Function rotate_position 

pub fn rotate_position(
    a: &Vector3d,
    pole: &Vector3d,
    angle: Angle,
    radius: Angle,
) -> Vector3d

Calculate the position of a point rotated by angle at radius.

• a - the start point.
• pole - the pole of a Great Circle.
• angle - the angle to rotate the direction vector by.
• radius - the radius from the start point.

returns the position vector at angle and radius from the start point.