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When reading a FrameSet from a
FitsChan, WCS axis
in the current
Frame of the
resulting FrameSet corresponds to axis
in the FITS header.
When writing a FrameSet to a FitsChan, the axis ordering for the FITS
header is chosen to make the CDi_j or PCi_j matrix
predominately diagonal. This means that the axis numbering in the FITS
header will not necessarily be the same as that in the AST Frame.
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Up: Paper I - General Linear Coordinates
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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