cds.healpix.fillingcurve

Class ZOrderCurve3D

java.lang.Object

cds.healpix.fillingcurve.ZOrderCurve3D

All Implemented Interfaces:

FillingCurve3D

public class ZOrderCurve3D
extends java.lang.Object
implements FillingCurve3D

Implementation of the 3d z-order curve based on lookup tables.

Author:

F.-X. Pineau

Field Summary

Fields

Modifier and Type	Field and Description
static ZOrderCurve3D	INSTANCE

Method Summary

Modifier and Type	Method and Description
long	hash2i00(long hash) Special case of FillingCurve3D.hash2ijk(long) in which the discretized coordinate along the vertical axis equals zero.
long	hash2ijk(long hash) Transforms the given space filling curve index (or hash value) into a single value from which it is straightforward to extract the associated 3d-coordinates using methods FillingCurve3D.ijk2i(long), FillingCurve3D.ijk2j(long) and FillingCurve3D.ijk2k(long).
long	i002hash(int i) Special case of FillingCurve3D.ijk2hash(int, int, int) in which the discretized coordinate along the vertical axis equals zero.
long	ijk2hash(int i, int j, int k) Transforms coordinates in a discretized 2d-space into a space filling curve index.
int	ijk2i(long ijk) Extract the discretized horizontal coordinates from the result of the method FillingCurve3D.hash2ijk(long).
int	ijk2j(long ijk) Extract the discretized vertical coordinates from the result of the method FillingCurve3D.hash2ijk(long).
int	ijk2k(long ijk) Extract the discretized depth coordinates from the result of the method FillingCurve3D.hash2ijk(long).

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final ZOrderCurve3D INSTANCE

Method Detail

ijk2hash

public long ijk2hash(int i,
                     int j,
                     int k)

Description copied from interface: FillingCurve3D

Transforms coordinates in a discretized 2d-space into a space filling curve index. This can be thought of as computing a hash value from 3d-coordinates.

Specified by:

ijk2hash in interface FillingCurve3D

Parameters:

i - discretized coordinate along the horizontal axis

j - discretized coordinate along the vertical axis

k - discretized coordinate along the depth axis

Returns:

the space filling curve index (or hash value) associated to the given discretized 3d-coordinates.

i002hash

public long i002hash(int i)

Description copied from interface: FillingCurve3D

Special case of FillingCurve3D.ijk2hash(int, int, int) in which the discretized coordinate along the vertical axis equals zero.

Specified by:

i002hash in interface FillingCurve3D

Parameters:

i - discretized coordinate along the horizontal axis

Returns:

the space filling curve index (or hash value) associated to the given discretized horizontal coordinate, assuming the discretized vertical coordinate equal zero.

hash2ijk

public long hash2ijk(long hash)

Description copied from interface: FillingCurve3D

Transforms the given space filling curve index (or hash value) into a single value from which it is straightforward to extract the associated 3d-coordinates using methods FillingCurve3D.ijk2i(long), FillingCurve3D.ijk2j(long) and FillingCurve3D.ijk2k(long).

Specified by:

hash2ijk in interface FillingCurve3D

Parameters:

hash - the space filling curve index (or hash value)

Returns:

a single value from which it is straightforward to extract the associated 3d-coordinates using methods FillingCurve3D.ijk2i(long), FillingCurve3D.ijk2j(long) and FillingCurve3D.ijk2k(long).

hash2i00

public long hash2i00(long hash)

Description copied from interface: FillingCurve3D

Special case of FillingCurve3D.hash2ijk(long) in which the discretized coordinate along the vertical axis equals zero.

Specified by:

hash2i00 in interface FillingCurve3D

Parameters:

hash - the space filling curve index (or hash value)

Returns:

a single value, knowing the vertical coordinate equals zero, from which it is straightforward to extract the associated horizontal coordinate using method FillingCurve3D.ijk2i(long).

ijk2i

public int ijk2i(long ijk)

Description copied from interface: FillingCurve3D

Extract the discretized horizontal coordinates from the result of the method FillingCurve3D.hash2ijk(long).

Specified by:

ijk2i in interface FillingCurve3D

Parameters:

ijk - result of the method FillingCurve3D.hash2ijk(long)

Returns:

the discretized horizontal coordinate stored in the given parameter ijk

ijk2j

public int ijk2j(long ijk)

Description copied from interface: FillingCurve3D

Extract the discretized vertical coordinates from the result of the method FillingCurve3D.hash2ijk(long).

Specified by:

ijk2j in interface FillingCurve3D

Parameters:

ijk - result of the method FillingCurve3D.hash2ijk(long)

Returns:

the discretized horizontal coordinate stored in the given parameter ijk

ijk2k

public int ijk2k(long ijk)

Description copied from interface: FillingCurve3D

Extract the discretized depth coordinates from the result of the method FillingCurve3D.hash2ijk(long).

Specified by:

ijk2k in interface FillingCurve3D

Parameters:

ijk - result of the method FillingCurve3D.hash2ijk(long)

Returns:

the discretized horizontal coordinate stored in the given parameter ijk