Mapping Data to a Template

To replace the data source for a template stream with a new source node bringing your own data into IBM® SPSS® Modeler, you should use the Select Replacement Node option from the Data Mapping pop-up menu. This option is available for all nodes except Merge, Aggregate, and all terminal nodes. Using the data mapping tool to perform this action helps ensure that fields are matched properly between the existing stream operations and the new data source. The following steps provide an overview of the data mapping process.

Step 1: Specify essential fields in the original source node. In order for stream operations to run properly, essential fields should be specified. See the topic Specifying Essential Fields for more information.

Step 2: Add new data source to the stream canvas. Using one of the source nodes, bring in the new replacement data.

Step 3: Replace the template source node. Using the Data Mapping option on the pop-up menu for the template source node, click Select Replacement Node, then select the source node for the replacement data.

Step 4: Check mapped fields. In the dialog box that opens, check that the software is mapping fields properly from the replacement data source to the stream. Any unmapped essential fields are displayed in red. These fields are used in stream operations and must be replaced with a similar field in the new data source in order for downstream operations to function properly. See the topic Examining Mapped Fields for more information.

After using the dialog box to ensure that all essential fields are properly mapped, the old data source is disconnected and the new data source is connected to the stream using a Filter node called Map. This Filter node directs the actual mapping of fields in the stream. An Unmap Filter node is also included on the stream canvas. The Unmap Filter node can be used to reverse field name mapping by adding it to the stream. It will undo the mapped fields, but note that you will have to edit any downstream terminal nodes to reselect the fields and overlays.