SkyPixellator (Starjava Table API)

All Known Implementing Classes:

HealpixSkyPixellator, HtmSkyPixellator, PixtoolsHealpixSkyPixellator
```
public interface SkyPixellator
```
Provides a pixellisation of the celestial sphere. Usually it is necessary to call setScale(double) before an instance of this class can be used.

Since:

5 Sep 2011

Author:

Mark Taylor

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`java.lang.Object[]`	`getPixels(double alpha, double delta, double radius)` Returns an array of objects representing pixels in a given region.
`double`	`getScale()` Returns the most recently set angular scale.
`DescribedValue`	`getTuningParameter()` Returns a parameter whose value may be adjusted to alter the pixellisation scale.
`void`	`setScale(double scale)` Sets the characteristic angular scale for this pixellator.

- Method Detail
  - setScale
```
void setScale(double scale)
```
    Sets the characteristic angular scale for this pixellator. Pixels should be approximately the size given, so that a larger scale corresponds to larger pixel sizes. The details of pixel size are determined by the details of the pixellation scheme however.
    
    Parameters:
    
    scale - pixel length scale in radians
  - getScale
```
double getScale()
```
    Returns the most recently set angular scale.
    
    Returns:
    
    pixel length scale in radians
  - getPixels
```
java.lang.Object[] getPixels(double alpha,
                             double delta,
                             double radius)
```
    Returns an array of objects representing pixels in a given region. The parameters specify a small circle on the sphere; any pixels which overlap this circle must be returned (additional pixels may also be returned). The output objects are of some opaque type, but must implement the equals and hashCode methods appropriately, so that objects returned from one call can be compared for identity with objects returned from a subsequent call. This comparability is only guaranteed to work if the pixel scale is not changed in between calls.
    
    Parameters:
    
    alpha - right ascension of circle centre in radians
    
    delta - declination of circle centre in radians
    
    radius - radius of circle in radians
    
    Returns:
    
    array of opaque but comparable pixel objects
  - getTuningParameter
```
DescribedValue getTuningParameter()
```
    Returns a parameter whose value may be adjusted to alter the pixellisation scale. This is not necessarily the same as the scale attribute (its value need not be an angle).
    
    Returns:
    
    tuning parameter

Interface SkyPixellator

Method Summary

Method Detail

setScale

getScale

getPixels

getTuningParameter