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SortBy - Determines how keys are sorted in a KeyMap

Description:
This attribute determines the order in which keys are returned by the AST_MAPKEY function. It may take the following values (the default is "None"):

  • "None": The keys are returned in an arbitrary order. This is the fastest method as it avoids the need for a sorted list of keys to be maintained and used.

  • "AgeDown": The keys are returned in the order in which they were stored in the KeyMap, with the most recent key being returned last.

  • "AgeUp": The keys are returned in the order in which they were stored in the KeyMap, with the most recent key being returned first.

  • "KeyDown": The keys are returned in alphabetical order, with "A..." being returned last.

  • "KeyUp": The keys are returned in alphabetical order, with "A..." being returned first.
Type:
String.
Class Applicability:
KeyMap
All KeyMaps have this attribute.
Notes:
  • If a new value is assigned to SortBy (or if SortBy is cleared), all entries currently in the KeyMap are re-sorted according to the new SortBy value.


next up previous 264
Next: SourceSys - Spectral system in which the source velocity is stored
Up: AST Attribute Descriptions
Previous: SkyRefP(axis) - Position on primary meridian of offset coordinate system

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council