Roy says:
> OK I am showing my ignorance of what magnitude exactly means. But
> it sounds like you are taking a hard line that the concept of
> "magnitude" is meaningless by itself, and has no place in the UCD
> list. Surely it has some rigorous definition in terms of photons or
> flux or energy or SOMETHING? And therefore a context in which they
> can be compared.
No, magnitudes are fine - precisely because they have a fuzzy definition. What I was apparently arguing only poorly was that more interesting things like photon counting are harder to represent using simple scalar quantities/names or lists (even hierarchical lists) of same.
> And what is wrong with world coordinates? We have UCDs for CRVAL
> and CRPIX and CTYPE and all those good WCS keywords. Are they also
> so poorly defined as to be useless? They are well-defined in the
> Calabretta papers, aren't they?
I'm situated in a rather awkward location in the Moscone Center and the wifi keeps cutting out, so I won't try to reply in detail, but surely it would be better to provide a single identifier to a complete WCS data structure than to label each separate piece of same? But fundamentally I was just attempting so add a "me, too" to Steve's much more cogently worded reply. If he isn't panicking - neither am I.
> The namespaces for UCD was my suggestion. I was voted down.
Maybe it's time to have another vote.
Rob Received on 2005-06-29Z19:52:41