uk.ac.starlink.table.join

Class SkyCoverage

java.lang.Object

uk.ac.starlink.table.join.SkyCoverage

All Implemented Interfaces:

Coverage

public abstract class SkyCoverage
extends Object
implements Coverage

Partial coverage implementation for use on the celestial sphere. It makes use of the HEALPix tesselation. Storage of HEALPix coverage information is handled by a supplied mask object.

Factory methods are provided for concrete instances of this class.

Since:

8 Jun 2022

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SkyCoverage.TupleDecoder Defines mapping a tuple to sky positional information.

Field Summary

Fields inherited from interface uk.ac.starlink.table.join.Coverage

FULL

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SkyCoverage() Constructor using an empty default healpix mask implementation.
protected	SkyCoverage(HealpixMask mask) Constructor using a custom healpix mask implementation.

Method Summary

Modifier and Type	Method and Description
String	coverageText() Provides a short, human-readable indication of the coverage.
static SkyCoverage	createFixedErrorCoverage(double errRad, SkyCoverage.TupleDecoder posDecoder) Creates a sky coverage suitable for a fixed match radius.
static SkyCoverage	createVariableErrorCoverage(double scaleRad, SkyCoverage.TupleDecoder coneDecoder) Creates a sky coverage suitable for a variable match radius.
HealpixMask	getMask() Returns the HEALPix mask implementation used by this object.
void	intersection(Coverage other) Narrows this coverage object to contain only the intersection of its current state and the supplied coverage.
boolean	isEmpty() Returns true if the coverage represents the empty set.
void	union(Coverage other) Modifies the state of this coverage object as if all the tuples fed to the other had been fed to this one as well as its current contents.

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.starlink.table.join.Coverage

createTestFactory, extend

Constructor Detail

SkyCoverage

protected SkyCoverage(HealpixMask mask)

Constructor using a custom healpix mask implementation.

Parameters:

mask - mask implementation

SkyCoverage

protected SkyCoverage()

Constructor using an empty default healpix mask implementation.

Method Detail

getMask

public HealpixMask getMask()

Returns the HEALPix mask implementation used by this object.

Returns:

mask

isEmpty

public boolean isEmpty()

Description copied from interface: Coverage

Returns true if the coverage represents the empty set.

Specified by:

isEmpty in interface Coverage

Returns:

true iff the Coverage.createTestFactory() test is guaranteed to return false

intersection

public void intersection(Coverage other)

Description copied from interface: Coverage

Narrows this coverage object to contain only the intersection of its current state and the supplied coverage.

Specified by:

intersection in interface Coverage

Parameters:

other - different coverage object of a type assumed compatible with this object

union

public void union(Coverage other)

Description copied from interface: Coverage

Modifies the state of this coverage object as if all the tuples fed to the other had been fed to this one as well as its current contents.

Specified by:

union in interface Coverage

Parameters:

other - different coverage object of a type assumed compatible with this object

coverageText

public String coverageText()

Description copied from interface: Coverage

Provides a short, human-readable indication of the coverage.

Specified by:

coverageText in interface Coverage

Returns:

string representation

createFixedErrorCoverage

public static SkyCoverage createFixedErrorCoverage(double errRad,
                                                   SkyCoverage.TupleDecoder posDecoder)

Creates a sky coverage suitable for a fixed match radius.

Parameters:

errRad - match error in radians

posDecoder - thread-safe converter from tuples to sky position; output is to (longitude, latitude) in radians

Returns:

new empty coverage

createVariableErrorCoverage

public static SkyCoverage createVariableErrorCoverage(double scaleRad,
                                                      SkyCoverage.TupleDecoder coneDecoder)

Creates a sky coverage suitable for a variable match radius.

Parameters:

scaleRad - characteristic scale of errors in radians (tuning parameter)

coneDecoder - thread-safe converter from tuples to sky region; output is to (longitude, latitude, radius) in radians

Returns:

new empty coverage