Class LocationIndexedLine

Supports linear referencing along a linear Geometry using LinearLocations as the index.

Inheritance

object

LocationIndexedLine

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: NetTopologySuite.LinearReferencing

Assembly: NetTopologySuite.dll

Syntax

public class LocationIndexedLine

Constructors

LocationIndexedLine(Geometry)

Constructs an object which allows linear referencing along a given linear Geometry.

Declaration

public LocationIndexedLine(Geometry linearGeom)

Parameters

Type	Name	Description
Geometry	linearGeom	The linear geometry to reference alo

Properties

EndIndex

Returns the index of the end of the line.

Declaration

public LinearLocation EndIndex { get; }

Property Value

Type	Description
LinearLocation

StartIndex

Returns the index of the start of the line.

Declaration

public LinearLocation StartIndex { get; }

Property Value

Type	Description
LinearLocation

Methods

ClampIndex(LinearLocation)

Computes a valid index for this line by clamping the given index to the valid range of index values.

Declaration

public LinearLocation ClampIndex(LinearLocation index)

Parameters

Type	Name	Description
LinearLocation	index

Returns

Type	Description
LinearLocation	A valid index value.

ExtractLine(LinearLocation, LinearLocation)

Computes the LineString for the interval on the line between the given indices. If the start location is after the end location, the computed linear geometry has reverse orientation to the input line.

Declaration

public Geometry ExtractLine(LinearLocation startIndex, LinearLocation endIndex)

Parameters

Type	Name	Description
LinearLocation	startIndex	The index of the start of the interval.
LinearLocation	endIndex	The index of the end of the interval.

Returns

Type	Description
Geometry	The linear interval between the indices.

ExtractPoint(LinearLocation)

Computes the Coordinatefor the point on the line at the given index. If the index is out of range, the first or last point on the line will be returned.

Declaration

public Coordinate ExtractPoint(LinearLocation index)

Parameters

Type	Name	Description
LinearLocation	index	The index of the desired point.

Returns

Type	Description
Coordinate	The Coordinate at the given index.

Remarks

The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.

ExtractPoint(LinearLocation, double)

Computes the Coordinate for the point on the line at the given index, offset by the given distance. If the index is out of range the first or last point on the line will be returned.

The computed point is offset to the left of the line if the offset distance is positive, to the right if negative.

The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.

Declaration

public Coordinate ExtractPoint(LinearLocation index, double offsetDistance)

Parameters

Type	Name	Description
LinearLocation	index	The index of the desired point
double	offsetDistance	The distance the point is offset from the segment (positive is to the left, negative is to the right)

Returns

Type	Description
Coordinate	The Coordinate at the given index

ExtractPoint(double, double)

Computes the Coordinate for the point on the line at the given index, offset by the given distance.

Declaration

public Coordinate ExtractPoint(double index, double offsetDistance)

Parameters

Type	Name	Description
double	index	The index of the desired point
double	offsetDistance	The distance the point is offset from the segment (positive is to the left, negative is to the right)

Returns

Type	Description
Coordinate	The Coordinate at the given index

Remarks

If the index is out of range the first or last point on the line will be returned. The computed point is offset to the left of the line if the offset distance is positive, to the right if negative. The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.

IndexOf(Coordinate)

Computes the index for a given point on the line. The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use Project(Coordinate) to compute a guaranteed result for points which may be far from the line.

Declaration

public LinearLocation IndexOf(Coordinate pt)

Parameters

Type	Name	Description
Coordinate	pt	A point on the line.

Returns

Type	Description
LinearLocation	The index of the point.

See Also

Project(Coordinate)

IndexOfAfter(Coordinate, LinearLocation)

Finds the index for a point on the line which is greater than the given index. If no such index exists, returns minIndex.

Declaration

public LinearLocation IndexOfAfter(Coordinate pt, LinearLocation minIndex)

Parameters

Type	Name	Description
Coordinate	pt	A point on the line
LinearLocation	minIndex	The value the returned index must be greater than

Returns

Type	Description
LinearLocation	The index of the point greater than the given minimum index

Remarks

This method can be used to determine all indexes for a point which occurs more than once on a non-simple line. It can also be used to disambiguate cases where the given point lies slightly off the line and is equidistant from two different points on the line.

The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use Project(Coordinate) to compute a guaranteed result for points which may be far from the line.

See Also

Project(Coordinate)

IndicesOf(Geometry)

Computes the indices for a subline of the line. (The subline must conform to the line; that is, all vertices in the subline (except possibly the first and last) must be vertices of the line and occur in the same order).

Declaration

public LinearLocation[] IndicesOf(Geometry subLine)

Parameters

Type	Name	Description
Geometry	subLine	A subLine of the line.

Returns

Type	Description
LinearLocation[]	A pair of indices for the start and end of the subline.

IsValidIndex(LinearLocation)

Tests whether an index is in the valid index range for the line.

Declaration

public bool IsValidIndex(LinearLocation index)

Parameters

Type	Name	Description
LinearLocation	index	The index to test.

Returns

Type	Description
bool	true if the index is in the valid range.

Project(Coordinate)

Computes the index for the closest point on the line to the given point. If more than one point has the closest distance the first one along the line is returned. (The point does not necessarily have to lie precisely on the line.)

Declaration

public LinearLocation Project(Coordinate pt)

Parameters

Type	Name	Description
Coordinate	pt	A point on the line.

Returns

Type	Description
LinearLocation	The index of the point.