Namespace NetTopologySuite.LinearReferencing

Contains classes and interfaces implementing linear referencing on linear geometries

Linear Referencing

Linear Referencing is a way of defining positions along linear geometries (LineStrings and MultiLineStrings). It is used extensively in linear network systems. There are numerous possible Linear Referencing Methods which can be used to define positions along linear geometry. This package supports two:

Linear Location

A linear location is a triple (component index, segment index, segment fraction) which precisely specifies a point on a linear geometry. It allows for efficient mapping of the index value to actual coordinate values.

Length

The natural concept of using the length along the geometry to specify a position.

Package Specification

• Java Topology Suite Technical Specifications

Classes

ExtractLineByLocation

Extracts the subline of a linear Geometry between two LinearLocations on the line.

LengthIndexOfPoint

LengthIndexedLine

Supports linear referencing along a linear Geometry using the length along the line as the index. Negative length values are taken as measured in the reverse direction from the end of the geometry. Out-of-range index values are handled by clamping them to the valid range of values. Non-simple lines (i.e. which loop back to cross or touch themselves) are supported.

LengthLocationMap

Computes the LinearLocation for a given length along a linear Geometry Negative lengths are measured in reverse from end of the linear geometry. Out-of-range values are clamped.

LinearGeometryBuilder

Builds a linear geometry (LineString or MultiLineString) incrementally (point-by-point).

LinearIterator

An iterator over the components and coordinates of a linear geometry (LineStrings and MultiLineStrings.

LinearLocation

Represents a location along a LineString or MultiLineString.
The referenced geometry is not maintained within this location, but must be provided for operations which require it. Various methods are provided to manipulate the location value and query the geometry it references.

LocationIndexOfLine

Determines the location of a subline along a linear Geometry. The location is reported as a pair of LinearLocations. NOTE: Currently this algorithm is not guaranteed to return the correct substring in some situations where an endpoint of the test line occurs more than once in the input line. (However, the common case of a ring is always handled correctly).

LocationIndexOfPoint

Computes the LinearLocation of the point on a linear Geometrynearest a given Coordinate. The nearest point is not necessarily unique; this class always computes the nearest point closest to the start of the geometry.

LocationIndexedLine

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