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...Switch to Plot a Different Celestial Coordinate Grid  

Once you have set up a Plot to draw a coordinate grid ([*]), it is a simple matter to change things so that the grid represents a different celestial coordinate system. For example, after creating the Plot with astPlot, you could use:

astSet( plot, "System=Galactic" );
or:
astSet( plot, "System=FK5, Equinox=J2010" );

and any axes and/or grid drawn subsequently would represent the new celestial coordinate system you specified. Note, however, that this will only work if the original grid represented celestial coordinates of some kind (see [*] for how to determine if this is the case[*]). If it did not, you will get an error message.

For more information about the celestial coordinate systems available, see the descriptions of the System, Equinox and Epoch attributes in [*].



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AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
30th April 2003
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2003 Central Laboratory of the Research Councils