public class LineSequencer extends Object
A typical use case is to convert a set of unoriented geometric links from a linear network (e.g. such as block faces on a bus route) into a continuous oriented path through the network.
The input linestrings may form one or more connected sets.
The input linestrings should be correctly noded, or the results may
not be what is expected.
The computed output is a single MultiLineString
containing the ordered
linestrings in the sequence.
The sequencing employs the classic Eulerian path graph algorithm. Since Eulerian paths are not uniquely determined, further rules are used to make the computed sequence preserve as much as possible of the input ordering. Within a connected subset of lines, the ordering rules are:
isSequenceable()
method
will return false
.Constructor and Description |
---|
LineSequencer() |
Modifier and Type | Method and Description |
---|---|
void |
add(Collection geometries)
Adds a
Collection of Geometry s to be sequenced. |
void |
add(Geometry geometry)
Adds a
Geometry to be sequenced. |
Geometry |
getSequencedLineStrings()
Returns the
LineString or MultiLineString
built by the sequencing process, if one exists. |
boolean |
isSequenceable()
Tests whether the arrangement of linestrings has a valid
sequence.
|
static boolean |
isSequenced(Geometry geom)
Tests whether a
Geometry is sequenced correctly. |
static Geometry |
sequence(Geometry geom) |
public static boolean isSequenced(Geometry geom)
Geometry
is sequenced correctly.
LineString
s are trivially sequenced.
MultiLineString
s are checked for correct sequencing.
Otherwise, isSequenced
is defined
to be true
for geometries that are not lineal.geom
- the geometry to testtrue
if the geometry is sequenced or is not linealpublic void add(Collection geometries)
Collection
of Geometry
s to be sequenced.
May be called multiple times.
Any dimension of Geometry may be added; the constituent linework will be
extracted.geometries
- a Collection of geometries to addpublic void add(Geometry geometry)
Geometry
to be sequenced.
May be called multiple times.
Any dimension of Geometry may be added; the constituent linework will be
extracted.geometry
- the geometry to addpublic boolean isSequenceable()
true
if a valid sequence exists.public Geometry getSequencedLineStrings()
LineString
or MultiLineString
built by the sequencing process, if one exists.null
if a valid sequence does not existCopyright © 2022. All rights reserved.