﻿ Relate Method (GeometryEngine)—ArcGIS Pro
ArcGIS Pro 3.2 API Reference Guide
ArcGIS.Core.Geometry Namespace / GeometryEngine Class / Relate Method
The first geometry in the relation.
The second geometry in the relation.
The DE-9IM matrix relation encoded as a string.
Example

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Relate Method (GeometryEngine)
In This Topic
Performs custom relational operations between two geometries using a Dimensionally Extended Nine-Intersection Model, DE-9IM, formatted string.
Syntax
```public bool Relate(
Geometry geometry1,
Geometry geometry2,
string relateString
)```
```Public Function Relate( _
ByVal geometry1 As Geometry, _
ByVal geometry2 As Geometry, _
ByVal relateString As String _
) As Boolean```

#### Parameters

geometry1
The first geometry in the relation.
geometry2
The second geometry in the relation.
relateString
The DE-9IM matrix relation encoded as a string.

#### Return Value

Returns true if the relation holds, false otherwise.
Exceptions
ExceptionDescription
Either geometry1 or geometry2 or both are null.
The method is not implemented for GeometryBag or Multipatch.
Incompatible spatial references between the input geometries.
Invalid relate string; the string is null.
Spatial reference of geometry1or geometry2is an image coordinate system.
Remarks
The DE-9IM is a standard used to describe spatial relationships between two geometries and can be referenced at https://en.wikipedia.org/wiki/DE-9IM.

Examples of how to use the Relate method can be found here. All of the predefined relational operations can be defined (including Intersect, Within, Contains, Crosses, Disjoint, Overlaps, Equals and Touches).

Example
Determine relationship between two geometries
```// set up some geometries

// points
MapPoint point0 = MapPointBuilderEx.CreateMapPoint(0, 0, SpatialReferences.WGS84);
MapPoint point1 = MapPointBuilderEx.CreateMapPoint(1, 1, SpatialReferences.WGS84);
MapPoint point2 = MapPointBuilderEx.CreateMapPoint(-5, 5, SpatialReferences.WGS84);

// multipoint
List<MapPoint> points = new List<MapPoint>() { point0, point1, point2 };
Multipoint multipoint = MultipointBuilderEx.CreateMultipoint(points, SpatialReferences.WGS84);

// polygon
List<Coordinate2D> polygonCoords = new List<Coordinate2D>()
{
new Coordinate2D(-10, 0),
new Coordinate2D(0, 10),
new Coordinate2D(10, 0),
new Coordinate2D(-10, 0)
};
Polygon polygon = PolygonBuilderEx.CreatePolygon(polygonCoords, SpatialReferences.WGS84);

// polylines
Polyline polyline1 = PolylineBuilderEx.CreatePolyline(LineBuilderEx.CreateLineSegment(new Coordinate2D(-9.1, 0.1), new Coordinate2D(0, 9)), SpatialReferences.WGS84);
Polyline polyline2 = PolylineBuilderEx.CreatePolyline(LineBuilderEx.CreateLineSegment(new Coordinate2D(-5, 5), new Coordinate2D(0, 5)), SpatialReferences.WGS84);
Polyline polyline3 = PolylineBuilderEx.CreatePolyline(LineBuilderEx.CreateLineSegment(new Coordinate2D(2.09, -2.04), new Coordinate2D(5, 10)), SpatialReferences.WGS84);
Polyline polyline4 = PolylineBuilderEx.CreatePolyline(LineBuilderEx.CreateLineSegment(new Coordinate2D(10, -5), new Coordinate2D(10, 5)), SpatialReferences.WGS84);

List<Segment> segments = new List<Segment>()
{
LineBuilderEx.CreateLineSegment(new Coordinate2D(5.05, -2.87), new Coordinate2D(6.35, 1.57)),
LineBuilderEx.CreateLineSegment(new Coordinate2D(6.35, 1.57), new Coordinate2D(4.13, 2.59)),
LineBuilderEx.CreateLineSegment(new Coordinate2D(4.13, 2.59), new Coordinate2D(5, 5))
};
Polyline polyline5 = PolylineBuilderEx.CreatePolyline(segments, SpatialReferences.WGS84);

segments.Add(LineBuilderEx.CreateLineSegment(new Coordinate2D(5, 5), new Coordinate2D(10, 10)));

Polyline polyline6 = PolylineBuilderEx.CreatePolyline(segments, SpatialReferences.WGS84);
Polyline polyline7 = PolylineBuilderEx.CreatePolyline(polyline5);
Polyline polyline8 = PolylineBuilderEx.CreatePolyline(LineBuilderEx.CreateLineSegment(new Coordinate2D(5, 5), new Coordinate2D(10, 10)), SpatialReferences.WGS84);

segments.Clear();
segments.Add(LineBuilderEx.CreateLineSegment(new Coordinate2D(0.6, 3.5), new Coordinate2D(0.7, 7)));
segments.Add(LineBuilderEx.CreateLineSegment(new Coordinate2D(0.7, 7), new Coordinate2D(3, 9)));

Polyline polyline9 = PolylineBuilderEx.CreatePolyline(segments, SpatialReferences.WGS84);

// now do the Related tests

// Interior/Interior Intersects
string scl = "T********";
bool related = GeometryEngine.Instance.Relate(polygon, polyline1, scl);     // related = true
related = GeometryEngine.Instance.Relate(point0, point1, scl);              // related = false
related = GeometryEngine.Instance.Relate(point0, multipoint, scl);          // related = true
related = GeometryEngine.Instance.Relate(multipoint, polygon, scl);         // related = true
related = GeometryEngine.Instance.Relate(multipoint, polyline1, scl);       // related = false
related = GeometryEngine.Instance.Relate(polyline2, point2, scl);           // related = false
related = GeometryEngine.Instance.Relate(point1, polygon, scl);             // related = true

// Interior/Boundary Intersects
scl = "*T*******";
related = GeometryEngine.Instance.Relate(polygon, polyline2, scl);          // related = true
related = GeometryEngine.Instance.Relate(polygon, polyline3, scl);          // related = false
related = GeometryEngine.Instance.Relate(point1, polygon, scl);             // related = false

// Boundary/Boundary Interior intersects
scl = "***T*****";
related = GeometryEngine.Instance.Relate(polygon, polyline4, scl);          // related = true

// Overlaps Dim1
scl = "1*T***T**";
related = GeometryEngine.Instance.Relate(polygon, polyline5, scl);          // related = true

// Crosses Area/Line (LineB crosses PolygonA)
scl = "1020F1102";
related = GeometryEngine.Instance.Relate(polygon, polyline6, scl);          // related = false
related = GeometryEngine.Instance.Relate(polygon, polyline9, scl);          // related = true

// Boundary/Boundary Touches
scl = "F***T****";
related = GeometryEngine.Instance.Relate(polygon, polyline7, scl);          // related = false
related = GeometryEngine.Instance.Relate(polygon, polyline8, scl);          // related = true
```
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.