[fitsbits] CDELTn

[Mark Calabretta]

On Tue 2007/09/18 13:17:48 +0200, Francois Ochsenbein wrote
in a message to: fitsbits at nrao.edu
and copied to: pence at milkyway.gsfc.nasa.gov

>I just found a curiosity: FITS files having CDELTn axis set to zero.
>This may look strange, but when the corresponding NAXISn is 1, this 
>should be harmless. Is the value zero actually forbidden in the 

That's illegal for the good reason that NAXISn is not a WCS keyword -
i.e. NAXISn is irrelevant when constructing a coordinate description.
The data structures in WCSLIB do not even hold the NAXISn values.

Mark Calabretta