Pitney Bowes MapInfo Professional - Manual (Page 435)

The STATES table used in this example is from the MapInfo Professional Tutorial data, which
is available from the Pitney Bowes Software Inc. web site,
http://go.pbinsight.com/webtutorials .
Note:
But that is only one part of the redistricting process. The real power lies in the Districts Browser where
you can see on-the-fly updates of district record counts and data totals when you click a map object and
assign it to another district. This allows you to perform visual "what if" analysis to achieve district
realignments, a process sometimes referred to as load balancing.
When you are satisfied with the distribution, you can make the district assignments permanent. Later,
as the need arises, you can change the assignments and try out new distributions.
Redistricting does not create new map objects or permanently change the style of the map objects.
Redistricting is simply a dynamic grouping tool that displays map objects that share the same district
information as a group. While the map objects are not permanently affected, you can make the district
assignments permanent by saving the table.
You can redistrict any mappable table containing region, line, or point objects. The redistrict map will
reflect the appropriate fill, line, or symbol style for the objects. The Redistricter limits the number of
districts in a table to 594.
You can use redistricting in a wide variety of applications such as creating and managing sales territories,
school or voter districts, emergency service coverage areas, delivery routes, natural resource management
areas, etc. Use it wherever there is a high degree of fluctuating data and the need to try out different
realignment scenarios.
You can use redistricting whether you need to create districts from scratch or realign existing districts.
Before we get into the process, however, there are two key concepts to introduce: the Districts Browser
and Target District.
Using the Districts Browser
The Districts Browser is the key to the process of creating and changing districts. While looking like other
Browsers in MapInfo Professional, the Districts Browser is actually a dynamic window that allows you
to make changes to the groups and recalculates total values on the fly. You can immediately see the
results of your changes. You then have the option to make the changes permanent or continue to try
out new district realignments.
The Browser window lists the districts as specified in your table, the record count for each district, and
aggregate expression columns that contain the net total values of your data. You specify these columns
in the New Redistrict Window dialog box when you begin the redistricting session.
435 MapInfo Professional User Guide
Chapter 17: Specialized Topics in MapInfo Professional