skyview.geometry
Class Util

java.lang.Object
  skyview.geometry.Util

public final class Util
extends java.lang.Object

Method Summary

static double[]	coord(double[] unit) Convert a unit vector to the corresponding coordinates.
static void	coord(double[] unit, double[] coord) Convert a unit vector to the corresponding coordinates.
static double	sphdist(double lon1, double lat1, double lon2, double lat2) Distance between two points on a unit sphere.
static double	sphdistDeg(double lon1, double lat1, double lon2, double lat2) Distance between two points on a unit sphere with angles in degres.
static double[]	unit(double[] coord) Convert a coordinate pair to unit vectors
static void	unit(double[] coord, double[] unitV) Convert a coordinate pair to unit vectors.
static double[]	unit(double ra, double dec) Convert a coordinate pair to unit vectors

Methods inherited from class java.lang.Object

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

Method Detail

unit

public static double[] unit(double ra,
                            double dec)

Convert a coordinate pair to unit vectors

Parameters:

ra - The longitude like coordinate in radians.

dec - The latitude like coordinate in radians.

Returns:

A double[3] unit vector corresponding to the coordinates.

unit

public static double[] unit(double[] coord)

Convert a coordinate pair to unit vectors

Parameters:

coord - The input coordinates

Returns:

A double[3] unit vector corresponding to the coordinates.

unit

public static void unit(double[] coord,
                        double[] unitV)

Convert a coordinate pair to unit vectors. The user supplies the array to be filled, assumed to be a vector of length 3. are created in this version.

Parameters:

coord - A double[2] vector of coordinates.

unitV - A pre-allocated double[3] unit vector. The values of this vector will be changed on output.

coord

public static double[] coord(double[] unit)

Convert a unit vector to the corresponding coordinates.

Parameters:

unit - A double[3] unit vector.

Returns:

A double[2] coordinate vector.

coord

public static void coord(double[] unit,
                         double[] coord)

Convert a unit vector to the corresponding coordinates.

Parameters:

unit - A double[3] unit vector.

coord - A double[2] vector to hold the output coordinates.

sphdist

public static double sphdist(double lon1,
                             double lat1,
                             double lon2,
                             double lat2)

Distance between two points on a unit sphere.

sphdistDeg

public static double sphdistDeg(double lon1,
                                double lat1,
                                double lon2,
                                double lat2)

Distance between two points on a unit sphere with angles in degres.