Re: updated geometry

["Mark M. Ito" <marki@jlab.org>]

Now I remember, XALAN...scheiβe...

Beni Zihlmann wrote:
> Hi Mark and All,
> I guess one reason for the current handling is that in this way you do 
> not need to have XERCES and XALAN installed
> if you want just to run the MC. However if we would have all the 
> necessary scripts at hand that would do a full blown installation
> of all the software including the third party once that is needed to 
> do the job then I think it would be a good idea to follow your
> proposal.
> Most people will never work with the geometry file or the data 
> structure of the monte carlo and hence would not need
> XERCES and XALAN. This will be even more true in the future. However a 
> consistent software packaged in the full
> sence is probably also more safe in terms of consistency to avoid any 
> confusion about the results of different MC data
> that has been generated by different people.  This aspect will be very 
> crucial in the future when MC data productions
> are needed to extract physics results from the real data.
> Taking the long term future into account I think we should follow your 
> proposal.
>
> cheers,
> Beni
>
>
>
> Mark M. Ito wrote:
>> Beni,
>>
>> Thanks for getting that done. Sounds like real progress.
>>
>> This brings up a code management issue that I have been wondering 
>> about for some time. It seems like we have a two step process: 
>> check-in new xml-based geometry information, then, by hand, generate 
>> the corresponding Fortran GEANT code, then check in the fortran code. 
>> This procedure violates the usual philosophy of only checking in 
>> "source" materials and allowing a make system to generate "derived" 
>> materials. It seems to have lead to some confusion about what we have 
>> in the Monte Carlo vs. what we have in the geometry. And I suspect 
>> some of the build problems I have had recently have to do with trying 
>> to maintain both "source" and "derived" in the Subversion repository.
>>
>> My naive proposal is that we remove the Fortran GEANT code from the 
>> repository and regenerate it as part of the make system. Then one is 
>> guaranteed consistency between geometry specification and code. Also 
>> (if this can be done) a user can modify the geometry and use it 
>> immediately in the Monte Carlo without having to know the details of 
>> how to generate the Fortran code, i. e., play with a private version 
>> of the geometry without becoming an expert. Is there some fundamental 
>> problem with this? Too computationally expensive? Too many "helper" 
>> applications to install? Also, I have no idea how complicated it is 
>> to generate the Fortran code given you have everything you need 
>> installed.
>>
>> On the subject of helper applications, I think we should be able to 
>> put together enough documentation and scripts to install them on most 
>> systems, especially if the applications are coming to us from 
>> experienced/professional programmers.
>>
>> What do you and others think?
>>
>>  -- Mark
>>
>> Beni Zihlmann wrote:
>>> Dear colleagues,
>>> I updated the geometry in the repository. The geometry now reflects
>>> all the changes and design decisions that have been made lately.
>>> 1) remove outer most CDC layer thereby reducing the CDC radius by 
>>> 1.6 cm
>>>    including the cable runs.
>>> 2) re-route the FDC cables to run upstream
>>> 3) add an 8mm aluminum plate on the inside of the BCAL
>>> 4) the BCAL readout segmentation is 4x6 (sector x layer)
>>>
>>> all these changes are now available the in geometry file 
>>> hddsGeant3.F located in
>>> src/programs/Simulation/HDGeant/
>>>
>>> cheers,
>>> Beni
>>>
>
>