Quantity "tables"
Ed Shaya
Edward.J.Shaya.1 at gsfc.nasa.gov
Fri Jan 23 08:06:52 PST 2004
Tony,
<Quantity type="Galactic_long" ..../> is the same concept as
<Galactic_long .../>, but the difference is,
the first one you can use as soon as we have a Quantity.xsd and before
it is extended for this particular concept. It is not mechanically
restricted to only have what we agree upon for Galactic_long.xsd.
Ed
Tony Linde wrote:
>Quick question, Ed: why is everything a <Quantity ... /> element? Why not a
><Galactic_long ... />, <Galactic_lat ... /> etc? Isn't it harder to use the
>metadata if you've got to work with types of Quantity rather than specific
>elements?
>
>Thanks,
>Tony.
>
>
>
>>-----Original Message-----
>>From: owner-dm at eso.org [mailto:owner-dm at eso.org] On Behalf Of Ed Shaya
>>Sent: 22 January 2004 15:56
>>To: dm at ivoa.net
>>Subject: Quantity "tables"
>>
>>
>>This is a cross-post with VOTable.
>>
>>Simply put XML is hierarchical and a table is not. Hence,
>>there is this misfit between XML tools (XQuery, XPath, XSLT,
>>WebServices) and our XML/Table efforts (Astrores, VOTable,
>>XDF, Dataset, etc). XML's hierarchies make it more suitable
>>for describing an object's structure. Tables are compact and
>>human-friendly, especially when one gets to large (but not too
>>large) amounts of info. We want it all, but we are
>>struggling to make tables fit beautifully into XML, and
>>falling into circles of inconsistencies.
>>
>>In true XML, tables are something to convert to or from.
>>XHTML has tables explicitly described, but XHTML is a display
>>language. One transforms from your true XML into XHTML only
>>at display time.
>>
>>XML is meant to interchange with relational databases. Using
>>a schema based on true XML, one creates a database
>>configuration and flattens the documents into one or several
>>tables. The tables are now strictly speaking outside of the
>>XML realm but an XML front end allows one to address the data
>>as if it were still in true XML. Although, it should be
>>noted that native XML databases are getting pretty mature and
>>maybe we won't be doing this much longer.
>>
>>I conclude that we should start off with a true XML
>>description of data (ie, not tabular) and then after that
>>matures, rethink tabular formats, but as either a compressed
>>transmission mode or as a display mode or as the internals of
>>an object-relational database. That way, all tools interface
>>with the data in true XML fashions. If I am right, then it
>>would follow that even our image/table display tools like
>>Alladin and Mirage would benefit from a hierarchical view of data.
>>
>>Just to make clear what I mean by a "hierarchical view of
>>data", below is an example of the "non-tabular way". This is
>>just one galaxy and one must imagine that there are many in
>>this object oriented database. It would be easy now to
>>extend this to include additional metadata about each
>>measurement, who observed it, when, with which instrument,
>>etc. It would also be interested to create a little schema
>>for each Quantity/@type. A B_T_Quantity.xsd which extends
>>Quantity could substitute for the <Quantity type="B_T"/> and
>>provide suitable extensions and restrictions on both metadata
>>and datatypes.
>>
>>OK. Now the crux of this all is that the Tabular form of
>>this is done by a auto-flattener that simply turns this into
>>a series of tables exactly as an XML to DB converter does.
>>Now you have a compact form to transfer and one that can go
>>right into your local/private DB. If it is an object
>>relational DB you should be able to access the data with the
>>original true XML schema and XPATH or XQuery.
>>
>>======================================================
>><AstroObject type="galaxy" name="NGC 300">
>> <Quantity type="altname" name="PGC
>>Num"><value>3238</value><units><unitless/></units></Quantity>
>> <Group name="position">
>> <Quantity type="RA
>>
>>
>>J2000"><value>00:54:52.6</value><units><unit>xs:time</unit></u
>>nits></Quantity>
>> <Quantity type="DE
>>J2000"><value>-37:40:57</value><units><unit>sexigesimal</unit>
>></units></Quantity>
>> </Group>
>> <Quantity type="Galactic_long"
>>name="l"><value>299.2306</value><units><unit>degree</unit></un
>>its></Quantity>
>> <Quantity type="Galactic_lat"
>>name="b"><value>-79.4210</value><units><unit>degree</unit></un
>>its></Quantity>
>> <Quantity
>>type="SGL"><value>259.8113</value><units><unit>degree</unit></
>>units></Quantity>
>> <Quantity
>>type="SGB"><value>-9.4984</value><units><unit>degree</unit></u
>>nits></Quantity>
>> <Quantity type="brightness absolute B total"
>>name="B_T"><value>8.95</value><units><unit>magnitude</unit></u
>>nits></Quantity>
>> <Quantity type="extinction I-band"
>>name="A_I"><value>0.02</value><units><unit>magnitude</unit></u
>>nits></Quantity>
>> <Quantity type="extinction B-band"
>>name="A_B"><value>0.055</value><units><unit>magnitude</unit></
>>units></Quantity>
>> <Quantity type="axis ratio b/a" shape
>>name="b/a"><value>0.73</value><unitless/></Quantity>
>> <Quantity type="morphology type T"
>>name="Ttype"><value>7</value><unitless/></Quantity>
>> <Quantity type="morphology type M"
>>name="Mtype"><value>SA(s)d</value><unitless/></Quantity>
>> <Group type="velocity radial">
>> <Quantity type="geocentric" name="V_gsr">
>> <value errorValue="4." >101.</value>
>> <units><unit>km</unit><unit power="-1">s</unit></units>
>> </Quantity>
>> <Quantity type="heliocentric" name="V_helio">
>> <value errorValue="4.">144.</value>
>> <units><unit>km</unit><unit power="-1">s</unit></units>
>> </Quantity>
>> </Group>
>> <Quantity type="linewidth 21cm @20percentOfPeak" name="W20">
>> <value ErrorValue="7.">166.</value>
>> <units><unit>km</unit><unit power="-1">s</unit></units>
>> </Quantity>
>> <Quantity type="distance Cepheid" name="Cepheid dist"><value
>>errorVAlue="2.3"
>>
>>
>>>26.66</value><units><unit>Mpc</unit></units></Quantity>
>>>
>>>
>> <Quantity type="distance TRGB" name="TRGB
>>dist"><value>UNKNOWN</value><units><unit>Mpc</unit></units></Quantity>
>> <Quantity type="distance PNLF" name="PNLF
>>dist"><value>26.9</value><units><unit>Mpc</unit></units></Quantity>
>> <Quantity type="distance SBF" name="SBF
>>dist"><value>UNKNOWN</value><units><unit>Mpc</unit></units></Quantity>
>> <Quantity type="distance TF" name="Tully-Fisher
>>dist"><value>UNKNOWN</value><units><unit>Mpc</unit></units></Quantity>
>> <Quantity type="axes"><valueList>21.9
>>15.5</valueList><units><unit>arcmin</unit></units></Quantity>
>> <photometry>
>> <region>
>> <fitsFile href="HSTDA/retrieve/n300.u65w0201r.fits">
>> <instrument>WFPC2</instrument>
>> <observationDate>2001:05:06</observationDate>
>>
>><rightAscension>1.372291666667E+01</rightAscension>
>> <declination>-3.768333333333E+01</declination>
>> <rotation>168.502</rotation>
>> <filters>F814W</filters>
>> <exposureTime units="second">40.</exposureTime>
>> <proposalId>8599</proposalId>
>> <observer>Boeker</observer>
>> <history>
>> <date>2001:08:24</date>
>> <creator>Felicia Tam</creator>
>> <item>mosaic of all 4 ccds</item>
>> </history>
>> </fitsFile>
>> <fitsFile href="HSTDA/retrieve/n300.u65w0202r.fits">
>> <telescope>HST</telescope>
>> <instrument>WFPC2</instrument>
>> <observationDate>2001:05:06</observationDate>
>>
>><rightAscension>1.372291666667E+01</rightAscension>
>> <declination>-3.768333333333E+01</declination>
>> <rotation>168.502</rotation>
>> <filters>F814W</filters>
>> <exposureTime units="second">300.</exposureTime>
>> <proposalId>8599</proposalId>
>> <observer>Boeker</observer>
>> <history>
>> <date>2001:08:24</date>
>> <creator>Felicia Tam</creator>
>> <item>mosaic of all 4 ccds</item>
>> </history>
>> </fitsFile>
>> <fitsFile href="HSTDA/retrieve/n300.u65w0203r.fits">
>> <telescope>HST</telescope>
>> <instrument>WFPC2</instrument>
>> <observationDate>2001:05:06</observationDate>
>>
>><rightAscension>1.372291666667E+01</rightAscension>
>> <declination>-3.768333333333E+01</declination>
>> <rotation>168.502</rotation>
>> <filters>F814W</filters>
>> <exposureTime units="second">300.</exposureTime>
>> <proposalId>8599</proposalId>
>> <observer>Boeker</observer>
>> <history>
>> <date>2001:08:24</date>
>> <creator>Felicia Tam</creator>
>> <item>mosaic of all 4 ccds</item>
>> </history>
>> </fitsFile>
>> </region>
>> <region>
>> <fitsFile href="shoko/n300.fits">
>> <telescope>HST</telescope>
>> <instrument>WFPC2</instrument>
>> <observationDate>2001:07:02</observationDate>
>>
>><rightAscension>1.375416666667E+01</rightAscension>
>> <declination>-3.758000000000E+01</declination>
>> <rotation>-154.402</rotation>
>> <filters>F814W</filters>
>> <exposureTime units="second">600.</exposureTime>
>> <proposalId>9162</proposalId>
>> <observer>Tully</observer>
>> <history>
>> <date>2001:07:09</date>
>> <creator>Shoko Sakai</creator>
>> <item>mosaic of all 4 ccds</item>
>> <item>cosmic ray cleaned and summed</item>
>> </history>
>> </fitsFile>
>> <psFile name="NGC 300 Color-Magnitude Diagram"
>>href="shoko/n300cmd.ps"/>
>> </region>
>> </photometry>
>> <kinematics>
>> <reference>
>> <title>H I studies of the Sculptor group
>>galaxies. VI - NGC
>>300</title>
>>
>><author><initial>D</initial><lastName>Puche</lastName></author>
>>
>> <author><initial>C</initial><lastName>Carignan</lastName></author>
>>
>><author><initial>A</initial><lastName>Bosma</lastName></author>
>> <abstract>A study of the kinematics of the
>>Sculptor group galaxy NGC 300 is presented. VLA observations
>>of the H I line show a dramatically warped H I disk just
>>outside the optical disk. A two-component mass model, fitted
>>to the data, gives a total mass of 2.4E10 solar masses at the
>>last observed point of the rotation curve. This value implies
>>an (M/L_B)global about 11 solar masses/solar luminosity for
>>the galaxy which is compared with the total dynamical
>>(M/L_B)dyn of the group. This comparison suggests that dark
>>matter is probably more concentrated around the galaxies of
>>the group than uniformly distributed in the intergalactic medium.
>> </abstract>
>> <bibcode>1990AJ....100.1468P</bibcode>
>> </reference>
>> </kinematics>
>></galaxy>
>>
>>
>>Ed
>>
>>
>>
>>
>
>
>
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