Interface HealpixMask

All Known Implementing Classes:
BitsetMask

public interface HealpixMask
Represents an area on the sky using HEALPix tesselation. On construction, the area is empty.

This interface defines what is required for use by the SkyCoverage class. The defined behaviour is somewhat like a MOC, and can be implemented using a MOC, but standard MOC implementations may not have suitable performance characteristics; in particular the addPixel(int, long) method ought to be fast.

Since:
8 Jun 2022
Author:
Mark Taylor
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    Defines a way to test inclusion of HEALPix pixels in an area.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addPixel(int order, long ipix)
    Adds the area corresponding to a HEALPix pixel to this mask.
    Returns an object that can test inclusion in the sky area defined by the current state of this mask.
    double
    Returns the fraction of the sky currently covered by this mask.
    void
    Narrows this area to represent the intersection of this mask and another compatible mask.
    boolean
    Returns true if this mask's area is empty.
    void
    Extends this area to represent the union of this mask and another compatible mask.
  • Method Details

    • isEmpty

      boolean isEmpty()
      Returns true if this mask's area is empty.
      Returns:
      true iff the createPixelTester() test is guaranteed to return false
    • intersection

      void intersection(HealpixMask other)
      Narrows this area to represent the intersection of this mask and another compatible mask.
      Parameters:
      other - different mask of a type assumed compatible with this one
    • union

      void union(HealpixMask other)
      Extends this area to represent the union of this mask and another compatible mask.
      Parameters:
      other - different mask of a type assumed compatible with this one
    • getSkyFraction

      double getSkyFraction()
      Returns the fraction of the sky currently covered by this mask.
      Returns:
      sky fraction between 0 and 1
    • addPixel

      void addPixel(int order, long ipix)
      Adds the area corresponding to a HEALPix pixel to this mask.
      Parameters:
      order - HEALPix order
      ipix - HEALPix pixel index at order order
    • createPixelTester

      HealpixMask.PixelTester createPixelTester()
      Returns an object that can test inclusion in the sky area defined by the current state of this mask.
      Returns:
      thread-safe test for sky area inclusion