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MaxAxes - Maximum number of Frame axes to match   

Description:
This attribute controls how a Frame behaves when it is used (by astFindFrame) as a template to match another (target) Frame. It specifies the maximum number of axes that the target Frame may have in order to match the template.

Normally, this value will equal the number of Frame axes, so that a template Frame will only match another Frame with the same number of axes as itself. By setting a different value, however, the matching process may be used to identify Frames with specified numbers of axes.

Type:
Integer.

Class Applicability:
Frame
The default MaxAxes value for a Frame is equal to the number of Frame axes (Naxes attribute).
SkyFrame
The SkyFrame class constrains the MaxAxes value to be 2. Any attempt to alter this value is simply ignored.
CmpFrame
The MaxAxes attribute of a CmpFrame is equal to the sum of the MaxAxes values of its two component Frames. Any attempt to alter this value (other than through the component Frames) is simply ignored.
FrameSet
The MaxAxes attribute of a FrameSet is the same as that of its current Frame (as specified by the Current attribute).

Notes:
  • When setting a MaxAxes value, the value of the MinAxes attribute may also be silently changed so that it remains consistent with (i.e. does not exceed) the new value. The default MaxAxes value may also be reduced to remain consistent with the MinAxes value.
  • If a template Frame is used to match a target with a different number of axes, the MatchEnd attribute of the template is used to determine how the individual axes of each Frame should match.



next up previous
Next: MinAxes - Minimum number of Frame axes to match
Up: AST Attribute Descriptions
Previous: MatchEnd - Match trailing axes?

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