Class SkyCoord

java.lang.Object
uk.ac.starlink.ttools.plot2.data.SkyCoord
All Implemented Interfaces:
Coord

public abstract class SkyCoord extends 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 
    Controls the interpretation of sky vectors, either fixed to the surface of the unit sphere or not.
  • Method Summary

    Modifier and Type
    Method
    Description
    static SkyCoord
    createCoord(SkyCoord.SkyVariant variant, boolean isRequired)
    Factory method to create an instance of this class.
    static InputMeta
    Returns an InputMeta for acquiring a radial distance.
    Returns specifications of the one or more input values the user supplies to provide the data values for this coord.
    Returns a code indicating how the quantity defined by this object is stored internally and presented to the plotting classes.
    boolean
    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

    Methods inherited from interface uk.ac.starlink.ttools.plot2.data.Coord

    inputStorage
  • Method Details

    • 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