Pitney Bowes MapInfo Vertical Mapper - Manual (Page 171)

Chapter 9: Data Analysis
User Guide
169
Some polygons may be too small for a grid node to be located inside. In this instance
the polygons data is attributed to the closest node. This would be the node to the
upper right of the selected region in the above diagram.
This problem can be minimized by decreasing the cell size used in the analysis. You can determine
what is a reasonable cell size by clicking the Advise button in the Polygon Overlay dialog box. The
polygon file is analyzed automatically to determine how many regions will not have a grid cell
located within their boundaries. Note that if you decrease the cell size, longer processing time and
more temporary space on your computer system are required. You may also run into situations
where there are a certain number of problem polygons, even when the cell size is dramatically
decreased. This is symptomatic of sliver polygons in the data set that should be deleted from the file.
After selecting what you think is a reasonable cell size, you can run the analysis using the Create
Problem Table option. This will generate a region file of all polygons in the table that do not have a
node located inside. If necessary, you can adjust the cell size to reduce the number of problem
regions.
Exploring the Polygon Overlay Dialog Box
The Table to Update list box enables you to choose the target table that will be updated with the
source data.