MadGraph5_aMC@NLO

Pythia83.cc file

Asked by Claudio Severi

Hello everyone,
the Pythia83.cc file, found in the MCatNLO subfolder of any process folder, is different from the Pythia82.cc file found in the same place. One difference is that the two lines:

 void pyabeg_(int&,char(*)[wgts_info_len_used]);
 char cwgtinfo_weights_info[1024][wgts_info_len_used];

get replaced by:

 void pyabeg_(int&,char(*)[50]);
 char cwgtinfo_weights_info[1024][50];

I am having troubles compiling the Pythia83.cc file, as the length [50] clashes with the definition of wgts_info_len_used (set to 80) in LHEFRead.h.

Is it safe to roll back to the 82 version in this case, even when using pythia 8.3?

Claudio

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
Paolo Torrielli Edit question
Solved by:
Claudio Severi
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Revision history for this message
Paolo Torrielli (paolotorriell) said : 		#1

Dear Claudio,
thanks for spotting this, which seems just to be an inconsistency.
Could you try if it works by replacing

void pyabeg_(int&,char(*)[50]);
char cwgtinfo_weights_info[1024][50];

with

void pyabeg_(int&,char(*)[wgts_info_len_used]);
char cwgtinfo_weights_info[1024][wgts_info_len_used];

in Pythia83.cc?

If it works, as it is expected, I'll then fix it in the next release.

Best.
Paolo

Revision history for this message
Claudio Severi (claudio-severi) said : 		#2

Thank you for your quick reply Paolo,
I changed the two lines to match the 82 file, and 83 now compiles ok.

If this change breaks something else down the line I will let you know, but for now it seems to be working.

Cheers,
Claudio