[Obscore1.1] WD comments

[Arnold Rots]

This may get complicated.
In principle, I agree, but some axes may actually be binned, such as chip
coordinates and pulse height...

  - Arnold

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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 Mon, Jul 13, 2015 at 8:45 AM, Laurent MICHEL <
laurent.michel at astro.unistra.fr> wrote:

> Hello,
>
> I do not think that t_dim is better suited than e_dim or s_dim to specify
> the number of events. Finally, an event is just a point within a 4dims
> space (S1/S2/E/T) and none of these axes has a special role.
> Considering that, I think the number of events should be reported in all
> *_dim columns. The ambiguity about binned axes or not is removed by the
> appropriate "dataproduct_type" value.
>
> Laurent
>
>
> 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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