<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div>Hello Pat,</div><div><br></div><div><br></div><div><blockquote type="cite"><div>On 10 Nov 2024, at 23:55, Patrick Dowler via semantics <semantics@ivoa.net> wrote:</div><br class="Apple-interchange-newline"><div><div dir="ltr"><div><br></div><div><div style="font-size:small" class="gmail_default">Yes, I have been thinking about it and have similar questions with regards to CAOM and <br></div><div style="font-size:small" class="gmail_default">vocabularies it uses/refers to.</div></div></div></div></blockquote><div><br></div>We are maybe in a good time slot for introducing vocabs in DMs.</div><div>For the record, I’ll start to exercise this with the calibration levels.</div><div><br><blockquote type="cite"><div><div dir="ltr"><div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">For DALI xtypes in particular, I think it is in scope for some DM discussions this week whether </div><div style="font-size:small" class="gmail_default">and how to define those data types in the base ivoa data model (which has some things already</div><div style="font-size:small" class="gmail_default">that are not purely primitive types). It is technically doable in VO-DML and then would be <br></div><div style="font-size:small" class="gmail_default">easily imported and used consistently across various data models. I think this makes sense and</div><div style="font-size:small" class="gmail_default">fits my view that xtypes are not really a vocabulary <br></div></div></div></div></blockquote><div><br></div>Yes, technically there no problem with using vocabularies to specify allowed values for particular model attributes.</div><div>However, this requires the vocabulary to have a hierarchy setup in order to prevent mixing words related to different domains such as region vs sky coordinates, which is not the case today with Xtypes.</div><div>In my understanding, <span style="font-size: small;">xtypes are not really a vocabulary in a sense that DALI defines them as a flat list of words.</span></div><div><span style="font-size: small;">If we use them in MANGO, we must first transform this list into a real vocabulary with a concept hierarchy.</span></div><div><br><blockquote type="cite"><div><div dir="ltr"><div><div style="font-size:small" class="gmail_default">The question for MANGO would be: if all those data types were in the ivoa base model and DALI </div><div style="font-size:small" class="gmail_default">was specifying the serialization of a single value, how would that change/work in MANGO?<br></div></div></div></div></blockquote><div><br></div>If we can issue a vocabulary from the xtype definitions, there will be no major change for MANGO.</div><div>The question is ot know whether if worth it to build that vocabulary or not.</div><div><br></div><div>Laurent<br><blockquote type="cite"><div><div dir="ltr"><div><div style="font-size:small" class="gmail_default"></div><br></div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div>--<br></div><div>Patrick Dowler<br></div>Canadian Astronomy Data Centre<br></div>Victoria, BC, Canada<br></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 8 Nov 2024 at 09:29, Markus Demleitner via semantics <<a href="mailto:semantics@ivoa.net">semantics@ivoa.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Laurent,<br>
<br>
On Fri, Nov 08, 2024 at 04:43:43PM +0100, Laurent Michel via semantics wrote:<br>
> I totally agree with you.<br>
> Xtypes provide some words that must be reused in MANGO.<br>
> The problem is to find a convenient way to connect both worlds.<br>
> Xtype definitions are sparse in the VO documentation and there is no hierarchy ordering them:<br>
> - "xtype=hms" is at the same level as "xtype=moc"<br>
><br>
> The connection with MANGO could be done just through the attribute definition:<br>
> - the value of this attribute must match one of (A,B,C) which<br>
> are Xtype allowed values as defined in XYZ<br>
><br>
> Or dare I suggest another option which is to put Xtype values in a<br>
> specific vocabulary (xtype.rdf)?<br>
<br>
I think the idea of having a machine-readable list of xtypes as a<br>
vocabulary has come up before, although I couldn't say where. I<br>
could see some applications beyond MANGO, in particular when we<br>
consider re-opening xtypes beyond DALI. Hm.<br>
<br>
Pat, are you reading this?<br>
<br>
-- Markus<br>
<br>
</blockquote></div>
</div></blockquote></div><br></body></html>