MadGraph5_aMC@NLO

MG5aMC_PY8_interface: hepmc repeated block keys

Asked by Kirtimaan

I have two questions and I am not sure if they are related:
==================================================================
Question 1:
The following is what my tag_1_pythia8_events.hepmc file looks like.

HepMC::Version 2.06.09
HepMC::IO_GenEvent-START_EVENT_LISTING

HepMC::Version 2.06.09
HepMC::IO_GenEvent-START_EVENT_LISTING
E 0 -1 -1.0000000000000000e+00 -1.0000000000000000e+00 -1.0000000000000000e+00 0 0 134 1 2 0 1 1.7819000000000005e-06
N 1 "0"
U GEV MM
.
.
.
HepMC::IO_GenEvent-END_EVENT_LISTING
HepMC::IO_GenEvent-END_EVENT_LISTING

The IO_GenEvent-END_EVENT_LISTING and IO_GenEvent-START_EVENT_LISTING appear to be repeated.
Why ?
==============================================================================
Question 2:

I get the following warnings/errors while running the pythia interface

INFO: Running Pythia8 [arXiv:1410.3012]
Splitting .lhe event file for PY8 parallelization...
Submitting Pythia8 jobs...
Pythia8 shower jobs: 1 Idle, 7 Running, 0 Done [16 seconds]
Pythia8 shower jobs: 0 Idle, 7 Running, 1 Done [1m42s]
Pythia8 shower jobs: 0 Idle, 5 Running, 3 Done [1m42s]
Pythia8 shower jobs: 0 Idle, 4 Running, 4 Done [1m42s]
Pythia8 shower jobs: 0 Idle, 2 Running, 6 Done [1m42s]
Pythia8 shower jobs: 0 Idle, 1 Running, 7 Done [1m43s]
Pythia8 shower jobs: 0 Idle, 0 Running, 8 Done [1m43s]
Merging results from the split PY8 runs...
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
sed: can't read 1d;2d;3d;$d: No such file or directory
INFO: Pythia8 shower finished after 2m00s.
  === Results Summary for run: run_01 tag: tag_1 ===

     Cross-section : 4.211e+04 +- 39.36 pb
     Nb of events : 10000

INFO: storing files of previous run
INFO: Storing Pythia8 files of previous run
INFO: Done

It looks like the run is successful and a hepmc file is generated with some events. But these warnings/ errors look fishy.
==============================================================================================

FYI I am using a local install of pythia(8.219) and HEPMC on my Linux (fedora 22) machine.

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
Stefan Prestel Edit question
Solved by:
Rikkert Frederix
Solved:
Last query:
Last reply:
Revision history for this message
Stefan Weber (stefan0688) said : 		#1

Hi,

I'm having the same problem using MG5 version 2.5.2 with the pythia8 interface on Linux.
(for some standard process, e.g p p > t t~ with the built in SM )

The hepmc file produced by pythia8, plus the MG5 / pythia8 output looks pretty similar to the one outlined by Kirtimaan.

Best,
Stefan

Revision history for this message
Best Rikkert Frederix (frederix) said : 		#2

Dear Stefan and Kirtimaan,

Indeed, there seems to be a bug in the code that only appears on LINUX and not on Mac OS X. The 'sed -i' command (for interactive sed use) works differently on these machines. The current implementation works only on Mac OS X, where most of the MG5_aMC development is done.

As a fix on linux, you can replace in line 4215 of madgraph/interface/madevent_interface.py (and, if need be <YourProcess>/bin/internal/madevent_interface.py) by

                           os.system(' '.join(['sed','-i',"'%s;$d'"%

that is, remove the "''", after the ,'-i', . The reason is that on Mac OS X, the '-i' option of sed requires an (empty) argument, while on LINUX it doesn't.

This should fix and answer both of your questions.

best,
Rikkert

Revision history for this message
Kirtimaan (kirtimaanmohan) said : 		#3

Thanks for the work around Rikkert.

best,
Kirtimaan

Revision history for this message
Kirtimaan (kirtimaanmohan) said : 		#4

Thanks Rikkert Frederix, that solved my question.