[fitswcs] Complex values in FITS {External}

[Patrick Leahy]

Hi Folks,
                Not sure if this is the right list, but there is currently a discussion going on about the right way to store Faraday synthesis spectra and spectral cubes, which are complex-valued. One way is to use a COMPLEX axis as discussed in WCS paper I (and the original FITS papers).  But there seems to be a long-standing inconsistency in the FITS standard on this point. All references agree that COMPLEX value 1 is real and 2 is complex. But the example of this in the standard, Table 28, is:

SIMPLE=T

BITPIX=32

NAXIS=2

NAXIS1=2

NAXIS2=100

CTYPE1='COMPLEX'

CRVAL1=0.

CRPIX1=0.

CDELT1=1.

END


Here the complex axis runs from 0 to 1, not 1 to 2 as expected. Is this a mistake or am I misreading?

Regards,
                                Paddy Leahy
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