Peter, Tim etc,
I've now added most of the required catalogue-related functionality
to GAIA. You can now load a table into TOPCAT, broadcast it to GAIA,
and then have fun making selections of single or multiple rows in
the one and passing them to the other. The new facilities are
documented in the updated gaia.htx/plastic.html.
I'd say this has arrived at the point where the two tools interact
together in a way that actually allows you to do science that
would have been difficult before - for instance you can plot a
colour-magnitude diagram in TOPCAT, then click on particular outliers
to see where they are in the image, or click on symbols
plotted on the image to see where they are in the colour space,
or select an interesting branch in the C-M diagram using TOPCAT's
blob-selection facility and see which objects on the image
fall into that category. To a degree you could do similar
things before, e.g. using the "Condition" field of GAIA's
plot symbols window, or saving tables from one place and loading them
in another, but the fact you can do it a lot more easily and
interactively now means that various things are possible in practice
now which would have been too fiddly to bother with before.
I should say this isn't exactly the first time this sort of thing
has been done, since TOPCAT can already talk in very similar ways
to Aladin, but for people who use GAIA, either for historical
reasons or because they need GAIA's analysis facilities, this
should be a useful development.
I've checked this lot into CVS on the trunk. Since the keoe deadline
was a couple of weeks ago I presume it's too late for that, though
I do recall Tim commenting that the schedule had been put back a bit...
Further comments:
- GAIA uses STILTS, which it looks for in ${STILTS_DIR}, to do
VOTable<->TST conversions. I've updated etc/init/login.in
(and now etc/init/profile.in) accordingly.
- You can currently only do PLASTIC catalogue business in GAIA with
a catalogue that originated from PLASTIC (e.g. was sent by TOPCAT).
You can't take a table that you've acquired from GAIA's Data-Servers
menu and inject that into the PLASTIC system. I should probably
add this.
- The various catalogue receive and send operations are done in a
blocking fashion, without on-screen progress bars or the possibility
for the user to interrupt. I don't know whether this is considered
bad practice within GAIA.
- Sending large catalogue row selections is currently shockingly
inefficient - O(N*M) for transmitting an M-row selection from
an N-row catalogue - so could cause problems for large
(>~1E4-row?) tables. I can't see how to do these in a more
sensible way, at least not without some fairly major reworking
of the AstroCat class or descendants. Peter, maybe you could
take a quick look at PlasticSearch.tcl and see if you
have any bright ideas (if it's not immediately obvious to you
what the problem is let me know and I'll provide more commentary).
- Since GAIA now has access to STILTS, it wouldn't be too much
extra work to provide catalogue load/save facilities for all
the formats supported by STIL (including VOTable). This may
or may not be something you're interested in doing.
Mark
--
Mark Taylor Astronomical Programmer Physics, Bristol University, UK
[log in to unmask] +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/
