Class Label

A Label indicates the topological relationship of a component of a topology graph to a given Geometry. This class supports labels for relationships to two Geometrys, which is sufficient for algorithms for binary operations. Topology graphs support the concept of labeling nodes and edges in the graph. The label of a node or edge specifies its topological relationship to one or more geometries. (In fact, since NTS operations have only two arguments labels are required for only two geometries). A label for a node or edge has one or two elements, depending on whether the node or edge occurs in one or both of the input Geometrys. Elements contain attributes which categorize the topological location of the node or edge relative to the parent Geometry; that is, whether the node or edge is in the interior, boundary or exterior of the Geometry. Attributes have a value from the set {Interior, Boundary, Exterior}. In a node each element has a single attribute On. For an edge each element has a triplet of attributes Left, On, Right. It is up to the client code to associate the 0 and 1 TopologyLocations with specific geometries.

Inheritance

object

Label

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: NetTopologySuite.GeometriesGraph

Assembly: NetTopologySuite.dll

Syntax

public class Label

Constructors

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Label(Location)

Construct a Label with a single location for both Geometries. Initialize the locations to Null.

Declaration

public Label(Location onLoc)

Parameters

Type	Name	Description
Location	onLoc	A location value

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Label(Location, Location, Location)

Construct a Label with On, Left and Right locations for both Geometries. Initialize the locations for both Geometries to the given values.

Declaration

public Label(Location onLoc, Location leftLoc, Location rightLoc)

Parameters

Type	Name	Description
Location	onLoc	A location value for On
Location	leftLoc	A location value for Left
Location	rightLoc	A location value for Right

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Label(Label)

Construct a Label with the same values as the argument Label.

Declaration

public Label(Label lbl)

Parameters

Type	Name	Description
Label	lbl	A `Label`

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Label(int, Location)

Construct a Label with a single location for both Geometries. Initialize the location for the Geometry index.

Declaration

public Label(int geomIndex, Location onLoc)

Parameters

Type	Name	Description
int	geomIndex	A geometry index, `0`, or `1`.
Location	onLoc	A location value for On

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Label(int, Location, Location, Location)

Construct a Label with On, Left and Right locations for both Geometries. Initialize the locations for the given Geometry index.

Declaration

public Label(int geomIndex, Location onLoc, Location leftLoc, Location rightLoc)

Parameters

Type	Name	Description
int	geomIndex	A geometry index, `0`, or `1`.
Location	onLoc	A location value for On
Location	leftLoc	A location value for Left
Location	rightLoc	A location value for Right

Properties

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GeometryCount

Declaration

public int GeometryCount { get; }

Property Value

Type	Description
int

Methods

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AllPositionsEqual(int, Location)

Declaration

public bool AllPositionsEqual(int geomIndex, Location loc)

Parameters

Type	Name	Description
int	geomIndex
Location	loc

Returns

Type	Description
bool

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Flip()

Performs Flip() on both TopologyLocations of this Label

Declaration

public void Flip()

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GetLocation(int)

Declaration

public Location GetLocation(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex

Returns

Type	Description
Location

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GetLocation(int, Position)

Declaration

public Location GetLocation(int geomIndex, Position posIndex)

Parameters

Type	Name	Description
int	geomIndex
Position	posIndex

Returns

Type	Description
Location

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GetLocation(int, Positions)

Declaration

[Obsolete("Use GetLocation(int, Topology.Location)")]
public Location GetLocation(int geomIndex, Positions posIndex)

Parameters

Type	Name	Description
int	geomIndex
Positions	posIndex

Returns

Type	Description
Location

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IsAnyNull(int)

Declaration

public bool IsAnyNull(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex

Returns

Type	Description
bool

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IsArea()

Declaration

public bool IsArea()

Returns

Type	Description
bool

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IsArea(int)

Declaration

public bool IsArea(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex

Returns

Type	Description
bool

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IsEqualOnSide(Label, int)

Declaration

public bool IsEqualOnSide(Label lbl, int side)

Parameters

Type	Name	Description
Label	lbl
int	side

Returns

Type	Description
bool

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IsLine(int)

Declaration

public bool IsLine(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex

Returns

Type	Description
bool

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IsNull(int)

Declaration

public bool IsNull(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex

Returns

Type	Description
bool

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Merge(Label)

Merge this label with another one. Merging updates any null attributes of this label with the attributes from lbl.

Declaration

public void Merge(Label lbl)

Parameters

Type	Name	Description
Label	lbl	The `Label` to merge

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SetAllLocations(int, Location)

Declaration

public void SetAllLocations(int geomIndex, Location _location)

Parameters

Type	Name	Description
int	geomIndex
Location	_location

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SetAllLocationsIfNull(Location)

Declaration

public void SetAllLocationsIfNull(Location _location)

Parameters

Type	Name	Description
Location	_location

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SetAllLocationsIfNull(int, Location)

Declaration

public void SetAllLocationsIfNull(int geomIndex, Location _location)

Parameters

Type	Name	Description
int	geomIndex
Location	_location

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SetLocation(int, Location)

Declaration

public void SetLocation(int geomIndex, Location _location)

Parameters

Type	Name	Description
int	geomIndex
Location	_location

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SetLocation(int, Position, Location)

Declaration

public void SetLocation(int geomIndex, Position posIndex, Location _location)

Parameters

Type	Name	Description
int	geomIndex
Position	posIndex
Location	_location

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SetLocation(int, Positions, Location)

Declaration

[Obsolete("Use SetLocation(int, Geometries.Position, Location)")]
public void SetLocation(int geomIndex, Positions posIndex, Location _location)

Parameters

Type	Name	Description
int	geomIndex
Positions	posIndex
Location	_location

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ToLine(int)

Converts one GeometryLocation to a Line location.

Declaration

public void ToLine(int geomIndex)

Parameters

Type	Name	Description
int	geomIndex	The index of the `TopologyLocation` to convert (`0` or `1`)

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ToLineLabel(Label)

Converts a Label to a Line label (that is, one with no side Location).

Declaration

public static Label ToLineLabel(Label label)

Parameters

Type	Name	Description
Label	label	Label to convert.

Returns

Type	Description
Label	Label as Line label.

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ToString()

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()