the image below. Note that this chart type is based upon the XYDiagram, so it can be rotated to change axis positions.

SeriesView_Bubble

Chart Type Characteristics

The table below lists the main characteristics of this chart type.

Feature Value
Series View type BubbleSeriesView
Diagram type 2D-XYDiagram
Number of arguments per series point 1
Number of values per series point 2 (Value and Weight)
NOTE

For information on which chart types can be combined with the Bubble Chart, refer to the Series Views Compatibility document.

Example

The following example demonstrates how to create a ChartControl with two series of the BubbleSeriesView type, and add this chart to a form at runtime. Before proceeding with this example, create a Windows Forms Application in Visual Studio, and add all required assemblies to the References list of your project.

Then, add the following code to the Form.Load event handler.

using System;
using System.Windows.Forms;
using DevExpress.XtraCharts;
// ...

namespace Series_BubbleChart {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {
            // Create a new chart.
            ChartControl bubbleChart = new ChartControl();

            // Create two bubble series.
            Series series1 = new Series("Series 1", ViewType.Bubble);
            Series series2 = new Series("Series 2", ViewType.Bubble);

            // Add points to them.
            series1.Points.Add(new SeriesPoint(1, 11, 2));
            series1.Points.Add(new SeriesPoint(2, 10, 1));
            series1.Points.Add(new SeriesPoint(3, 14, 3));
            series1.Points.Add(new SeriesPoint(4, 17, 2));

            series2.Points.Add(new SeriesPoint(1, 15, 3));
            series2.Points.Add(new SeriesPoint(2, 18, 4));
            series2.Points.Add(new SeriesPoint(3, 25, 2));
            series2.Points.Add(new SeriesPoint(4, 33, 1));

            // Add both series to the chart.
            bubbleChart.Series.AddRange(new Series[] { series1, series2 });

            // Set the numerical argument scale types for the series,
            // as it is qualitative, by default.
            series1.ArgumentScaleType = ScaleType.Numerical;
            series2.ArgumentScaleType = ScaleType.Numerical;

            // Access the view-type-specific options of the series.
            ((BubbleSeriesView)series1.View).AutoSize = false;
            ((BubbleSeriesView)series1.View).MaxSize = 1;
            ((BubbleSeriesView)series1.View).MinSize = 0.3;
            ((BubbleSeriesView)series1.View).BubbleMarkerOptions.Kind = MarkerKind.Circle;

            // Access the type-specific options of the diagram.
            ((XYDiagram)bubbleChart.Diagram).Rotated = true;

            // Hide the legend (if necessary).
            bubbleChart.Legend.Visibility = DevExpress.Utils.DefaultBoolean.False;

            // Add a chart to the form.
            bubbleChart.Dock = DockStyle.Fill;
            this.Controls.Add(bubbleChart);
        }
    }
}
TIP

A complete sample project is available in the DevExpress Code Examples database at http://www.devexpress.com/example=E904.

See Also