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Axis Binding

Axis binding retrieves the currently marked value in a column as base for an axis expression. It is used to set up visualizations with axis expressions changing in response to marking in other visualizations.

Overview

In the user interface the axis binding feature is referred to as Column from Marked. It is accessed from the context menu of the axis selectors. To get acquainted with it, run the Data Relationships tool, which is similar to the example described here.
The purpose of the following example is to explain how to set up axis binding via the API.

Example

The sample uses two data tables. One holds sales data, and starts as follows:

Year	Month	Category	Type	Sales	Cost
2004	January	Fruit	Apples	17	14
2004	January	Fruit	Pears	26	17
2004	January	Fruit	Bananas	31	28
2004	January	Vegetables	Cucumber	13	9
2004	January	Vegetables	Tomatoes	18	14
2004	January	Vegetables	Lettuce	28	26
2004	February	Fruit	Apples	17	12
2004	February	Fruit	Pears	27	18
2004	February	Fruit	Bananas	35	29
2004	February	Vegetables	Cucumber	13	9
2004	February	Vegetables	Tomatoes	15	15
2004	February	Vegetables	Lettuce	26	26
2004	March	Fruit	Apples	14	13
2004	March	Fruit	Pears	24	17
2004	March	Fruit	Bananas	36	29
2004	March	Vegetables	Cucumber	12	10

The columns of the second table contains the names of columns in the first table:

Configuration	X	Y
Category vs. Sales	Category	Sales
Category vs. Cost	Category	Cost
Type vs. Sales	Type	Sales
Type vs. Cost	Type	Cost

Goal

The goal is to create a table visualization that controls the axis in a bar chart:

• The table visualization shows the second data table.
• When the user marks a row in the table, the bar chart is configured by the values in the X and Y columns.

When the user selects the row Category vs. Cost, the bar chart is configured to show the sum of Cost for each category. In the user interface it will look like this:

Code Example

The goal is accomplished by a single method. It is assumed that the first table has been opened and is the default data table. The hypothetical AddConfigurationDataTable method is used to load the second table.

public void CreateTableAndBarChartWithAxisBinding(AnalysisApplication application)
{
    // Add the data table used for defining axis bindings.
    DataTable configurationTable = AddConfigurationDataTable();

    // Create a table visualization
    TablePlot tablePlot = 
        application.Document.ActivePageReference.Visuals.AddNew<TablePlot>();
    tablePlot.Title = "Configurations";

    // Connect the table to data
    tablePlot.Data.DataTableReference = configurationTable;

    // Set filtering for the visualization
    tablePlot.Data.UseActiveFiltering = true;

    // Set marking for the visualization
    DataManager dataManager = application.Document.Data;
    DataMarkingSelection marking = 
        dataManager.Markings.DefaultMarkingReference;
    tablePlot.Data.MarkingReference = marking;

    // Add columns to the table
    tablePlot.Columns.AddRange(new string[]
    {
        "Configuration",
        "X",
        "Y"
    });

    // Create a bar chart whose X and Y axes will be contolled by the marking
    // in the table.
    BarChart barChart = 
        application.Document.ActivePageReference.Visuals.AddNew<BarChart>();
    barChart.Data.DataTableReference =
        dataManager.Tables.DefaultTableReference;
            
    // Setup the x axis to show the column defined by
    // the values in column X.
    AxisBinding xBinding = new AxisBinding();
    xBinding.ColumnReference = configurationTable.Columns["X"];
    xBinding.ExpressionTemplate = "<{0}>";
    xBinding.MarkingReference = marking; 
    barChart.XAxis.Binding = xBinding;

    // Setup the y axis to show the column defined by
    // the values in column Y.
    AxisBinding yBinding = new AxisBinding();
    yBinding.ColumnReference = configurationTable.Columns["Y"];
    yBinding.ExpressionTemplate = "Sum({0})";
    yBinding.MarkingReference = marking;
    barChart.YAxis.Binding = yBinding;
}