Package org.locationtech.jts.linearref

Class LengthIndexOfPoint

java.lang.Object

org.locationtech.jts.linearref.LengthIndexOfPoint

class LengthIndexOfPoint
extends java.lang.Object

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

Field Summary

Fields

Modifier and Type	Field	Description
private Geometry	linearGeom

Constructor Summary

Constructors

Constructor	Description
LengthIndexOfPoint(Geometry linearGeom)

Method Summary

Modifier and Type	Method	Description
double	indexOf(Coordinate inputPt)	Find the nearest location along a linear Geometry to a given point.
static double	indexOf(Geometry linearGeom, Coordinate inputPt)
double	indexOfAfter(Coordinate inputPt, double minIndex)	Finds the nearest index along the linear Geometry to a given Coordinate after the specified minimum index.
static double	indexOfAfter(Geometry linearGeom, Coordinate inputPt, double minIndex)
private double	indexOfFromStart(Coordinate inputPt, double minIndex)
private double	segmentNearestMeasure(LineSegment seg, Coordinate inputPt, double segmentStartMeasure)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

linearGeom

private Geometry linearGeom

Constructor Detail

LengthIndexOfPoint

public LengthIndexOfPoint(Geometry linearGeom)

Method Detail

indexOf

public static double indexOf(Geometry linearGeom,
                             Coordinate inputPt)

indexOfAfter

public static double indexOfAfter(Geometry linearGeom,
                                  Coordinate inputPt,
                                  double minIndex)

indexOf

public double indexOf(Coordinate inputPt)

Find the nearest location along a linear Geometry to a given point.

Parameters:

inputPt - the coordinate to locate

Returns:

the location of the nearest point

indexOfAfter

public double indexOfAfter(Coordinate inputPt,
                           double minIndex)

Finds the nearest index along the linear Geometry to a given Coordinate after the specified minimum index. If possible the location returned will be strictly greater than the minLocation. If this is not possible, the value returned will equal minLocation. (An example where this is not possible is when minLocation = [end of line] ).

Parameters:

inputPt - the coordinate to locate

minIndex - the minimum location for the point location

Returns:

the location of the nearest point

indexOfFromStart

private double indexOfFromStart(Coordinate inputPt,
                                double minIndex)

segmentNearestMeasure

private double segmentNearestMeasure(LineSegment seg,
                                     Coordinate inputPt,
                                     double segmentStartMeasure)