edu.umn.cs.spatialHadoop.core

Class ZCurvePartitioner

java.lang.Object

edu.umn.cs.spatialHadoop.core.Partitioner

edu.umn.cs.spatialHadoop.core.ZCurvePartitioner

public class ZCurvePartitioner
extends Partitioner

Partition the space based on Z-curve.

Author:

Ahmed Eldawy

Field Summary

Fields

Modifier and Type	Field and Description
protected Rectangle	mbr MBR of the input file
protected static int	Resolution
protected long[]	zSplits Upper bound of all partitions

Constructor Summary

Constructors

Constructor and Description
ZCurvePartitioner() A default constructor to be able to dynamically instantiate it and deserialize it

Method Summary

Methods

Modifier and Type	Method and Description
static long	computeZ(Rectangle mbr, double x, double y) Computes the Z-order of a point relative to a containing rectangle
static long	computeZOrder(long x, long y) Computes the Z-order (Morton order) of a two-dimensional point.
void	createFromPoints(Rectangle mbr, Point[] points, int numPartitions) Populate this partitioner for a set of points and number of partitions
protected void	createFromZValues(long[] zValues, int partitions) Create a ZCurvePartitioner from a list of points
static Rectangle	getMBR(Rectangle mbr, long zMin, long zMax)
static java.awt.Rectangle	getMBRInteger(long zMin, long zMax) Compute the minimal bounding rectangle MBR of a range on the Z-curve.
CellInfo	getPartition(int id) Returns the details of a specific partition given its ID.
CellInfo	getPartitionAt(int index) Returns the detail of a partition given its position starting from zero and ending at partitionCount() - 1
int	getPartitionCount() Returns total number of partitions
int	overlapPartition(Shape shape) Returns only one overlapping partition.
void	overlapPartitions(Shape shape, ResultCollector<java.lang.Integer> matcher) Overlap a shape with partitions and calls a matcher for each overlapping partition.
void	readFields(java.io.DataInput in)
static void	uncomputeZ(Rectangle mbr, long z, Point outPoint) Reverse the computation of the Z-value and returns x and y dimensions
static long	unComputeZOrder(long morton)
static java.awt.Point	unComputeZOrder(long morton, java.awt.Point point)
void	write(java.io.DataOutput out)

Methods inherited from class edu.umn.cs.spatialHadoop.core.Partitioner

getPartitioner, setPartitioner

Methods inherited from class java.lang.Object

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

Field Detail

mbr

protected Rectangle mbr

MBR of the input file

zSplits

protected long[] zSplits

Upper bound of all partitions

Resolution

protected static final int Resolution

See Also:

Constant Field Values

Constructor Detail

ZCurvePartitioner

public ZCurvePartitioner()

A default constructor to be able to dynamically instantiate it and deserialize it

Method Detail

createFromPoints

public void createFromPoints(Rectangle mbr,
                    Point[] points,
                    int numPartitions)

Description copied from class: Partitioner

Populate this partitioner for a set of points and number of partitions

Specified by:

createFromPoints in class Partitioner

createFromZValues

protected void createFromZValues(long[] zValues,
                     int partitions)

Create a ZCurvePartitioner from a list of points

Parameters:

vsample -

inMBR -

partitions -

computeZ

public static long computeZ(Rectangle mbr,
            double x,
            double y)

Computes the Z-order of a point relative to a containing rectangle

Parameters:

mbr -

x -

y -

Returns:

uncomputeZ

public static void uncomputeZ(Rectangle mbr,
              long z,
              Point outPoint)

Reverse the computation of the Z-value and returns x and y dimensions

Parameters:

mbr -

x -

y -

computeZOrder

public static long computeZOrder(long x,
                 long y)

Computes the Z-order (Morton order) of a two-dimensional point.

Parameters:

x - - integer value of the x-axis (cannot exceed Integer.MAX_VALUE)

y - - integer value of the y-axis (cannot exceed Integer.MAX_VALUE)

Returns:

unComputeZOrder

public static java.awt.Point unComputeZOrder(long morton,
                             java.awt.Point point)

unComputeZOrder

public static long unComputeZOrder(long morton)

getMBRInteger

public static java.awt.Rectangle getMBRInteger(long zMin,
                               long zMax)

Compute the minimal bounding rectangle MBR of a range on the Z-curve. Notice that getting the MBR of the two end points does not always work.

Parameters:

zMin -

zMax -

Returns:

getMBR

public static Rectangle getMBR(Rectangle mbr,
               long zMin,
               long zMax)

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Throws:

java.io.IOException

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Throws:

java.io.IOException

getPartitionCount

public int getPartitionCount()

Description copied from class: Partitioner

Returns total number of partitions

Specified by:

getPartitionCount in class Partitioner

Returns:

overlapPartitions

public void overlapPartitions(Shape shape,
                     ResultCollector<java.lang.Integer> matcher)

Description copied from class: Partitioner

Overlap a shape with partitions and calls a matcher for each overlapping partition.

Specified by:

overlapPartitions in class Partitioner

overlapPartition

public int overlapPartition(Shape shape)

Description copied from class: Partitioner

Returns only one overlapping partition. If the given shape overlaps more than one partitions, the partitioner returns only one of them according to its own criteria. If it does not overlap any partition, it returns -1 which is an invalid partition ID.

Specified by:

overlapPartition in class Partitioner

Returns:

getPartitionAt

public CellInfo getPartitionAt(int index)

Description copied from class: Partitioner

Returns the detail of a partition given its position starting from zero and ending at partitionCount() - 1

Specified by:

getPartitionAt in class Partitioner

Returns:

getPartition

public CellInfo getPartition(int id)

Description copied from class: Partitioner

Returns the details of a specific partition given its ID.

Specified by:

getPartition in class Partitioner

Returns: