[Obscore1.1] WD comments

[Arnold Rots]

Agreed

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Arnold H. Rots                                          Chandra X-ray
Science Center
Smithsonian Astrophysical Observatory                   tel:  +1 617 496
7701
60 Garden Street, MS 67                                      fax:  +1 617
495 7356
Cambridge, MA 02138
arots at cfa.harvard.edu
USA
http://hea-www.harvard.edu/~arots/
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On Wed, Jul 15, 2015 at 6:53 AM, Alberto Micol <amicol.ivoa at googlemail.com>
wrote:

>
> Hi Doug, All,
>
> If an axis is not sampled, then its dimension (in the sense of s_dim,
> t_dim etc)
> is to be set to 1 given that any observation takes place in at least 1
> point in space
> in at least 1 point in time, etc.
>
> Therefore I object to the idea of setting to 0 the spatial or spectral dim
> in the event list case.
>
> My 2 cents,
> Alberto
>
>
> >
> > Le 25/06/2015 03:06, Douglas Tody a écrit :
> >> On Wed, 24 Jun 2015, CresitelloDittmar, Mark wrote:
> >>> pg 25: Axes dimensions
> >>> Outside of the pixelated image context, what values do these hold?
> >>> For example, the sparse cube (ie: event list).  do each of these hold
> >>> the #events? or are s_dim1,s_dim2 ==  the span along that axis? and
> >>> if so, in what frame?
> >>> It seems that #events is closest to the description as the number of
> >>> samples.
> >>
> >> For event data which is not imaged, such as an event list, probably the
> >> best one can do is have t_dim specify the number of events.  The spatial
> >> coverage would be specified with s_fov and the spectral coverage with
> >> em_min/max.  The binning on the spatial and spectral axes is meaningless
> >> and should be zero.  If a precomputed image for the observation is also
> >> provided, that would have all the dim values and would share the same
> >> obs_id.
> >>
> >>     - Doug
> >
> > --
> > ---- Laurent MICHEL              Tel  (33 0) 3 68 85 24 37
> >     Observatoire de Strasbourg  Fax  (33 0) 3 68 85 24 32
> >     11 Rue de l'Universite      Mail laurent.michel at astro.unistra.fr
> >     67000 Strasbourg (France)   Web  http://astro.u-strasbg.fr/~michel
> > ---
>
>
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