<div dir="ltr">Agreed<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr">-------------------------------------------------------------------------------------------------------------<br>Arnold H. Rots Chandra X-ray Science Center<br>Smithsonian Astrophysical Observatory tel: +1 617 496 7701<br>60 Garden Street, MS 67 fax: +1 617 495 7356<br>Cambridge, MA 02138 <a href="mailto:arots@cfa.harvard.edu" target="_blank">arots@cfa.harvard.edu</a><br>USA <a href="http://hea-www.harvard.edu/~arots/" target="_blank">http://hea-www.harvard.edu/~arots/</a><br>--------------------------------------------------------------------------------------------------------------<br><br></div></div></div>
<br><div class="gmail_quote">On Wed, Jul 15, 2015 at 6:53 AM, Alberto Micol <span dir="ltr"><<a href="mailto:amicol.ivoa@googlemail.com" target="_blank">amicol.ivoa@googlemail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Hi Doug, All,<br>
<br>
If an axis is not sampled, then its dimension (in the sense of s_dim, t_dim etc)<br>
is to be set to 1 given that any observation takes place in at least 1 point in space<br>
in at least 1 point in time, etc.<br>
<br>
Therefore I object to the idea of setting to 0 the spatial or spectral dim<br>
in the event list case.<br>
<br>
My 2 cents,<br>
Alberto<br>
<div class="HOEnZb"><div class="h5"><br>
<br>
><br>
> Le 25/06/2015 03:06, Douglas Tody a écrit :<br>
>> On Wed, 24 Jun 2015, CresitelloDittmar, Mark wrote:<br>
>>> pg 25: Axes dimensions<br>
>>> Outside of the pixelated image context, what values do these hold?<br>
>>> For example, the sparse cube (ie: event list). do each of these hold<br>
>>> the #events? or are s_dim1,s_dim2 == the span along that axis? and<br>
>>> if so, in what frame?<br>
>>> It seems that #events is closest to the description as the number of<br>
>>> samples.<br>
>><br>
>> For event data which is not imaged, such as an event list, probably the<br>
>> best one can do is have t_dim specify the number of events. The spatial<br>
>> coverage would be specified with s_fov and the spectral coverage with<br>
>> em_min/max. The binning on the spatial and spectral axes is meaningless<br>
>> and should be zero. If a precomputed image for the observation is also<br>
>> provided, that would have all the dim values and would share the same<br>
>> obs_id.<br>
>><br>
>> - Doug<br>
><br>
> --<br>
> ---- Laurent MICHEL Tel (33 0) 3 68 85 24 37<br>
> Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32<br>
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> ---<br>
<br>
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