The Boundary | Edit
Boundaries | Thin command 
removes vertices from a selected polyline
or polygon. Thinning is accomplished using one of three
methods: Deviation distance,
Keep every nth vertex, or Vertex averaging. To thin an area,
specifying the Thinning method
and the rate or distance to remove points. MapViewer
uses these options to determine a series of straight-line segments that
approximate the area or curve. The Thin
Boundary command can be used on one or more objects at the same
time.
Thinning boundaries reduces their complexity.
The boundary on the right has been thinned.
The Thin Boundary dialog contains options for the
thinning method and for the distance or rate of
vertex removal.
The total number of points in the selected objects is displayed in the Current points in selection field.
The Deviation distance thinning method controls how many points are removed by the thinning process. Points closer than the Deviation distance from the general trend of the line are removed. A distance of 0 does not remove any points. A distance of 0.1 inch removes all points that are 0.1 inch or closer to the general trend of the line. The deviation distance must be between 0 and 10.00 inches.
The Keep every nth vertex thinning method keeps every nth vertex point from the curve or area, and then reconnects the line segments. For example, if the Removal rate is set to 10, the first node is kept, the next nine vertices are removed, the tenth is kept, and so on.
Vertex averaging preserves the first and last point in a curve or area, but averages the vertices along the object based on the number set in the Average rate field. For example, a curve that has 10 vertices when averaged using an Average rate of three yields a curve with six vertices.
The Preview button allows you to see what the selected objects look like after thinning. Different thinning methods may be quickly tried out by entering the distance or rate value and clicking Preview to view the results. To return to the original number of vertices, enter 0 as the Deviation distance or 1 as the Removal rate or Average rate. You can also click the Cancel button to return to the original number of vertices.
See Also