Pythia-Root: Problem in Installation and Running

ROOT
1

Hi,
I tried installing root with pythia support on a Suse-10.2 machine.
The compiler versions are:

[quote]gcc: version 4.1.2 20061115 (prerelease) (SUSE Linux)
g++: version 4.1.2 20061115 (prerelease) (SUSE Linux)
g77: version 3.3.5 20050117 (prerelease) (SUSE Linux)[/quote]
libPythia6.so installation
I built libPythia6.so using the script www-minos.phyast.pitt.edu/~mskim … und.sh.txt and kept the library file (libPythia6.so) in /opt/root/lib

ROOT installation
I installed root as described in root.cern.ch/root/Install.html with $ROOTSYS=/opt/root with the following configuration
./configure --enable-pythia6 --with-pythia6-libdir=/opt/root/lib
The installation didn’t give any error message.

Problem in Running ROOT
However in the root prompt when I tried to run pythiaExample.C I got the following error:

root [1] .L pythiaExample.C root [2] makeEventSample(1000) Error in <TUnixSystem::DynamicPathName>: $HOME/pythia6/libPythia6[.so | .sl | .dl | .a | .dll] does not exist in .:/opt/root/lib::/opt/root/lib:/cern/pro/lib:/opt/root/lib: dlopen error: /opt/root/lib/libPythia6.so: undefined symbol: pdfset_ Load Error: Failed to load Dynamic link library /opt/root/lib/libEGPythia6.so (int)(-1) *** Interpreter error recovered ***

When I manually put pythiaExample.C in $HOME/pythia6 and tried to run root again I got the following error:

root [0] .L pythiaExample.C root [1] makeEventSample(1000) dlopen error: /home/gaurab/pythia6/libPythia6.so: undefined symbol: pdfset_ Load Error: Failed to load Dynamic link library /home/gaurab/pythia6/libPythia6.so (int)(-1) *** Interpreter error recovered ***

Could someone please address this problem?

Cheers,
Gaurab

2

The Minos installation file looks sophisticated and complex.
Please look into our simple installation procedure described at the installation page
root.cern.ch/root/Install.html
and see section “Pythia Event Generators”

Rene

3

Thanks brun,

I did it the way mentioned in that link. Actually there was another problem that I had to take care of.
When I tried to build libPythia6.so, g77 gave some troubles about not able to execute cc1. I had installed that g77 from the suse repository. Build it using gfortran it was successful but still the same problem as I mentioned earlier occurred.
I removed the default g77 and recompiled from source (version 3.4.6).

And now ITS WORKING. Thanks again.

Could you please suggest me where to dig for information on using pythia with root? (I will be trying to get as much as possible from the manual itself)

Cheers,
Gaurab

4

The class TPythia6 is a small C++ interface to Pythia6 and there is nothing special that you should know. You can look at the tutorial at
$ROOTSYS/tutorials/pythia6/pythiaExample.C
for for Pythia itself, look at the Pythia6 documentation.

Rene

5

Hi,

I have already started playing with root (in general) and the pythia6 example code.

Its amazing.

Thanks a lot