HealpixTiling (Starjava TTOOLS API)

java.lang.Object
- uk.ac.starlink.ttools.cone.HealpixTiling

All Implemented Interfaces:

SkyTiling
```
public class HealpixTiling
extends java.lang.Object
implements SkyTiling
```
Tiling implementation based on the HEALPix scheme.

Since:

12 Dec 2007

Author:

Mark Taylor

Constructor Summary

Constructors
Constructor Description

HealpixTiling(int k, boolean nest)
Constructor.

Constructors
Constructor	Description
`HealpixTiling(int k, boolean nest)`	Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`uk.ac.starlink.table.ValueInfo`	`getIndexInfo()`	Returns a metadata item suitable for describing the pixel index used by this tiling.
`long`	`getPixelCount()`	Returns the total number of tiles in this tiling.
`long`	`getPositionTile(double ra, double dec)`	Returns the index of the tile in which a given sky position falls.
`long[]`	`getTileRange(double ra, double dec, double radius)`	Returns the bounds of a range of pixels which is known to cover a given cone on the sky.

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

- Constructor Detail
  - HealpixTiling
```
public HealpixTiling(int k,
                     boolean nest)
```
    Constructor.
    
    Parameters:
    
    k - log to base 2 of HEALPix Nside parameter
    
    nest - true for nesting scheme, false for ring scheme
- Method Detail
  - getPixelCount
```
public long getPixelCount()
```
    Description copied from interface: SkyTiling
    
    Returns the total number of tiles in this tiling. Tile indices are assumed to be in the range from zero (inclusive) to this value (exclusive), so the returned value is one greater than the maximum tile index.
    
    Specified by:
    
    getPixelCount in interface SkyTiling
    
    Returns:
    
    pixel count
  - getIndexInfo
```
public uk.ac.starlink.table.ValueInfo getIndexInfo()
```
    Description copied from interface: SkyTiling
    
    Returns a metadata item suitable for describing the pixel index used by this tiling.
    
    Specified by:
    
    getIndexInfo in interface SkyTiling
    
    Returns:
    
    tile index metadata
  - getPositionTile
```
public long getPositionTile(double ra,
                            double dec)
```
    Description copied from interface: SkyTiling
    
    Returns the index of the tile in which a given sky position falls.
    
    Specified by:
    
    getPositionTile in interface SkyTiling
    
    Parameters:
    
    ra - right ascension in degrees
    
    dec - declination in degrees
    
    Returns:
    
    tile index for position
  - getTileRange
```
public long[] getTileRange(double ra,
                           double dec,
                           double radius)
```
    Description copied from interface: SkyTiling
    
    Returns the bounds of a range of pixels which is known to cover a given cone on the sky. The return value is a two-element array, (lo,hi). Every point in the specified cone must have a tile index which is greater than or equal to the first element of that array, and less than or equal to the second element. If the question cannot be answered, or if the range is thought to be too large to be of use (for instance, if it would take a long time to calculate), then null may be returned.
    
    Specified by:
    
    getTileRange in interface SkyTiling
    
    Parameters:
    
    ra - right ascension in degrees
    
    dec - declination in degrees
    
    radius - radius in degrees
    
    Returns:
    
    2-element array giving inclusive (low, high) bounds of tile range covering the cone

Class HealpixTiling

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

HealpixTiling

Method Detail

getPixelCount

getIndexInfo

getPositionTile

getTileRange