Spatial Match Behavior

The behavior of the Spatial Match tool depends on the intersection method selected (Intersects, Contains or Within) and the types of the objects being tested. The tables below list the various combinations.

Intersects

A Spatial Object...	intersects a...	if...	The type of the returned intersection object (if requested) is...
Polygon	Polygon	the polygons share any area. Touching edges without overlap is not considered an intersect.	Polygon
Polygon	Line	the line touches the edge or interior of the polygon	Polyline
Polygon	Point	the polygon contains the point	Point
Line	Line	any part of the lines cross each other or share endpoints	Point Lines may intersect at multiple points, in which case 1 point is returned and a warning is issued.
Line	Point	the point is a vertex of the line. Note: A line may cross over a point geometrically without a vertex there, and this is not counted as an intersection.	Point
MultiPoint	any object	if it intersects any of the points	MultiPoint
Point	Point	the points are the same	Point

Contains & Within

A TARGET...	Contains a UNIVERSE...	if...
Polygon	Polygon	99.99% of the second polygons area lies inside the first polygon.
Polygon	Line	99.99% of the length of the line lies inside the polygon.
Polygon	Point	the point is inside the polygon
Polygon	MultiPoint	all the points are in the polygon.
Line	Polygon	Never.
Line	Line	Every segment (i.e. 2-point series) in the contained line also appears in the containing line. Segments consisting of the same 2 points in the opposite order (i.e. coded in the opposite direction) will still match. Lines that follow the same route geometrically may still not match if one uses more (unnecessary) points.
Line	Point	the point is a vertex of the line. A line may cross over a point geometrically without a vertex, and the line will not be counted as containing the point.
Line	MultiPoint	all the points are vertexes of the line.
MultiPoint	MultiPoint	all the universe points are in the target.
MultiPoint	Point	one of the points are in the MultiPoint.
MultiPoint	Polygon or Line	Never.
Point	Polygon	Never.
Point	Line	Never.
Point	Point	The points are the same.

Spatial index

If specifying a Calgary (cydb) file, be aware that the Calgary spatial index uses 5 decimal places of accuracy for compression and speed. The YXDB spatial index uses 6 decimal places. This adds an addition round off error of up to a maximum of 1.8 feet to Calgary indexes. In other words, it is possible that a point can be 1.8 feet inside of a polygon and be found as outside in Calgary.