Every Plot is also a Frame, so can be used to obtain the values of
Frame attributes such as a Title, axis Labels, axis Units,
etc., which are typically used when displaying data and/or
coordinates. These attributes are, as for any FrameSet, derived from
the current Frame of the Plot (). They are
also used automatically when using the Plot to plot coordinate axes
and coordinate grids (e.g. for labelling
them--
).
Because the current Frame of a Plot represents physical coordinates, any Frame operation applied to the Plot will effectively be working in this coordinate system. For example, the AST_DISTANCE and AST_OFFSET routines will compute distances and offsets in physical coordinate space, and AST_FORMAT will format physical coordinates in an appropriate way for display.
AST A Library for Handling World Coordinate Systems in Astronomy