com.revolsys.gis.algorithm

Class LocationOfPoint

java.lang.Object

com.revolsys.gis.algorithm.LocationOfPoint

public class LocationOfPoint
extends Object

Computes the LineStringLocation of the point on a LineString nearest a given point. The nearest point is not necessarily unique, but this class always computes the nearest point closest to the start of the linestring.

Constructor Summary

Constructors

Constructor and Description
LocationOfPoint(LineString line)

Method Summary

Methods

Modifier and Type	Method and Description
static LineStringLocation	locate(LineString line, Point inputPt)
LineStringLocation	locate(Point inputPt) Find the nearest location along a LineString to a given point.
LineStringLocation	locateAfter(Point inputPt, LineStringLocation minLocation) Find the nearest location along a LineString to a given point after the specified minimum LineStringLocation.
static double	segmentFraction(Point p0, Point p1, Point inputPt)
static double	segmentFraction(Segment segment, Point inputPt)

Methods inherited from class java.lang.Object

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

Constructor Detail

LocationOfPoint

public LocationOfPoint(LineString line)

Method Detail

locate

public static LineStringLocation locate(LineString line,
                        Point inputPt)

segmentFraction

public static double segmentFraction(Point p0,
                     Point p1,
                     Point inputPt)

segmentFraction

public static double segmentFraction(Segment segment,
                     Point inputPt)

locate

public LineStringLocation locate(Point inputPt)

Find the nearest location along a LineString to a given point.

Parameters:

inputPt - the coordinate to locate

Returns:

the location of the nearest point

locateAfter

public LineStringLocation locateAfter(Point inputPt,
                             LineStringLocation minLocation)

Find the nearest location along a LineString to a given point after the specified minimum LineStringLocation. 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

minLocation - the minimum location for the point location

Returns:

the location of the nearest point