[Rivet] alpgen+herwig in agile 1.2.2

[Gavin Hesketh]

Hi Andy,
alpgen+pythia is fine - the vetoing is handled by an internal pythia 
function (for herwig it is done by the alpgen code, hence all the problems).

Perhaps it would make sense for me taking on the development/maintenance 
of the alpgen part of agile, as I might be the main person who knows or 
cares about it at this point? I actually reported the IERROR thing a 
couple of months ago, and I think the continue/return bug was introduced 
in the last update...

cheers,
	Gavin

On 09/05/11 14:05, Andy Buckley wrote:
> Hi Gavin et al. Thanks for the patches... now applied on the AGILe
> trunk. Sorry about the delay!
>
> Since I know virtually nothing about the mechanics of how AlpGen
> interfaces to shower generators (although I'm getting quite familiar
> with HERWIG/JIMMY!), can someone in the know please confirm for me that
> I shouldn't be worried that there is no similar vetoing loop in the
> AlpGenFPythia interface?
>
> Cheers,
> Andy
>
>
> On 28/04/11 17:54, Gavin Hesketh wrote:
>> Hello,
>> Although I'm a bit worried I might be gaining a reputation as an alpgen
>> defender, there is a bug in the new agile which means alpgen+herwig will
>> not run correctly.
>>
>> There are two small tweaks, calling:
>> > FC_HWEVNT.IERROR = -1;
>> and
>> > continue; (instead of return)
>> when UPVETO fails.
>>
>> Calling IERROR ensures the event count is correct at the end of the run
>> (mostly cosmetic, unless people use this to normalise). Calling continue
>> ensures agile does not spit out empty events if upveto fails (which can
>> be very often) - this is more serious, and basically makes it unusable
>> as (eg) rivet aborts on seeing an empty event.
>>
>> The two patched files are attached, the diff is below.
>>
>> cheers,
>> Gavin
>>
>>
>>
>>
>>
>> > diff AlpGenFHerwigJimmy.cc
>> build/AGILe-1.2.2/src/AlpGen/AlpGenFHerwigJimmy.cc
>> 70d70
>> < FC_HWEVNT.IERROR = -1;
>> 72c72
>> < continue;
>> ---
>> > return;
>>
>>
>>
>>
>>
>>
>>
>>
>> > diff AlpGenFHerwig.cc build/AGILe-1.2.2/src/AlpGen/AlpGenFHerwig.cc
>> 57,70c57,65
>> <
>> < while (true) {
>> < FC_HWUINE(); // Initialize event
>> < FC_HWEPRO(); // Generate hard subprocess
>> < // Call the matching routine
>> < int imatch = 0;
>> < FC_UPVETO(&imatch);
>> < if (imatch != 0) {
>> < MSG_DEBUG("Event killed by UPVETO");
>> < FC_HWEVNT.IERROR = -1;
>> < FC_HWUFNE();
>> < continue;
>> < }
>> < break;
>> ---
>> > FC_HWUINE(); // Initialize event
>> > FC_HWEPRO(); // Generate hard subprocess
>> > // Call the matching routine
>> > int imatch = 0;
>> > FC_UPVETO(&imatch);
>> > if (imatch != 0) {
>> > MSG_DEBUG("Event killed by UPVETO");
>> > FC_HWUFNE();
>> > return;
>>
>> AlpGenFHerwig.cc
>>
>>
>> // -*- C++ -*-
>> #include "AGILe/AlpGen/AlpGenFHerwig.hh"
>> #include "AGILe/AlpGen/AlpGenWrapper.hh"
>> #include "AGILe/FHerwig/FHerwigWrapper65.hh"
>> #include "AGILe/Utils.hh"
>> #include "HepMC/HEPEVT_Wrapper.h"
>>
>>
>> //-----------------------------------------------------------------------------
>>
>> // Implementation file for class : AlpGenFHerwig
>> // This is the file-reading interface wrapper only. It contains an
>> instance of
>> // FHerwig which does most of the work. This class is only to provide
>> access to
>> // the parameter
>> // settings.
>> //
>> // Authors: Jon Butterworth
>> // Andy Buckley
>> //-----------------------------------------------------------------------------
>>
>>
>>
>> namespace AGILe {
>>
>>
>> // Standard constructor
>> AlpGenFHerwig::AlpGenFHerwig() {
>> _myName = "AlpGenHerwig";
>>
>> // Set flag to read from LHA event file
>> FC_HWPROC.IPROC = -100;
>> _iprocset = true;
>>
>> // Set the ALPGEN filename to "zhjj" by default
>> FC_AHIO.FILENAME[0] = 'z';
>> FC_AHIO.FILENAME[1] = 'h';
>> FC_AHIO.FILENAME[2] = 'j';
>> FC_AHIO.FILENAME[3] = 'j';
>> }
>>
>>
>> // Set string parameters
>> bool AlpGenFHerwig::setParam(const string& name, const string& value) {
>> // Try AlpGen param handling first
>> bool ok = _alpgen.setParam(name, value);
>> if (ok) return SUCCESS;
>> // Fall back to Herwig param handling
>> ok = FHerwig::setParam(name, value);
>> if (ok) return SUCCESS;
>> // Fail
>> MSG_ERROR("AlpGenHerwig doesn't have a parameter called "<< name);
>> return FAILURE;
>> }
>>
>>
>> // Call event generation with veto routine for MLM matching
>> void AlpGenFHerwig::makeEvent(HepMC::GenEvent& evt) {
>> Generator::makeEvent(evt);
>>
>> while (true) {
>> FC_HWUINE(); // Initialize event
>> FC_HWEPRO(); // Generate hard subprocess
>> // Call the matching routine
>> int imatch = 0;
>> FC_UPVETO(&imatch);
>> if (imatch != 0) {
>> MSG_DEBUG("Event killed by UPVETO");
>> FC_HWEVNT.IERROR = -1;
>> FC_HWUFNE();
>> continue;
>> }
>> break;
>> }
>> FC_HWBGEN(); // Generate parton cascade
>> FC_HWDHOB(); // Do heavy quark decays
>> FC_HWCFOR(); // Do cluster formation
>> FC_HWCDEC(); // Do cluster decays
>> FC_HWDHAD(); // Do unstable particle decays
>> FC_HWDHVY(); // Do heavy flavor decays
>> FC_HWMEVT(); // Add soft underlying event
>> FC_HWUFNE(); // Finish event
>> fillEvent(evt);
>> return;
>> }
>>
>>
>> }
>>
>>
>> // Class factory
>> extern "C" {
>> AGILe::Generator* create() { return new AGILe::AlpGenFHerwig(); }
>> void destroy(AGILe::Generator* gen) { delete gen; }
>> }
>>
>>
>> AlpGenFHerwigJimmy.cc
>>
>>
>> // -*- C++ -*-
>> #include "AGILe/AlpGen/AlpGenFHerwigJimmy.hh"
>> #include "AGILe/AlpGen/AlpGenWrapper.hh"
>> #include "AGILe/FHerwig/FHerwigWrapper65.hh"
>> #include "AGILe/FHerwig/JimmyWrapper.hh"
>> #include "AGILe/Utils.hh"
>> #include "HepMC/HEPEVT_Wrapper.h"
>>
>>
>> //-----------------------------------------------------------------------------
>>
>> // Implementation file for class : AlpGenFHerwigJimmy
>> // This is the file-reading interface wrapper only. It contains an
>> instance of
>> // FHerwigJimmy which does most of the work. This class is only to
>> provide access to
>> // the parameter
>> // settings.
>> //
>> // Authors: Jon Butterworth
>> // Andy Buckley
>> //-----------------------------------------------------------------------------
>>
>>
>>
>> namespace AGILe {
>>
>>
>> // Standard constructor
>> AlpGenFHerwigJimmy::AlpGenFHerwigJimmy() {
>> // Set flag to read from LHA event file
>> FC_HWPROC.IPROC = -100;
>> _iprocset = true;
>>
>> // Set the ALPGEN filename to "zhjj" by default
>> FC_AHIO.FILENAME[0] = 'z';
>> FC_AHIO.FILENAME[1] = 'h';
>> FC_AHIO.FILENAME[2] = 'j';
>> FC_AHIO.FILENAME[3] = 'j';
>> }
>>
>>
>> // Set string parameters
>> bool AlpGenFHerwigJimmy::setParam(const string& name, const string&
>> value) {
>> // Try AlpGen param handling first
>> bool ok = _alpgen.setParam(name, value);
>> if (ok) return SUCCESS;
>> // Fall back to Herwig+Jimmy param handling
>> ok = FHerwigJimmy::setParam(name, value);
>> if (ok) return SUCCESS;
>> // Fail
>> MSG_ERROR("AlpGenHerwigJimmy doesn't have a parameter called "<< name);
>> return FAILURE;
>> }
>>
>>
>> // Call event generation with veto routine for MLM matching
>> void AlpGenFHerwigJimmy::makeEvent(HepMC::GenEvent& evt) {
>> Generator::makeEvent(evt);
>> while (true) {
>> int counter(0);
>> // Repeat the first stages of event generation until multiple
>> // scattering succeeds (or isn't run at all).
>> while (true) {
>>
>> FC_HWUINE(); // Initialize event
>> FC_HWEPRO(); // Generate hard subprocess
>>
>> // Call the AlpGen matching routine
>> int imatch = 0;
>> FC_UPVETO(&imatch);
>> if (imatch != 0) {
>> MSG_DEBUG("Event killed by UPVETO");
>> FC_HWEVNT.IERROR = -1;
>> FC_HWUFNE();
>> continue;
>> }
>>
>> counter += 1;
>>
>> FC_HWBGEN(); // Generate parton cascade
>>
>> // Call the multiple scattering routine with the abort flag.
>> // If abort is returned with value 1 (true), then abandon the
>> // event. This implementation makes sure that the event generation
>> // continues if multiple scattering is disabled (MSFLAG != 1)
>> int abort(0);
>> if (FC_JMPARM.MSFLAG == 1) FC_HWMSCT(&abort);
>> // If MS is okay or disabled, escape the loop and
>> // continue with the decays and hadronisation.
>> if (abort == 0) {
>> MSG_DEBUG("Num attempts to make MPI = "<< counter);
>> break;
>> }
>>
>> // Check for too many attempts to make MPI scatters
>> if (counter> 100) {
>> throw runtime_error("Too many attempts to make MPI in FHerwigJimmy");
>> }
>> }
>> FC_HWDHOB(); // Do heavy quark decays
>> if (_doHadronise) {
>> FC_HWCFOR(); // Do cluster formation
>> FC_HWCDEC(); // Do cluster decays
>> FC_HWDHAD(); // Do unstable particle decays
>> FC_HWDHVY(); // Do heavy flavor decays
>> }
>> FC_HWMEVT(); // Add soft underlying event
>> FC_HWUFNE(); // Finish event
>> if (FC_HWEVNT.IERROR == 0) break;
>> }
>> clearEvent(evt);
>> fillEvent(evt);
>> }
>>
>>
>> }
>>
>>
>> // Class factory
>> extern "C" {
>> AGILe::Generator* create() { return new AGILe::AlpGenFHerwigJimmy(); }
>> void destroy(AGILe::Generator* gen) { delete gen; }
>> }
>>
>>
>>
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>
>