Extracting the cross section error from gridpack generated sample

Asked by Gilberto Tetlalmatzi on 2020-08-11

Dear administrator
I am currently generating event samples using a gridpack. The events are in the format lhe.gz. I am using a python script to extract the cross section through the command

 lhe_this = lhe_parser.EventFile(f)
 xs= lhe_this.cross

where f is the lhe.gz file containing the events, is there also simple way of determining extracting the corresponding error?

Thanks in advance!
Gilberto

Question information

Language:
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Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
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Last query:
2020-08-12
Last reply:
2020-08-19

Hi,

You need to be very careful about error since they are not a unique definition of statistical uncertainty.
For example do you want the error on the cross-section or the statistical error on the sample of the lhe file (which will not be the same).

What you can do is the following:

banner = lhe_this.get_banner()
cross, error = banner.get_cross(witherror=True)

The error is here the error on the estimation of the cross-section.

Cheers,

Olivier

> On 11 Aug 2020, at 15:45, Gilberto Tetlalmatzi <email address hidden> wrote:
>
> New question #692336 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/692336
>
> Dear administrator
> I am currently generating event samples using a gridpack. The events are in the format lhe.gz. I am using a python script to extract the cross section through the command
>
> lhe_this = lhe_parser.EventFile(f)
> xs= lhe_this.cross
>
> where f is the lhe.gz file containing the events, is there also simple way of determining extracting the corresponding error?
>
> Thanks in advance!
> Gilberto
>
>
>
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Gilberto Tetlalmatzi (gtx83) said : #2

Hi Oliver

Thank you very much!. The solution proposed works nicely :).

Cheers

Gilberto

________________________________
From: <email address hidden> <email address hidden> on behalf of Olivier Mattelaer <email address hidden>
Sent: 11 August 2020 17:55:49
To: Tetlalmatzi-Xolocotzi, Gilberto, Dr.
Subject: Re: [Question #692336]: Extracting the cross section error from gridpack generated sample

Your question #692336 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/692336

    Status: Open => Answered

Olivier Mattelaer proposed the following answer:
Hi,

You need to be very careful about error since they are not a unique definition of statistical uncertainty.
For example do you want the error on the cross-section or the statistical error on the sample of the lhe file (which will not be the same).

What you can do is the following:

banner = lhe_this.get_banner()
cross, error = banner.get_cross(witherror=True)

The error is here the error on the estimation of the cross-section.

Cheers,

Olivier

> On 11 Aug 2020, at 15:45, Gilberto Tetlalmatzi <email address hidden> wrote:
>
> New question #692336 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/692336
>
> Dear administrator
> I am currently generating event samples using a gridpack. The events are in the format lhe.gz. I am using a python script to extract the cross section through the command
>
> lhe_this = lhe_parser.EventFile(f)
> xs= lhe_this.cross
>
> where f is the lhe.gz file containing the events, is there also simple way of determining extracting the corresponding error?
>
> Thanks in advance!
> Gilberto
>
>
>
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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