Custom boundaries are boundaries you create. These boundaries can be drawn using the mouse or they can be based on existing boundaries, such as groups of counties or states. One common example is basing sales territories on county boundaries. MapViewer allows you to create your own boundaries based on groupings of county boundaries (or any types of boundaries), and then you can create a map showing those sales territories.
There are different ways you can create custom boundaries. You can:
Select existing boundaries that define your new boundary, and use the Combine Islands/Lakes command to group them into a single complex boundary. You can then assign custom fill properties, line properties, a primary ID, additional IDs, and a hyperlink. See Selecting Objects for more information on selecting several objects at one time.
Use the mouse to trace around the outside of the boundaries (see the Tracing an Existing Boundary section of the Area command). This method is effective if your boundaries parallel existing boundaries in some places, but cut across boundaries in others. For example, if your boundary is made up of only one-half of a county boundary, you can trace along the county where it and your boundary are coincident, and freehand draw where your boundary does not follow any existing boundary lines.
Use the commands under Boundary | New Boundaries to create new objects.
Draw boundaries freehand using the Polygon, Spline Polygon, Polyline, Spline Polyline, or Point commands. You can also use the Ellipse, Rectangle, and Rounded Rectangle commands and then convert the shapes into boundary objects with the Symmetric Shape to Area command.
Use the Digitize command to digitize in the XY coordinates, and save the file as an Atlas BNA file. This is an advanced procedure, and requires familiarity with digitizing and creating Atlas BNA files. The Boundary | Digitize command is useful for small digitizing projects. If you have a large, complex project it is better to use software specifically created for digitizing, such as Golden Software's Didger.
After you create custom boundaries, you can use them in a thematic map if you have assigned primary IDs to your boundaries and have created a data file that also contains the primary IDs.
You can export your custom boundaries to a boundary file using the Export command.
See Also
Linking Data to Boundaries - The Primary ID