Package uk.ac.rdg.resc.edal.geometry

Class LineString

java.lang.Object

uk.ac.rdg.resc.edal.geometry.LineString

public final class LineString
extends Object

Represents a path through a coordinate system. The path consists of a set of linear path elements, drawn between control points.

Author:

Jon, Guy Griffiths

Constructor Summary

Constructors

Constructor	Description
LineString(String lineStringSpec, org.opengis.referencing.crs.CoordinateReferenceSystem crs)	Constructs a LineString from a line string in the form.

Method Summary

Modifier and Type	Method	Description
double	getControlPointDistanceKm(int index)	Returns the fractional distance along the line string to the control point with the given index.
List<HorizontalPosition>	getControlPoints()	Returns the list of control points along this line string.
org.opengis.referencing.crs.CoordinateReferenceSystem	getCoordinateReferenceSystem()
double	getPathLength()
List<HorizontalPosition>	getPointsOnPath(int n)	Returns a list of n points along the path defined by this line string.

Methods inherited from class java.lang.Object

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

Constructor Detail

LineString

public LineString(String lineStringSpec,
                  org.opengis.referencing.crs.CoordinateReferenceSystem crs)
           throws InvalidLineStringException,
                  InvalidCrsException

Constructs a LineString from a line string in the form.

Parameters:

lineStringSpec - the line string as specified in the form "x1 y1, x2 y2, x3 y3".

crs - The coordinate reference system for the line string's coordinates

Throws:

InvalidLineStringException - if the line string is not correctly specified.

InvalidCrsException

NullPointerException - if crsHelper == null

Method Detail

getControlPoints

public List<HorizontalPosition> getControlPoints()

Returns the list of control points along this line string.

Returns:

an unmodifiable list of control points.

getControlPointDistanceKm

public double getControlPointDistanceKm(int index)

Returns the fractional distance along the line string to the control point with the given index.

Parameters:

index - The index of the control point. An index of zero represents the start of the line string.

Returns:

the distance in km along the whole line string to the control point

Throws:

IndexOutOfBoundsException - if index < 0 || index >= number of control points

getPathLength

public double getPathLength()

Returns:

The total path length, in km

getPointsOnPath

public List<HorizontalPosition> getPointsOnPath(int n)

Returns a list of n points along the path defined by this line string. The first point will be the first control point; the last point will be the last control point. Intermediate points are linearly interpolated between the control points. Note that it is not guaranteed that the intermediate control points will be contained in this list. TODO Add the control points to this list, in the correct location.

Parameters:

n - The number of points to return

Returns:

an unmodifiable list of n points that lie on this path.

Throws:

IllegalArgumentException - if numPoints < 2

getCoordinateReferenceSystem

public org.opengis.referencing.crs.CoordinateReferenceSystem getCoordinateReferenceSystem()