net.imglib2.kdtree

Class KDTreePositions

java.lang.Object

net.imglib2.kdtree.KDTreePositions

public abstract class KDTreePositions
extends Object

Stores the positions of the nodes in a KDTree and provides access to them.

Currently, there are two implementations:

• Nested stores the positions as a double[][] where positions[d][i] is dimension d of the i-th point. This allows for a total of 2^31-8 nodes but doesn't keep the positions contiguous in memory.
• Flat stores the positions as a double[] where positions[d + i*n] is dimension d of the i-th point, with n the number of dimensions. This means that the positions are contiguous in memory but the number of nodes is limited to (2^31-8)/n.

asNestedArray() returns positions in nested double[][] (which is created if class is Flat). asFlatArray() returns flat double[] if class is Flat, otherwise null.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	KDTreePositions.PositionsLayout With NESTED layout, positions are stored as a nested double[][] array where positions[d][i] is dimension d of the i-th point.

Method Summary

Modifier and Type	Method and Description
abstract double[]	asFlatArray() Get positions of points in the tree as a flat double[] array where positions[d + i*n] is dimension d of the i-th point.
abstract double[][]	asNestedArray() Get positions of points in the tree as a nested double[][] array where positions[d][i] is dimension d of the i-th point.
static KDTreePositions	createFlat(double[] positions, int numDimensions) Create KDTreePositions with FLAT layout().
static KDTreePositions	createNested(double[][] positions) Create KDTreePositions with NESTED layout().
abstract double	get(int i, int d) Get the coordinates of the node i in dimension d.
abstract KDTreePositions.PositionsLayout	layout() Get the internal layout of positions.
int	numDimensions()
int	numPoints()

Methods inherited from class java.lang.Object

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

Method Detail

get

public abstract double get(int i,
                           int d)

Get the coordinates of the node i in dimension d.

Returns:

the coordinate

asFlatArray

public abstract double[] asFlatArray()

Get positions of points in the tree as a flat double[] array where positions[d + i*n] is dimension d of the i-th point.

For serialisation and usage by the tree.

Internal storage may be a NESTED double[][] array. In this case, flatPositions() returns null.

asNestedArray

public abstract double[][] asNestedArray()

Get positions of points in the tree as a nested double[][] array where positions[d][i] is dimension d of the i-th point.

For serialisation and usage by the tree.

Internal storage may be flattened into single double[] array. In this case, the nested double[][] array is created here.

layout

public abstract KDTreePositions.PositionsLayout layout()

Get the internal layout of positions.

Positions are stored in either FLAT or NESTED layout. With NESTED layout, positions are stored as a nested double[][] array where positions[d][i] is dimension d of the i-th point. With FLAT layout, positions are stored as a flat double[] array, where positions[d + i*n] is dimension d of the i-th point, with n the number of dimensions.

numDimensions

public int numDimensions()

Returns:

dimensionality of points in the tree

numPoints

public int numPoints()

Returns:

number of points in the tree

createNested

public static KDTreePositions createNested(double[][] positions)

Create KDTreePositions with NESTED layout().

createFlat

public static KDTreePositions createFlat(double[] positions,
                                         int numDimensions)

Create KDTreePositions with FLAT layout().