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Using a Plot as a Frame

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 astDistance and astOffset functions will compute distances and offsets in physical coordinate space, while astFormat and astNorm will format physical coordinates in an appropriate way for display.


next up previous 264
Next: Regions of Valid Physical Coordinates
Up: Producing Graphical Output (Plots)
Previous: Using a Plot as a Mapping

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council