Working with Roles :: SAS(R) Visual Analytics 6.3: User's Guide

About Roles

When you create a custom graph object, you determine which data roles become available for assignment. However, you do not assign data to those roles in the graph builder. When the graph object becomes available to report designers for use in their reports, the report designers assign data items to the available roles.

Here are the tasks that you can perform related to roles:

Provide meaningful names for the roles. For more information, see About Role Names.
Create additional roles. For more information, see Create Optional Roles.
Share roles across two or more graph elements. For more information, see Share Data Roles.
Specify a role for a data-driven lattice. For more information, see Creating a Data-Driven Lattice .

About Role Names

When you drag and drop a graph element onto the canvas, the required roles for that graph element are created with default names on the Role Definitions tab. You can specify different names for the roles by changing the default names.

When you specify the name for a role definition, specify a name that helps report designers understand which type of data to assign. Therefore, role names should be meaningful to report designers. Example names are Category, Response, Time, X variable, Y variable, Numeric X variable, Numeric Y variable, and so on. Normally, you do not specify names that reflect the particular data, such as sales items, unless you know that the graph object will be used only with that particular data.

Create Optional Roles

When you drag and drop a graph element onto the canvas, the required roles for that graph element are created on the Role Definitions tab. You can create additional, optional roles.

To create an optional role:

On the Role Definitions tab, click Add Role. The Add Role window is displayed. The contents of the Add Role window vary depending on the current graph element.
Select the type of role that you want to create. For more information, see Types of Roles.
(Optional) You can change the default role name to provide a more meaningful name. For more information, see About Role Names.
Select the data type for the role. For information about the data types, see Working with Data Items in a Report.
(Optional) Select Required to require report designers to assign data to the role. If this option is not selected, then report designers can choose whether to assign data to the role.
If the Allow multiple data assignments check box is available, then you can select or clear the check box. When this option is selected, the role can have more than one measure assigned. For example, in a line chart, if multiple measures are assigned to the Y axis, then the graph shows a line for each measure.
Click OK.

Types of Roles

In addition to the standard roles, such as Time, X, or Category, you can add the following roles by clicking Add Role on the Role Definitions tab. The roles that are available depend on the type of graph element.

The Group role specifies a data column that is used to group the data. The graph elements for each unique group value are automatically distinguished by different visual attributes, such as color, line style, and so on. The Group role can be a Category or a Datetime data type.
The Color role specifies a data column that is used to color the data.

The following example shows the heights of a group of students. A student’s gender is specified for the Color role.

The Color role can be any data type. In this example, the Color role is assigned a Category data type.

Note: When you add the Color role to a graph element in a data-driven lattice, the Measure data type is not always available. The Measure data type is not available for a bar chart, a waterfall chart, or a scatter plot.

In some graph elements, such as a bar chart, the Group role also colors the graph based on the values of the group variable. In those graph elements, the Color role is used to color the data across a color gradient as shown in the following example. In this case, the Color role must be a Measure data type.

In this example, the color gradient indicates the age range of the students.
The Data Tip role specifies a data column that is used for data tips. The Data Tip role must be numeric.