Combining layers

A combined vector layer amalgamates several vector layers into one. For example, one vector layer covering the eastern U.S.A. can be combined with another layer covering the western U.S.A. to produce a virtual single layer for the entire country. When you combine layers, the data is linked, not duplicated. The combined layer does not store data; rather, it serves as a pointer to the source data.

You can combine vector layers from your current data files and from other source files with a two-part process to locate and select the data you want to combine.

To combine layers

Make sure you have at least two PCIDSK files open in the control pane.
On the Files tab, right-click the file for which you want to combine layers, point to New, and then click Combined Vector Layer.
The Combined Layer window appears.
Click Browse, and then in the Select Layer window, in the File list, select the file you want.
In the Layers available box, select the layer you want, and then click OK.
The layers and common columns are listed in the Combined Layer window. In the Layer list box, two or more entries that you can combine are listed. In the Common attributes list box, you need not make any selection; that is, the box merely lists the the columns (fields/attributes) that are present in each layer.
Click OK.
A new layer is added to the Files tab. In the view pane, you can view the new layer and combined data. To see all the combined shapes, on the Layer menu, click Attribute Manager. Layers common to both input layers are listed twice.