Pitney Bowes MapInfo Professional - Manual (Page 301)

The Area Proportion radio button is active if the selected field is numeric. Also the Value entry field is
enabled when you select the Value radio button and the drop-down list contains "none".
Splitting Objects
Splitting Objects allows you to divide the target object into smaller objects, using another object as a
cutter. You can also combine objects into territories using redistricting. For more about the redistricting
process, see
Redistricting-Grouping Map Objects into Districts in the MapInfo Professional Help
System. For example, you might use Split to separate a large territory into smaller units.
You can split either closed objects (regions, ellipses, rectangles, or rounded rectangles) or open objects
(polylines, lines and arcs) using the Split command. You cannot use Split on points or text objects or to
cut objects that are not in editable layers.
• For specific instructions, see Splitting Objects in the Help System.
Proportioning Associated Data after Using Split
After using Objects > Split, you may want to proportion (disaggregate) the associated data. Data
disaggregation splits the data associated with a map object into smaller parts to match the new map
objects. For instance, you may want to split a state into regions and have the data previously associated
with the entire state proportioned for each new region. When you initiate the Split command, a Data
Disaggregation dialog box appears that allows you to specify how the data will be proportioned.
Splitting Map Objects Using a Polyline
You can split multipoints and collections, as well as closed objects (regions, ellipses, rectangles, and
rounded rectangles), and linear objects (polylines, lines and arcs) using the Polyline Split command.
As mentioned previously, splitting objects requires that the cutter be a closed object. With Split Using
Polyline, the polyline cutter will first be transformed into a region suitable for the cutter operation. The
region created will be displayed for acceptance. The polyline(s) used as the cutter must be contiguous
and non-branching. In general, if the cutter polylines were to be combined, the result would be a one
single section polyline. If the cutters are not polylines, and are not contiguous and non-branching, then
an error will occur, and the operation will be cancelled.
You cannot use Polyline Split on text objects or to cut objects that are not in editable layers. Note:
• For specific instructions, see Splitting MapObjects Using a Polyline in the Help System.
Creating Territories by Combining Objects
Creating territories is one of the most common tasks performed with MapInfo Professional. Most people
create territories by combining two or more smaller regions to create a larger one. Police departments
combine postal code boundaries to create precinct boundaries. Sales managers combine county
boundaries or state boundaries to create sales territories. Political analysts combine census tract
boundaries to create voting districts.
Remember, when you are combining regions, you are also combining the data associated with the
regions. If you combine regions without somehow aggregating the data associated with the regions, that
data will be lost. For some applications, you might not want to save your data. For example, you are
merging census tract boundaries to create school districts. The census tract data is of no interest to you;
you merely want the boundaries. There is no reason to aggregate the data, but you would want to
apportion the demographic data. For most tasks, you'll want to save the data associated with the regions.
MapInfo Professional gives you three methods for combining regions.
1. The first method, Combine, works with objects that are selected.
301 MapInfo Professional User Guide
Chapter 11: Buffering and Working with Objects