Chapter Contents |
Previous |
Next |
The GREDUCE Procedure |
About the Input Map Data Set |
The input map data set must be a map data set and contain these variables:
It also can contain
Any other variables in the input map data set do not affect the GREDUCE procedure.
About Unmatched Area Boundaries |
For example, if the map data set APPROX has horizontal and vertical coordinate values for interior boundaries of unit areas that are exactly equal only to three decimal places, then this DATA step creates a new map data set, EXACT, that will be better suited for use with PROC GREDUCE:
data exact; set approx; if x ne . then x=round(x,.001); if y ne . then y=round(y,.001); run;
See About Map Data Sets for additional information on map data sets.
Chapter Contents |
Previous |
Next |
Top of Page |
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.