sPHENIX discussion of software

[pinkenburg <pinkenburg AT bnl.gov>]

Hi folks,

this is the promised backward compatibility breaking change to enable 
running multiple single particle event generators concurrently (the qa 
uses 2 simple event generators). The change is that the pointers to them 
used in setting the generator options are now vectors. For your Fun4All 
macro that means you need to append [0] to them. So what you need to 
modify is:

INPUTGENERATOR::SimpleEventGenerator --> 
INPUTGENERATOR::SimpleEventGenerator[0]
INPUTGENERATOR::VectorMesonGenerator --> 
INPUTGENERATOR::VectorMesonGenerator[0]
INPUTGENERATOR::Gun --> INPUTGENERATOR::Gun[0]

If you actually want to use multiple generators you need to set the 
number you want - have a look at:
https://github.com/sPHENIX-Collaboration/macros/blob/master/detectors/sPHENIX/Fun4All_G4_sPHENIX.C

Adding more generators you address them by [1], [2],...
All event generators have to use the same vertex otherwise the tracking 
dies.

This also takes care of the problem that G4_Tracking.C didn't load 
standalone. But there is no default, so if you do not execute the 
MagnetInit() function in one of the G4_Magnet_*.C macros you need to set 
them in your macro by

G4MAGNET::magfield_rescale = <whatever you think is the scale factor>
G4MAGNET::magfield = <fieldmap>

I doubt the usefulness of this since our fieldmaps need to be read by 
dedicated code which depends on the type of fieldmap. But at least one 
can now include G4_Tracking.C without including a magnet macro first.

Last not least - local files weren't picked up first in all cases. The 
ROOT_INCLUDE_PATH now starts with ./ and changing all include statements 
from #include "" to #include <> makes sure root looks in your local 
directory first for any include.

Chris

--
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Christopher H. Pinkenburg       ;    pinkenburg AT bnl.gov
                                ;    http://www.phenix.bnl.gov/~pinkenbu

Brookhaven National Laboratory  ;    phone: (631) 344-5692
Physics Department Bldg 510 C   ;    fax:   (631) 344-3253
Upton, NY 11973-5000

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