Package uk.ac.starlink.ttools.plot2.geom

Class Rotation

  • @Equality
public abstract class Rotation
extends java.lang.Object
    Rotates vectors between sky systems.
    Since:
    20 Apr 2016
    Author:
    Mark Taylor

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static Rotation IDENTITY
      Identity rotation; the rotate method is a no-op.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected Rotation()
      Protected no-arg constructor of abstract class.

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static Rotation createRotation​(SkySys inSys, SkySys outSys)
      Returns a rotation instance that can transform between two submitted sky systems.
      abstract double[] getMatrix()
      Returns the 9-element matrix defining this rotation.
      abstract Rotation invert()
      Returns the inverse of this rotation.
      static boolean isIdentityRotation​(SkySys inSys, SkySys outSys)
      Indicates whether the rotation between two sky systems is known to be an identity (no-op) transformation.
      abstract void rotate​(double[] r3)
      Rotates a 3-vector in place.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • IDENTITY

        public static Rotation IDENTITY
        Identity rotation; the rotate method is a no-op.

    • Constructor Detail

      • Rotation

        protected Rotation()
        Protected no-arg constructor of abstract class.

    • Method Detail

      • rotate

        public abstract void rotate​(double[] r3)
        Rotates a 3-vector in place.
        Parameters:
        r3 - 3-element unit vector, changed on output

      • invert

        public abstract Rotation invert()
        Returns the inverse of this rotation.
        Returns:
        inverse rotation

      • getMatrix

        public abstract double[] getMatrix()
        Returns the 9-element matrix defining this rotation.
        Returns:
        9-element rotation matrix

      • isIdentityRotation

        public static boolean isIdentityRotation​(SkySys inSys,
                                         SkySys outSys)
        Indicates whether the rotation between two sky systems is known to be an identity (no-op) transformation. If either or both sky systems is null, it is assumed that no rotation is required.
        Parameters:
        inSys - input sky system; may be null
        outSys - output sky system; may be null
        Returns:
        true iff no rotation operation is required

      • createRotation

        public static Rotation createRotation​(SkySys inSys,
                                      SkySys outSys)
        Returns a rotation instance that can transform between two submitted sky systems.
        Parameters:
        inSys - input sky system; may be null
        outSys - output sky system; may be null
        Returns:
        rotation from input to output sky systems, not null