Package 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

  • Constructor Details

    • 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 Details

    • 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