Hepevt.h
Pasha Murat (murat@cdfsga.fnal.gov)
Wed, 12 Aug 1998 18:17:54 -0500 (CDT)
Hi Rooters,
an issue of interfacing to the existing FORTRAN packages (esp. MC
generators) comes up again and again and I believe we need a policy on it.
In particular, there is a (well-known to many of us) FORTRAN common-block
/HEPEVT/ which gives kind of "standard" interface to MC event generators.
However the one described in ROOT's Hepevt.h is dimensioned to 2000 whereas
all (or almost all) the last versions of event generators have it
dimensioned to 4000 - we move to higher energies...
The definition in Hepevt.h is all right for Pythia 5.7,
however it is inconsistent with HERWIG and Pythia 6.1. This inconsistency
is fatal for the mixed-language code (at least on SGI/IRIX6).
One of the possible solutions would be to change the dimensions
of all the arrays in Hepevt.h to 4000, however in this case it will become
incompatible (I'm afraid) the old (like Pythia 5.7) versions of the event
generators.
Another possibility would be not to distribute libEG by default, but
to build it locally instead (with the proper dimensioned /HEPEVT/)
There also could be other solutions and I believe that this issue
deserves discussion.
- Any opinions ? - regards, pasha.