edu.umn.cs.spatialHadoop.operations

Class ConvexHull

java.lang.Object

edu.umn.cs.spatialHadoop.operations.ConvexHull

public class ConvexHull
extends java.lang.Object

Computes the convex hull for a set of shapes

Author:

Ahmed Eldawy

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConvexHull.ConvexHullFilter Filters partitions to remove ones that do not contribute to answer.
static class	ConvexHull.ConvexHullReducer
static class	ConvexHull.IdentityMapper An identity map function that returns values as-is with a null key.

Constructor Summary

Constructors

Constructor and Description
ConvexHull()

Method Summary

Methods

Modifier and Type	Method and Description
static void	convexHull(Path inFile, Path outFile, boolean overwrite) Computes the convex hull of an input file using a single machine algorithm.
static Point[]	convexHull(Point[] points) Computes the convex hull of a set of points using a divide and conquer in-memory algorithm.
static void	convexHullMapReduce(Path inFile, Path userOutPath, OperationsParams params)
static <S extends Point> void	convexHullStream(S point) Computes the convex hull by reading points from stream
static void	main(java.lang.String[] args)

Methods inherited from class java.lang.Object

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

Constructor Detail

ConvexHull

public ConvexHull()

Method Detail

convexHull

public static Point[] convexHull(Point[] points)

Computes the convex hull of a set of points using a divide and conquer in-memory algorithm. This function implements Andrew's modification to the Graham scan algorithm.

Parameters:

points -

Returns:

convexHull

public static void convexHull(Path inFile,
              Path outFile,
              boolean overwrite)
                       throws java.io.IOException

Computes the convex hull of an input file using a single machine algorithm. The output is written to the output file. If output file is null, the output is just thrown away.

Parameters:

inFile -

outFile -

overwrite -

Throws:

java.io.IOException

convexHullStream

public static <S extends Point> void convexHullStream(S point)
                             throws java.io.IOException

Computes the convex hull by reading points from stream

Parameters:

point -

Throws:

java.io.IOException

convexHullMapReduce

public static void convexHullMapReduce(Path inFile,
                       Path userOutPath,
                       OperationsParams params)
                                throws java.io.IOException

Throws:

java.io.IOException

main

public static void main(java.lang.String[] args)
                 throws java.io.IOException

Throws:

java.io.IOException