[Rivet] Rivet question

[James John Lacey]

Hi Andy,

I implemented a procedure similar to your suggestion and everything is working perfectly! 

This is probably the best solution for this special use case, as I don't imagine this type of functionality is required by the large majority of users.

Thanks again!

Cheers,
Jim 
________________________________________
From: James John Lacey
Sent: 28 February 2016 17:41
To: Andy Buckley
Cc: Rivet
Subject: RE: Rivet question

Hi Andy,

Thanks for the quick response!

I'm just on my way out for the afternoon,.. I'll try this approach out later today and let you know.

Thanks and cheers,
Jim

________________________________________
From: Andy Buckley
Sent: 28 February 2016 17:32
To: James John Lacey
Cc: Rivet
Subject: Re: Rivet question

Hi Jim,

Hmm, good question.

It's not something that we designed Rivet to do, since the only
programmatic output after analysis is meant to be the centrally-managed
histogram objects.

I suppose we could add some general way of passing arbitrary objects
about, but it's not obvious how it would help most users. I think it
would be as easy to do a dynamic_cast to the exact analysis type and use
a method specific to that analysis to do whatever you need. Something
like this (code not at all tested) would work, I think... no
dynamic_cast needed:

AnalysisHandler ah;
MY_SUPER_ANALYSIS myana;
ah.addAnalysis(&myana);
for (int i = 0; i< NEVENTS; ++i) {
   HepMC::GenEvent* evt = get_next_event_from_somewhere();
   ah.analyze(*evt);
   const FourMomentum foo = myana.my_special_feature();
   ...
}

Does that help?

Andy


On 28/02/16 15:53, James John Lacey wrote:
> Hi Andy,
>
> I am developing a Rivet routine for use in standalone code using the C++
> API. The routine is being developed in the context of the simplified
> Higgs cross sections Truth Classifier that has been discussed...
>
> I have everything up and running and can implement a Rivet analysis in
> my C++ code using the AnalysisHandler::analyze(*HepMC::GenEvent) method.
>
> Now given that I am using Rivet projections to compute the objects and
> quantities used in the classification I would like to have Rivet return
> these values so I can use/save them.
>
> My question is: is there a way to retrieve per event information (ex. a
> 4-vector) from Rivet when running in standalone C++ ?,.. ie. for a given
> HepMC event I want to analyze() the event in Rivet and retrieve the
> relevant event information in the form of a double or 4-vector or ... etc.
>
> Thanks in advance for any insight/help you can provide!
>
> Cheers,
> Jim
>


--
Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow