%CENTROID Macro
Retrieves the centroids of polygons
| Variables written out: |
X, Y, id variables |
| Requirement: |
You must run the %ANNOMAC macro before using
any other annotate macros. For more information, see Making the Macros Available. |
Syntax
%CENTROID (input-data-set, output-data-set, list-of-id-variables <SEGONLY= n>);
Parameters
- input-data-set
-
specifies a map data
set. The input map data set must be sorted by the ID variables.
- output-data-set
-
contains the ID variables
and the X and Y variables.
- list-of-id-variables
-
specifies the variables
each of which is to be assigned the centroid coordinates of each observation
in the input-data-set. There will be one observation for each unique
set of ID values. If you specify more than one ID variable, then separate
each variable with a space.
- SEGONLY= n
-
specifies that only
the nth segment of each map
area is used to calculate the centroid. For example, if you specify
SEGONLY=1, then only the first segment of each area is used.