Package uk.ac.starlink.ttools.plot2.data

Class SkyCoord

  • All Implemented Interfaces:
    Coord
    public abstract class SkyCoord
extends java.lang.Object
implements Coord
    Coord implementation for sky positions. To the user these look like (longitude, latitude) pairs, but they are stored as (x,y,z) triples. This class exists in two variants: for surface the vectors are normalised to a magnitude of 1, so that they all fall on the centre of the unit sphere. For volume, that constraint does not apply.
    Since:
    4 Feb 2013
    Author:
    Mark Taylor

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  SkyCoord.SkyVariant
      Controls the interpretation of sky vectors, either fixed to the surface of the unit sphere or not.

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static SkyCoord createCoord​(SkyCoord.SkyVariant variant, boolean isRequired)
      Factory method to create an instance of this class.
      static InputMeta createRadiusInputMeta()
      Returns an InputMeta for acquiring a radial distance.
      Input[] getInputs()
      Returns specifications of the one or more input values the user supplies to provide the data values for this coord.
      StorageType getStorageType()
      Returns a code indicating how the quantity defined by this object is stored internally and presented to the plotting classes.
      boolean isRequired()
      Indicates whether this item must have a non-blank value in order for a plot to be possible.
      static double[] lonLatDegreesToDouble3​(double lonDeg, double latDeg)
      Converts a longitude, latitude pair into a normalised 3-vector.
      abstract boolean readSkyCoord​(Tuple tuple, int icol, double[] v3)
      Reads a sky vector value from an appropriate column in the current row of a given Tuple.

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • getInputs

        public Input[] getInputs()
        Description copied from interface: Coord
        Returns specifications of the one or more input values the user supplies to provide the data values for this coord.
        Specified by:
        getInputs in interface Coord
        Returns:
        one or more items describing the user input values for this quantity

      • getStorageType

        public StorageType getStorageType()
        Description copied from interface: Coord
        Returns a code indicating how the quantity defined by this object is stored internally and presented to the plotting classes.
        Specified by:
        getStorageType in interface Coord
        Returns:
        storage type enum instance

      • isRequired

        public boolean isRequired()
        Description copied from interface: Coord
        Indicates whether this item must have a non-blank value in order for a plot to be possible.
        Specified by:
        isRequired in interface Coord
        Returns:
        if true, values must be supplied to make a plot

      • readSkyCoord

        public abstract boolean readSkyCoord​(Tuple tuple,
                                     int icol,
                                     double[] v3)
        Reads a sky vector value from an appropriate column in the current row of a given Tuple.
        Parameters:
        tuple - tuple
        icol - index of field in tuple corresponding to this Coord
        v3 - 3-element vector into which the (x,y,z) sky position will be written
        Returns:
        true iff a valid position has been successfully read

      • createCoord

        public static SkyCoord createCoord​(SkyCoord.SkyVariant variant,
                                   boolean isRequired)
        Factory method to create an instance of this class.
        Parameters:
        variant - type of sky coordinates
        isRequired - true if this coordinate is required for plotting

      • lonLatDegreesToDouble3

        public static double[] lonLatDegreesToDouble3​(double lonDeg,
                                              double latDeg)
        Converts a longitude, latitude pair into a normalised 3-vector. If the input values are out of range, the components of the returned vector will all be NaN.
        Parameters:
        lonDeg - longitude in degrees
        latDeg - latitude in degrees
        Returns:
        (x,y,z) array of components of a normalised vector

      • createRadiusInputMeta

        public static InputMeta createRadiusInputMeta()
        Returns an InputMeta for acquiring a radial distance.
        Returns:
        new radial distance input metadata object