Package talonsoalbi_at_gmail_dot_com.ssoxmatch.ephem

Class LocationElement

java.lang.Object
talonsoalbi_at_gmail_dot_com.ssoxmatch.ephem.LocationElement
All Implemented Interfaces:
Serializable
public class LocationElement extends Object implements Serializable
This is a convenience class used for passing around spherical coordinates. Units are radians for longitude and latitude, AU for distance.
Author:
talonso
See Also:

  • Constructor Details

    • LocationElement

      public LocationElement()
      Default constructor.

    • LocationElement

      public LocationElement(double lon, double lat, double rad)
      Explicit constructor.
      Parameters:
      lon - longitude.
      lat - latitude.
      rad - radius.

    • LocationElement

      public LocationElement(double[] vector)
      Vector constructor.
      Parameters:
      vector - { lon, lat, rad }

  • Method Details

    • getLatitude

      public double getLatitude()
      Gets the latitude.
      Returns:
      The latitude value of this instance.

    • getLongitude

      public double getLongitude()
      Gets the longitude.
      Returns:
      The longitude value of this instance.

    • getRadius

      public double getRadius()
      Gets the radius.
      Returns:
      The radius value of this instance.

    • get

      public double[] get()
      Get all values in this instance as a vector.

      The vector is an array of three doubles, longitude, latitude, radius.

      Returns:
      v[0] = longitude, v[1] = latitude, v[2] = radius.

    • setRadius

      public void setRadius(double d)
      Set the radius.
      Parameters:
      d - The new radius value.

    • set

      public void set(double[] vector)
      Set all members of this instance from a vector.

      The vector is an array of three doubles, longitude, latitude, radius, in that order.

      Parameters:
      vector - v[0] = longitude, v[1] = latitude, v[2] = radius.

    • set

      public void set(double lon, double lat, double rad)
      Set all members of this instance individually.
      Parameters:
      lon - The new longitude.
      lat - The new latitude.
      rad - The new radius.

    • parseRectangularCoordinates

      public static LocationElement parseRectangularCoordinates(double[] v)
      Transforms rectangular coordinates x, y, z contained in an array to a LocationElement. Coordinate system is independent: equatorial, ecliptic, or any other.
      Parameters:
      v - (x, y, z) vector.
      Returns:
      Location object.

    • parseRectangularCoordinatesFast

      public static LocationElement parseRectangularCoordinatesFast(double[] v)
      Transforms rectangular coordinates x, y, z contained in an array to a LocationElement. Coordinate system is independent: equatorial, ecliptic, or any other. This method uses FastMath.atan2(double, double) and FastMath.asin(double) methods.
      Parameters:
      v - (x, y, z) vector.
      Returns:
      Location object.

    • parseRectangularCoordinatesFast

      public static LocationElement parseRectangularCoordinatesFast(double x, double y, double z)
      Transforms rectangular coordinates x, y, z contained in an array to a LocationElement. Coordinate system is independent: equatorial, ecliptic, or any other. This method calls parseRectangularCoordinatesFast(double[]).
      Parameters:
      x - X coordinate.
      y - Y coordinate.
      z - Z coordinate.
      Returns:
      Location object.

    • parseRectangularCoordinates

      public static LocationElement parseRectangularCoordinates(double x, double y, double z)
      Transforms rectangular coordinates x, y, z to a LocationElement. Coordinate system is independent: equatorial, ecliptic, or any other.
      Parameters:
      x - X coordinate.
      y - Y coordinate.
      z - Z coordinate.
      Returns:
      Location object.

    • parseLocationElement

      public static double[] parseLocationElement(LocationElement loc)
      Transforms a LocationElement into a set of rectangular coordinates x, y, z.
      Parameters:
      loc - Location object.
      Returns:
      Array with (x, y, z) vector.

    • parseLocationElementFast

      public static double[] parseLocationElementFast(LocationElement loc)
      Transforms a LocationElement into a set of rectangular coordinates x, y, z, using approximate trigonometric functions.
      Parameters:
      loc - Location object.
      Returns:
      Array with (x, y, z) vector.

    • getRectangularCoordinates

      public double[] getRectangularCoordinates()
      Transforms a LocationElement into a set of rectangular coordinates x, y, z.
      Returns:
      Array with (x, y, z) vector.

    • getLinearDistance

      public static double getLinearDistance(LocationElement loc1, LocationElement loc2)
      Obtain linear distance between two spherical positions.
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      Linear distance.

    • getMidPoint

      public static LocationElement getMidPoint(LocationElement loc1, LocationElement loc2)
      Obtain the direction between two spherical positions.
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      The midpoint.

    • solveSphericalTriangle

      public static double solveSphericalTriangle(LocationElement locA, LocationElement locP, LocationElement locP1, boolean approx)
      Solves an spherical triangle return the angle between the positions locP and locP1 as seen from locA.
      Parameters:
      locA - A position.
      locP - P position.
      locP1 - P1 position.
      approx - True for an approximate and faster computation.
      Returns:
      The spherical angle.

    • getAngularDistance

      public static double getAngularDistance(LocationElement loc1, LocationElement loc2)
      Obtain angular distance between two spherical coordinates.
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      The distance in radians, from 0 to PI.

    • getApproximateAngularDistance

      public static double getApproximateAngularDistance(LocationElement loc1, LocationElement loc2)
      Obtain approximate angular distance between two spherical coordinates. Almost exact result
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      The distance in radians, from 0 to PI.

    • getApproximatePositionAngle

      public static double getApproximatePositionAngle(LocationElement loc1, LocationElement loc2)
      Obtain position angle between two spherical coordinates. Good performance.
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      The position angle in radians.

    • getPositionAngle

      public static double getPositionAngle(LocationElement loc1, LocationElement loc2)
      Obtain exact position angle between two spherical coordinates. Performance will be poor.
      Parameters:
      loc1 - Location object.
      loc2 - Location object.
      Returns:
      The position angle in radians.

    • clone

      public LocationElement clone()
      To clone the object.

    • equals

      public boolean equals(Object o)
      Returns true if the input object is equals to this instance.
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Returns a String representation of this object.
      Overrides:
      toString in class Object

    • move

      public void move(double dlon, double dlat, double dr)
      Moves this position a given amount in each axis.
      Parameters:
      dlon - Displacement in longitude, radians. It is a pure incremental modification.
      dlat - Displacement in latitude, radians.
      dr - Displacemente in distance, in units of the distance.

    • toOffset

      public void toOffset(double dlon, double dlat)
      Moves this position a given amount in each axis, setting the location to a given point with some offset.
      Parameters:
      dlon - Displacement in longitude, radians. This increment is respect the sky plain, not a coordinate incremental offset.
      dlat - Displacement in latitude, radians.