[fitsbits] Packed binary values

[Steve Allen]

On Mon 2007-04-30T12:37:54 -0400, William Pence hath writ:
> Mike Nolan a ecrit :
> > At moderate data rates, the header information changes slowly compared
> > to the spectral dump rate, and the time axis may become nondegenerate
> > within a record.

> One could write the packed data to a bit column in the binary  table
> with TFORMn = 'rX'. The TDIMn keyword could be used to convey the number
> of bits per sample.  For example, a 1-dimensional 256-sample  spectrum
> with 2 bits per sample could be stored with
>
> TFORMn = '512X'
> TDIMn  = '(2,256)'
>
> This could be extended to higher dimensional data.  If the record
> contained the spectrum that was read out a 4 successive times, then it
> could be stored with

I'm pretty sure that a binary table like this will also allow
the WCS conventions to describe a non-degenerate temporal axis.

With the usual caveats about the explicit ambiguity, it should be
straightforward to use the methods of WCS Papers II & III to describe
more coordinate axes than there are recorded in the table column.

--
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