Class IsSimpleOp

Tests whether a Geometry is simple. In general, the SFS specification of simplicity follows the rule:

• A Geometry is simple if and only if the only self-intersections are at boundary points.

Inheritance

Object

IsSimpleOp

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: NetTopologySuite.Operation

Assembly: NetTopologySuite.dll

Syntax

[Obsolete("Replaced by NetTopologySuite.Operation.Valid.IsSimpleOp")]
public class IsSimpleOp

Remarks

Simplicity is defined for each Geometry} subclass as follows:

• Valid IPolygonal geometries are simple by definition, so IsSimple trivially returns true.
  (Note: this means that IsSimple cannot be used to test for (invalid) self-intersections in Polygons. In order to check if a Polygonal geometry has self-intersections, use IsValid).
• ILineal geometries are simple if and only if they do not self-intersect at interior points (i.e. points other than boundary points). This is equivalent to saying that no two linear components satisfy the SFS Touches(Geometry) predicate.
• Zero-dimensional (IPuntal) geometries are simple if and only if they have no repeated points.
• Empty Geometrys are always simple by definition.

For ILineal geometries the evaluation of simplicity can be customized by supplying a IBoundaryNodeRule to define how boundary points are determined. The default is the SFS-standard NetTopologySuite.Algorithm.BoundaryNodeRules.Mod2BoundaryNodeRule. Note that under the Mod-2 rule, closed LineStrings (rings) will never satisfy the touches predicate at their endpoints, since these are interior points, not boundary points. If it is required to test whether a set of LineStrings touch only at their endpoints, use IsSimpleOp with EndpointBoundaryRule. For example, this can be used to validate that a set of lines form a topologically valid linear network.

Constructors

IsSimpleOp(Geometry)

Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule

Declaration

public IsSimpleOp(Geometry geom)

Parameters

Type	Name	Description
Geometry	geom	The geometry to test

IsSimpleOp(Geometry, IBoundaryNodeRule)

Creates a simplicity checker using a given IBoundaryNodeRule

Declaration

public IsSimpleOp(Geometry geom, IBoundaryNodeRule boundaryNodeRule)

Parameters

Type	Name	Description
Geometry	geom	The geometry to test
IBoundaryNodeRule	boundaryNodeRule	The rule to use

Properties

NonSimpleLocation

Gets a coordinate for the location where the geometry fails to be simple. (i.e. where it has a non-boundary self-intersection). IsSimple() must be called before this location is accessed

Declaration

public Coordinate NonSimpleLocation { get; }

Property Value

Type	Description
Coordinate	a coordinate for the location of the non-boundary self-intersection or null if the geometry is simple

Methods

IsSimple()

Tests whether the geometry is simple.

Declaration

public bool IsSimple()

Returns

Type	Description
Boolean	true if the geometry is simple