SkyCoord (Starjava TTOOLS API)

java.lang.Object
- uk.ac.starlink.ttools.plot2.data.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.

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.
`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 interface uk.ac.starlink.ttools.plot2.data.Coord
inputToStorage

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

Class SkyCoord

Nested Class Summary

Method Summary

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

Methods inherited from class java.lang.Object

Method Detail

getInputs

getStorageType

isRequired

readSkyCoord

createCoord

lonLatDegreesToDouble3