RE: in place of Hervé(herve.wozniak at newb6.u-strasbg.fr)

[Carlos Rodrigo Blanco]

Hi Gerard

I'm glad to know that I have misunderstood so many things, as I much 
prefer everything that you say in the mail than the impression that I had.

Actually, all my work in theoretical models in the VO was very inspired in 
a very nice "white paper" that you wrote some years ago (where you made 
clear, among other things, that any protocol requiring coordinates was 
obviously not valid for theoretical data).

In what respect to my use of the word "biased", it could seem to be 
pejorative, but I didn't intend that. I just mean that as you have been 
working hardly in cosmological (and other rather complicated) simulations, 
and having you worked for a long time in SNAP/SimDB/SimDAP, you tend to 
follow the same approach and try to adapt a little all the ideas that you 
have developed in that context to make room for microsimulations. But, as 
you start with ideas developed in the context of cosmological simulations, 
the solutions tend to be more based on the characteristics of those 
problems but "relaxed" so that they can be used in another context. I must 
confess that the same happens to me. My ideas are originated in the 
context of theoretical spectra and I try to extend them to allow for 
different kind of models. I once read that someone said: "when the only 
tool that we have is a hammer, we tend to see all problems as nails" ;-)

and we all were aware of the __existence__ of SNAP (then SimDB/SimDAP). I 
haven't said we weren't. But I always understood that SNAP was designed 
for cosmological simulations, wasn't it? And now that it seems to be open 
for other type of simulations, the point that I make is that I don't know 
how I can make an implementation of a model following it. At least, I 
haven't found any document that helps me in that way and none of the talks 
that I have attended (in the Garching workshop in 2008, ivoa meetings and 
so) has taught me about that. Maybe it's my fault and I haven't been able 
to understand something of what I've heard or I haven't listened well, 
that could have happened (and I'm not being ironic). But the fact is that 
I have to confess that I don't really understand SimDB or SimDAP or how I 
could develop something using them. Is there any place where I can, for 
instance, learn what I need to implement a Isochrones model with those 
protocols?

I would need that to be able to discuss these things in a proper way (and 
if the answer is "not yet, but we are working on it" it's ok, but maybe 
I'm missing something)

In any case, I go back to my first comment. I'm glad to see that I was 
wrong in many points and I'll be happy to start with that perspective from 
now on.

Carlos

>
> Dear Carlos
>>
>> But we don't really understand, either, why the SimDB/SimDAP
>> iniciative is promoted to other IVOA groups as the "proposal
>> by the Theory Interest Group" when we, at this group, haven't
>> been able to really discuss it.
>>
> SimDB is not "the proposal", it is "a" proposal. Actually they are two
> proposals.
> I do not understand this criticism (which it is).
> We have presented and discussed SNAP and SimDB/SimDAP in each and every
> interop meeting.
> Miguel and Patrizia have attended a workshop on SNAP in april 2007.
> Patrizia has been more involved in this since SimDB is more her domain than
> Miguel's.
> Most work has happpened inside a "tiger team" that is true, and developments
> have been
> slower than hoped. But Miguel can not have been unaware of the existence of
> the project,
> whether under the name SNAP, or since recently SimDB+SimDAP. And the same
> should be true for you.
> Note that part of the reason for the split from SNAP->SimDB+SimDAP was so
> that different people could be
> in charge of parts of the process, in this case Claudio and Rick pushing the
> process further for SimDAP.
>
>
>> The fact, as I see it, is that this group has been always the
>> "SNAP interest group", the "cosmological simulations interest
>> group" or the "big numerical simulations interest group".
>> It's not really a critizism, I think that we all saw it in
>> this way, both the people interested in that kind of
>> simulations and the people that were interested in other
>> questions. In fact, other things related to theoretical
>> models in the VO, like theoretical spectra models, were
>> discussed somewhere else with no interaction at all with this
>> group. Even at Cambridge, when Miguel asked about the group
>> interest in this things he was aswered with something like
>> "we are not really interested in that, if you are interested,
>> it is your work to promote and lead that subject".
>>
> Carlos, this is a very incorrect, even unfair representation of what
> happened.
>> From the very beginning of the TIG we have been open to all interested
> parties to propose their projects.
> This is why at some point we had an effort to define use cases for example
> to see what could be done.
> At some point, one group decided, as outcome of a meeting in Cambridge, to
> investigate a specification for simulations, N-body and related (mesh)
> simulations. This was called SNAP.
> In Victoria this was first proposed to the IVOA and we explicitly asked
> relevant WG for suggestions how to proceed. This lead to a change in
> direction, from a SIAP clone to an approach mirroring SSA, which includes
> designing a data model on which the protocol can be based.
> In the same meeting we asked whether there was interest in, or need for
> other specifications, precisely because we did not want the TIG to restrict
> itself to one type of theory only. In that same meeting, during discussions
> on SSA, it became clear that that spec would explicitly take into accoutn
> theory spectrsa. For example by not insisiting on spatial coordinates. Still
> we asked whether people wanted other spec, but no one wanted to.
>
> This question was repeated in all interops since then and until the interop
> in Cambridge the answer remained no.
> This changed in Cambridge, when, after again asking for this, this time
> there was interest to go beyond theory spectra. Particularly Miguel, who was
> immediatly put in charge of investigating this further. This was not because
> other people thought it uninteresting, but because Miguel, with his
> background and interest was seen as the perfect person to push this further.
> Similarly Franck LePetit was going to lead a project on semantics for
> theory.
>
>
>> Only recently this group has started to be interested in
>> other kind of theoretical problems that have been labeled as
>> "microsimulations" but biased by the original perspective
>> (and it's perfectly understable).
>>
> What bias is there? I don't understand this.
>
>> Actually, I don't really understand why we should work in a
>> unique idea or protocol. I think that it is as saying that
>> the VO should have only one protocol for observational data
>> and that SSAP, SIAP, ConeSearch, Skynode, TAP, etc should
>> work in converging to an only protocol.
>>
> Sorry you are again completely misrepresenting the situation as I hope you
> see from the previous comments..
>
>> I just hope that this series of mails is the begining of some
>> useful discussion :-)
> Well I hope the discussions can avoid misrepresentations such as the ones
> you made.
> I will give my comments on S3, but have been busy with other work to do so
> already now.
>
>
> Best regards
>
> Gerard
>