Class Ellipse

    • Constructor Detail

      • Ellipse

        public Ellipse​(Vector3D center,
                       Vector3D u,
                       Vector3D v,
                       double a,
                       double b,
                       Frame frame)
        Simple constructor.
        Parameters:
        center - center of the 2D ellipse
        u - unit vector along the major axis
        v - unit vector along the minor axis
        a - semi major axis
        b - semi minor axis
        frame - frame in which the ellipse is defined
    • Method Detail

      • getCenter

        public Vector3D getCenter()
        Get the center of the 2D ellipse.
        Returns:
        center of the 2D ellipse
      • getU

        public Vector3D getU()
        Get the unit vector along the major axis.
        Returns:
        unit vector along the major axis
      • getV

        public Vector3D getV()
        Get the unit vector along the minor axis.
        Returns:
        unit vector along the minor axis
      • getA

        public double getA()
        Get the semi major axis.
        Returns:
        semi major axis
      • getB

        public double getB()
        Get the semi minor axis.
        Returns:
        semi minor axis
      • getFrame

        public Frame getFrame()
        Get the defining frame.
        Returns:
        defining frame
      • pointAt

        public Vector3D pointAt​(double theta)
        Get a point of the 2D ellipse.
        Parameters:
        theta - angular parameter on the ellipse (really the eccentric anomaly)
        Returns:
        ellipse point at theta, in underlying ellipsoid frame
      • toSpace

        public Vector3D toSpace​(Vector2D p)
        Create a point from its ellipse-relative coordinates.
        Parameters:
        p - point defined with respect to ellipse
        Returns:
        point defined with respect to 3D frame
        See Also:
        toPlane(Vector3D)
      • toPlane

        public Vector2D toPlane​(Vector3D p)
        Project a point to the ellipse plane.
        Parameters:
        p - point defined with respect to 3D frame
        Returns:
        point defined with respect to ellipse
        See Also:
        toSpace(Vector2D)
      • projectToEllipse

        public Vector2D projectToEllipse​(Vector2D p)
        Find the closest ellipse point.
        Parameters:
        p - point in the ellipse plane to project on the ellipse itself
        Returns:
        closest point belonging to 2D meridian ellipse
      • projectToEllipse

        public TimeStampedPVCoordinates projectToEllipse​(TimeStampedPVCoordinates pv)
        Project position-velocity-acceleration on an ellipse.
        Parameters:
        pv - position-velocity-acceleration to project, in the reference frame
        Returns:
        projected position-velocity-acceleration
      • getCenterOfCurvature

        public Vector2D getCenterOfCurvature​(Vector2D point)
        Find the center of curvature (point on the evolute) at the nadir of a point.
        Parameters:
        point - point in the ellipse plane
        Returns:
        center of curvature of the ellipse directly at point nadir
        Since:
        7.1