com.vividsolutions.jts.geom
Class LineString

java.lang.Object
  com.vividsolutions.jts.geom.Geometry
      com.vividsolutions.jts.geom.LineString

All Implemented Interfaces:

Lineal, java.io.Serializable, java.lang.Cloneable, java.lang.Comparable

Direct Known Subclasses:

LinearRing

public class LineString
extends Geometry
implements Lineal

Models an OGC-style LineString. A LineString consists of a sequence of two or more vertices, along with all points along the linearly-interpolated curves (line segments) between each pair of consecutive vertices. Consecutive vertices may be equal. The line segments in the line may intersect each other (in other words, the linestring may "curl back" in itself and self-intersect. Linestrings with exactly two identical points are invalid.

A linestring must have either 0 or 2 or more points. If these conditions are not met, the constructors throw an IllegalArgumentException

Version:

1.7

See Also:

Serialized Form

Field Summary

protected CoordinateSequence

points The points of this LineString.

Fields inherited from class com.vividsolutions.jts.geom.Geometry

envelope, factory, SRID

Constructor Summary

LineString(Coordinate[] points, PrecisionModel precisionModel, int SRID)
Deprecated. Use GeometryFactory instead

LineString(CoordinateSequence points, GeometryFactory factory)
Constructs a LineString with the given points.

Method Summary

void	apply(CoordinateFilter filter) Performs an operation with or on this Geometry's coordinates.
void	apply(CoordinateSequenceFilter filter) Performs an operation on the coordinates in this Geometry's CoordinateSequences.
void	apply(GeometryComponentFilter filter) Performs an operation with or on this Geometry and its component Geometry's.
void	apply(GeometryFilter filter) Performs an operation with or on this Geometry and its subelement Geometrys (if any).
java.lang.Object	clone() Creates and returns a full copy of this LineString object.
protected int	compareToSameClass(java.lang.Object o) Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class.
protected int	compareToSameClass(java.lang.Object o, CoordinateSequenceComparator comp) Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class.
protected Envelope	computeEnvelopeInternal() Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty.
boolean	equalsExact(Geometry other, double tolerance) Returns true if the two Geometrys are exactly equal, up to a specified distance tolerance.
Geometry	getBoundary() Gets the boundary of this geometry.
int	getBoundaryDimension() Returns the dimension of this Geometrys inherent boundary.
Coordinate	getCoordinate() Returns a vertex of this Geometry (usually, but not necessarily, the first one).
Coordinate	getCoordinateN(int n)
Coordinate[]	getCoordinates() Returns an array containing the values of all the vertices for this geometry.
CoordinateSequence	getCoordinateSequence()
int	getDimension() Returns the dimension of this geometry.
Point	getEndPoint()
java.lang.String	getGeometryType() Returns the name of this object's com.vivid.jts.geom interface.
double	getLength() Returns the length of this LineString
int	getNumPoints() Returns the count of this Geometrys vertices.
Point	getPointN(int n)
Point	getStartPoint()
boolean	isClosed()
boolean	isCoordinate(Coordinate pt) Returns true if the given point is a vertex of this LineString.
boolean	isEmpty() Returns whether or not the set of points in this Geometry is empty.
protected boolean	isEquivalentClass(Geometry other) Returns whether the two Geometrys are equal, from the point of view of the equalsExact method.
boolean	isRing()
void	normalize() Normalizes a LineString.
Geometry	reverse() Creates a LineString whose coordinates are in the reverse order of this objects

Methods inherited from class com.vividsolutions.jts.geom.Geometry

buffer, buffer, buffer, checkNotGeometryCollection, compare, compareTo, compareTo, contains, convexHull, coveredBy, covers, crosses, difference, disjoint, distance, equal, equals, equals, equalsExact, equalsNorm, equalsTopo, geometryChanged, geometryChangedAction, getArea, getCentroid, getEnvelope, getEnvelopeInternal, getFactory, getGeometryN, getInteriorPoint, getNumGeometries, getPrecisionModel, getSRID, getUserData, hashCode, hasNonEmptyElements, hasNullElements, intersection, intersects, isGeometryCollection, isRectangle, isSimple, isValid, isWithinDistance, norm, overlaps, relate, relate, setSRID, setUserData, symDifference, toString, toText, touches, union, union, within

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

points

protected CoordinateSequence points

The points of this LineString.

Constructor Detail

LineString

public LineString(Coordinate[] points,
                  PrecisionModel precisionModel,
                  int SRID)

Deprecated. Use GeometryFactory instead

LineString

public LineString(CoordinateSequence points,
                  GeometryFactory factory)

Constructs a LineString with the given points.

Parameters:

points - the points of the linestring, or null to create the empty geometry. Consecutive points may not be equal.

Throws:

java.lang.IllegalArgumentException - if too few points are provided

Method Detail

getCoordinates

public Coordinate[] getCoordinates()

Description copied from class: Geometry

Returns an array containing the values of all the vertices for this geometry. If the geometry is a composite, the array will contain all the vertices for the components, in the order in which the components occur in the geometry.

In general, the array cannot be assumed to be the actual internal storage for the vertices. Thus modifying the array may not modify the geometry itself. Use the CoordinateSequence.setOrdinate(int, int, double) method (possibly on the components) to modify the underlying data. If the coordinates are modified, Geometry.geometryChanged() must be called afterwards.

Specified by:

getCoordinates in class Geometry

Returns:

the vertices of this Geometry

See Also:

Geometry.geometryChanged(), CoordinateSequence.setOrdinate(int, int, double)

getCoordinateSequence

public CoordinateSequence getCoordinateSequence()

getCoordinateN

public Coordinate getCoordinateN(int n)

getCoordinate

public Coordinate getCoordinate()

Description copied from class: Geometry

Returns a vertex of this Geometry (usually, but not necessarily, the first one). The returned coordinate should not be assumed to be an actual Coordinate object used in the internal representation.

Specified by:

getCoordinate in class Geometry

Returns:

a Coordinate which is a vertex of this Geometry.

getDimension

public int getDimension()

Description copied from class: Geometry

Returns the dimension of this geometry. The dimension of a geometry is is the topological dimension of its embedding in the 2-D Euclidean plane. In the JTS spatial model, dimension values are in the set {0,1,2}.

Note that this is a different concept to the dimension of the vertex Coordinates. The geometry dimension can never be greater than the coordinate dimension. For example, a 0-dimensional geometry (e.g. a Point) may have a coordinate dimension of 3 (X,Y,Z).

Specified by:

getDimension in class Geometry

Returns:

the topological dimension of this geometry.

getBoundaryDimension

public int getBoundaryDimension()

Description copied from class: Geometry

Returns the dimension of this Geometrys inherent boundary.

Specified by:

getBoundaryDimension in class Geometry

Returns:

the dimension of the boundary of the class implementing this interface, whether or not this object is the empty geometry. Returns Dimension.FALSE if the boundary is the empty geometry.

isEmpty

public boolean isEmpty()

Description copied from class: Geometry

Returns whether or not the set of points in this Geometry is empty.

Specified by:

isEmpty in class Geometry

Returns:

true if this Geometry equals the empty geometry

getNumPoints

public int getNumPoints()

Description copied from class: Geometry

Returns the count of this Geometrys vertices. The Geometry s contained by composite Geometrys must be Geometry's; that is, they must implement getNumPoints

Specified by:

getNumPoints in class Geometry

Returns:

the number of vertices in this Geometry

getPointN

public Point getPointN(int n)

getStartPoint

public Point getStartPoint()

getEndPoint

public Point getEndPoint()

isClosed

public boolean isClosed()

isRing

public boolean isRing()

getGeometryType

public java.lang.String getGeometryType()

Description copied from class: Geometry

Returns the name of this object's com.vivid.jts.geom interface.

Specified by:

getGeometryType in class Geometry

Returns:

the name of this Geometrys most specific com.vividsolutions.jts.geom interface

getLength

public double getLength()

Returns the length of this LineString

Overrides:

getLength in class Geometry

Returns:

the length of the linestring

getBoundary

public Geometry getBoundary()

Gets the boundary of this geometry. The boundary of a lineal geometry is always a zero-dimensional geometry (which may be empty).

Specified by:

getBoundary in class Geometry

Returns:

the boundary geometry

See Also:

Geometry.getBoundary()

reverse

public Geometry reverse()

Creates a LineString whose coordinates are in the reverse order of this objects

Specified by:

reverse in class Geometry

Returns:

a LineString with coordinates in the reverse order

isCoordinate

public boolean isCoordinate(Coordinate pt)

Returns true if the given point is a vertex of this LineString.

Parameters:

pt - the Coordinate to check

Returns:

true if pt is one of this LineString 's vertices

computeEnvelopeInternal

protected Envelope computeEnvelopeInternal()

Description copied from class: Geometry

Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty. Unlike getEnvelopeInternal, this method calculates the Envelope each time it is called; getEnvelopeInternal caches the result of this method.

Specified by:

computeEnvelopeInternal in class Geometry

Returns:

this Geometrys bounding box; if the Geometry is empty, Envelope#isNull will return true

equalsExact

public boolean equalsExact(Geometry other,
                           double tolerance)

Description copied from class: Geometry

Returns true if the two Geometrys are exactly equal, up to a specified distance tolerance. Two Geometries are exactly equal within a distance tolerance if and only if:

• they have the same structure
• they have the same values for their vertices, within the given tolerance distance, in exactly the same order.

This method does not test the values of the GeometryFactory, the SRID, or the userData fields.

To properly test equality between different geometries, it is usually necessary to Geometry.normalize() them first.

Specified by:

equalsExact in class Geometry

Parameters:

other - the Geometry with which to compare this Geometry

tolerance - distance at or below which two Coordinates are considered equal

Returns:

true if this and the other Geometry have identical structure and point values, up to the distance tolerance.

See Also:

Geometry.equalsExact(Geometry), Geometry.normalize(), Geometry.norm()

apply

public void apply(CoordinateFilter filter)

Description copied from class: Geometry

Performs an operation with or on this Geometry's coordinates. If this method modifies any coordinate values, Geometry.geometryChanged() must be called to update the geometry state. Note that you cannot use this method to modify this Geometry if its underlying CoordinateSequence's #get method returns a copy of the Coordinate, rather than the actual Coordinate stored (if it even stores Coordinate objects at all).

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry's coordinates

apply

public void apply(CoordinateSequenceFilter filter)

Description copied from class: Geometry

Performs an operation on the coordinates in this Geometry's CoordinateSequences. If the filter reports that a coordinate value has been changed, Geometry.geometryChanged() will be called automatically.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply

apply

public void apply(GeometryFilter filter)

Description copied from class: Geometry

Performs an operation with or on this Geometry and its subelement Geometrys (if any). Only GeometryCollections and subclasses have subelement Geometry's.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry (and its children, if it is a GeometryCollection).

apply

public void apply(GeometryComponentFilter filter)

Description copied from class: Geometry

Performs an operation with or on this Geometry and its component Geometry's. Only GeometryCollections and Polygons have component Geometry's; for Polygons they are the LinearRings of the shell and holes.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry.

clone

public java.lang.Object clone()

Creates and returns a full copy of this LineString object. (including all coordinates contained by it).

Overrides:

clone in class Geometry

Returns:

a clone of this instance

normalize

public void normalize()

Normalizes a LineString. A normalized linestring has the first point which is not equal to it's reflected point less than the reflected point.

Specified by:

normalize in class Geometry

isEquivalentClass

protected boolean isEquivalentClass(Geometry other)

Description copied from class: Geometry

Returns whether the two Geometrys are equal, from the point of view of the equalsExact method. Called by equalsExact . In general, two Geometry classes are considered to be "equivalent" only if they are the same class. An exception is LineString , which is considered to be equivalent to its subclasses.

Overrides:

isEquivalentClass in class Geometry

Parameters:

other - the Geometry with which to compare this Geometry for equality

Returns:

true if the classes of the two Geometry s are considered to be equal by the equalsExact method.

compareToSameClass

protected int compareToSameClass(java.lang.Object o)

Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications

compareToSameClass

protected int compareToSameClass(java.lang.Object o,
                                 CoordinateSequenceComparator comp)

Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class. using the given CoordinateSequenceComparator.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

comp - a CoordinateSequenceComparator

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications