Class PixtoolsHealpixSkyPixellator

  • All Implemented Interfaces:
    SkyPixellator

    public class PixtoolsHealpixSkyPixellator
    extends HealpixSkyPixellator
    HEALPix sky pixellator using the PixTools library. This implementation is based on the PixTools Java HEALPix classes written by Nickolai Kouropatkine at Fermilab. The maximum K value is 20.
    Author:
    Mark Taylor (Starlink), Nickolai Kouropatkine (EAG, Fermilab)
    See Also:
    http://home.fnal.gov/~kuropat/HEALPIX/PixTools.html
    • Constructor Detail

      • PixtoolsHealpixSkyPixellator

        public PixtoolsHealpixSkyPixellator​(boolean nested)
        Constructs a pixellator using either the RING or NESTED HEALPix scheme.
        Parameters:
        nested - false for RING scheme, true for NESTED
      • PixtoolsHealpixSkyPixellator

        public PixtoolsHealpixSkyPixellator()
        Constructs a pixellator using the default scheme (RING).
    • Method Detail

      • getPixels

        public java.lang.Object[] getPixels​(double alpha,
                                            double delta,
                                            double radius)
        Description copied from interface: SkyPixellator
        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
      • configureK

        protected void configureK​(int k)
        Description copied from class: HealpixSkyPixellator
        Updates internal state for the current value of the k parameter.
        Specified by:
        configureK in class HealpixSkyPixellator
        Parameters:
        k - HEALPix order
      • calculateDefaultK

        public int calculateDefaultK​(double scale)
        Determines a default value to use for the HEALPix k parameter based on a given scale.
        Specified by:
        calculateDefaultK in class HealpixSkyPixellator
        Parameters:
        scale - distance scale, in radians