Types of spatial relationships that can be validated
In a map display, it is likely that you will find features that spatially relate to each other, whether they are a road on a land feature or a lake surrounded by grassland. It is also possible for features from the same feature class to overlap one another and share attributes. The Geometry on Geometry check searches for features from either the same or two different feature classes that share a spatial relationship.
Spatial relationship types
The types of relationships that can be used with this check include the following:
The check's results are based on the relationship of feature class 1 to feature class 2, as indicated below.
- Touches—A part of the feature from feature class 1 comes into contact with the boundary of a feature from feature class 2. The interiors of the features do not intersect.
- Contains—A feature from feature class 1 completely encloses a feature from feature class 2.
- Intersects—Any part of a feature from feature class 1 comes into contact with any part of a feature from feature class 2.
- Relation—A custom spatial relationship is defined based on the interior, boundary, and exterior of features from both feature classes.
- Within—A feature from feature class 2 completely encloses a feature from feature class 1.
- Crosses—The interior of a feature from feature class 1 comes into contact with the interior or boundary (if a polygon) of a feature from feature class 2 at a point.
- Overlaps—The interior of a feature from feature class 1 partly covers a feature from feature class 2. Only features of the same geometry can be compared.
The combinations of geometry types and the spatial relationships that can be used are listed below:
Feature class 1 |
Feature class 2 |
Compatible spatial relationship types |
---|---|---|
Point |
Point |
|
Point |
Multipoint |
|
Point |
Line |
|
Point |
Area |
|
Multipoint |
Point |
|
Multipoint |
Multipoint |
|
Multipoint |
Line |
|
Multipoint |
Area |
|
Line |
Point |
|
Line |
Multipoint |
|
Line |
Line |
|
Line |
Area |
|
Area |
Point |
|
Area |
Multipoint |
|
Area |
Line |
|
Area |
Area |
|
In addition to spatial analysis, the Compare Attributes dialog box optionally allows attributes between feature classes to be compared. For example, in the Nautical S-57 data model, sounding points that exist within depth area polygons must have depth (z) field values that are within the minimum and maximum depth (z) field values specified in the depth area polygon that contains them. SQL WHERE clauses can be constructed on the Compare Attributes dialog box to perform attribute comparison on the features along with spatial analysis.
Inverse relationships
The Geometry on Geometry check also allows you to find features that do not share the spatial relationship you specify. For example, you can search for lines and polygons that do not intersect each other. However, you can only find inverse relationships using the Contains, Crosses, Intersects, Overlaps, Touches, and Within relationship types. You cannot find these types of relationships using the Relation relationship type.
The Relation spatial relationship
When you choose Relation as the spatial relationship type, you can compare any possible spatial intersections between two shapes based on the following three aspects:
- Interior—The entire shape, except for its boundary. All geometry types have interiors.
- Boundary—The endpoints of all linear parts for line features, or the linear outline of a polygon. Only lines and polygons have boundaries.
- Exterior—The outside area of a shape. All geometry types have exteriors.
This spatial relationship is defined using a 9-character string that is composed of the following characters:
- T (true)—The features have interiors, boundaries, and/or exteriors that intersect.
- F (false)—The features do not have interiors, boundaries, and/or exteriors that intersect.
- 0 (nondimensional)—The intersection between the interiors, boundaries, and/or exteriors of the features forms a point.
- 1 (one dimensional)—The intersection between the interiors, boundaries, and/or exteriors of the features forms a line.
- 2 (two dimensional)—The intersection between the interiors, boundaries, and/or exteriors of the features forms a polygon.
- * (do not check)—An aspect of the relationship between the interiors, boundaries, and/or exteriors is not checked.
The placement of the respective characters is important because it indicates what is going to be checked between the two features. For example, if the first character in the string is T, the Geometry on Geometry check looks at the interiors of features from both feature classes to see if they intersect; or if the first character in the string is 0, the check would return two line features that cross interiors at a point, but not two line features that have any congruent lengths.
The "Not" option cannot be used when the Relation type check is chosen as the spatial relation check.
The order of the characters is as follows:
Character number |
Feature class 1 |
Feature class 2 |
---|---|---|
1 |
Interior |
Interior |
2 |
Interior |
Boundary |
3 |
Interior |
Exterior |
4 |
Boundary |
Interior |
5 |
Boundary |
Boundary |
6 |
Boundary |
Exterior |
7 |
Exterior |
Interior |
8 |
Exterior |
Boundary |
9 |
Exterior |
Exterior |
Specific patterns that can be used to find specific relationships are listed in the table below.
Spatial relationship | Selection geometry | Requested geometry | String |
---|---|---|---|
Contains | Line | Line | TT*FFT*** |
Contains | Point | Line | TT*FFT*** |
Contains | Point | Point | T******** |
Contains | Line | Poly | TT*FFT*** |
Contains | Poly | Poly | TT*FFT*** |
Crosses | Line | Line | TF*FF**** |
Crosses | Poly | Line | TT**F**** |
Crosses | Line | Poly | TT**T**** |
Overlaps | Line | Line | TT*T***** |
Overlaps | Point | Point | T******** |
Overlaps | Poly | Poly | TT*T***** |
Touch | Line | Line | FF*FT**** |
Touch | Poly | Line | FF*FT**** |
Touch | Line | Poly | FF*FT**** |
Touch | Poly | Poly | FF*FT**** |
Within | Line | Line | TF**F**** |
Within | Point | Line | T******** |
Within | Point | Point | T******** |
Within | Line | Poly | TF**F**** |
Within | Poly | Poly | TF**F**** |
Examples of strings that would be used in the Spatial Relationship text box are as follows:
Spatial relationship |
String to use |
---|---|
Shares a boundary. |
****T**** |
Shares a boundary and interiors intersect. |
T***T**** |
Shares a boundary and interiors do not intersect. |
F***T**** |
Does not touch the boundary and interiors intersect. |
T***F**** |
Boundary of a polygon intersects the interior of a line along a congruent length. |
***1***** |