EFRAMES = VL_FRAME2OELL(FRAMES) converts the specified FRAMES to the oriented ellipses EFRAMES.
A frame is either a point, disc, oriented disc, ellipse, or oriented ellipse. These are represened respecively by 2, 3, 4, 5 and 6 parameters each, as described in VL_PLOTFRAME().
An oriented ellipse is the most general frame. When an unoriented frame is converted to an oriented ellipse, the rotation is selected so that the positive Y direction is unchanged.
See: VL_PLOTFRAME(), VL_HELP().