Polygon (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- de.lmu.ifi.dbs.elki.data.spatial.Polygon

All Implemented Interfaces:

SpatialComparable, Iterable<Vector>
```
public class Polygon
extends Object
implements Iterable<Vector>, SpatialComparable
```
Class representing a simple polygon. While you can obviously store non-simple polygons in this, note that many of the supplied methods will assume that the polygons are simple.

Field Summary

Fields
Modifier and Type Field and Description

private double[] max
Maximum values

private double[] min
Minimum values

private List<Vector> points
The actual points

Fields
Modifier and Type	Field and Description
`private double[]`	`max` Maximum values
`private double[]`	`min` Minimum values
`private List<Vector>`	`points` The actual points

Constructor Summary

Constructors
Constructor and Description
`Polygon(List<Vector> points)` Constructor.
`Polygon(List<Vector> points, double minx, double maxx, double miny, double maxy)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`appendToBuffer(StringBuilder buf)` Append the polygon to the buffer.
`boolean`	`containsPoint2D(Vector v)` Point in polygon test, based on http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html by W.
`ListIterator<Vector>`	`descendingIterator()` Return an iterator that iterates the list backwards.
`Vector`	`get(int idx)` Get a vector by index.
`int`	`getDimensionality()` Returns the dimensionality of the object.
`double`	`getMax(int dimension)` Returns the maximum coordinate at the specified dimension.
`double`	`getMin(int dimension)` Returns the minimum coordinate at the specified dimension.
`boolean`	`intersects2DIncomplete(Polygon other)` Simple polygon intersection test.
`Iterator<Vector>`	`iterator()`
`ListIterator<Vector>`	`listIterator()` Get a list iterator.
`int`	`size()` Get the polygon length.
`int`	`testClockwise()` Test polygon orientation.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - points
```
private List<Vector> points
```
    The actual points
  - min
```
private double[] min
```
    Minimum values
  - max
```
private double[] max
```
    Maximum values
- Constructor Detail
  - Polygon
```
public Polygon(List<Vector> points)
```
    Constructor.
    
    Parameters:
    points - Polygon points
  - Polygon
```
public Polygon(List<Vector> points,
       double minx,
       double maxx,
       double miny,
       double maxy)
```
- Method Detail
  - iterator
```
public Iterator<Vector> iterator()
```
    Specified by:
    
    iterator in interface Iterable<Vector>
  - listIterator
```
public ListIterator<Vector> listIterator()
```
    Get a list iterator.
    
    Returns:
    List iterator.
  - descendingIterator
```
public ListIterator<Vector> descendingIterator()
```
    Return an iterator that iterates the list backwards.
    
    Returns:
    Reversed iterator
  - appendToBuffer
```
public void appendToBuffer(StringBuilder buf)
```
    Append the polygon to the buffer.
    
    Parameters:
    buf - Buffer to append to
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - size
```
public int size()
```
    Get the polygon length.
    
    Returns:
    Polygon length
  - get
```
public Vector get(int idx)
```
    Get a vector by index.
    
    Parameters:
    idx - Index to get
    
    Returns:
    Vector
  - getDimensionality
```
public int getDimensionality()
```
    Description copied from interface: SpatialComparable
    
    Returns the dimensionality of the object.
    
    Specified by:
    
    getDimensionality in interface SpatialComparable
    
    Returns:
    the dimensionality
  - getMin
```
public double getMin(int dimension)
```
    Description copied from interface: SpatialComparable
    
    Returns the minimum coordinate at the specified dimension.
    
    Specified by:
    
    getMin in interface SpatialComparable
    
    Parameters:
    dimension - the dimension for which the coordinate should be returned, where 0 ≤ dimension < getDimensionality()
    
    Returns:
    the minimum coordinate at the specified dimension
  - getMax
```
public double getMax(int dimension)
```
    Description copied from interface: SpatialComparable
    
    Returns the maximum coordinate at the specified dimension.
    
    Specified by:
    
    getMax in interface SpatialComparable
    
    Parameters:
    dimension - the dimension for which the coordinate should be returned, where 0 ≤ dimension < getDimensionality()
    
    Returns:
    the maximum coordinate at the specified dimension
  - testClockwise
```
public int testClockwise()
```
    Test polygon orientation.
    
    Returns:
    -1, 0, 1 for counterclockwise, undefined and clockwise.
  - intersects2DIncomplete
```
public boolean intersects2DIncomplete(Polygon other)
```
    Simple polygon intersection test.
    FIXME: while this is found on some web pages as "solution" and satisfies or needs, it clearly is not correct; not even for convex polygons: Consider a cross where the two bars are made out of four vertices each. No vertex is inside the other polygon, yet they intersect. I knew this before writing this code, but this O(n) code was the simplest thing to come up with, and it would work for our current data sets. A way to fix this is to augment it with the obvious O(n*n) segment intersection test. (Note that you will still need to test for point containment, since the whole polygon could be contained in the other!)
    
    Parameters:
    other - Other polygon
    
    Returns:
    True when the polygons intersect
  - containsPoint2D
```
public boolean containsPoint2D(Vector v)
```
    Point in polygon test, based on http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html by W. Randolph Franklin
    
    Parameters:
    v - Point to test
    
    Returns:
    True when contained.

Class Polygon

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

points

min

max

Constructor Detail

Polygon

Polygon

Method Detail

iterator

listIterator

descendingIterator

appendToBuffer

toString

size

get

getDimensionality

getMin

getMax

testClockwise

intersects2DIncomplete

containsPoint2D