Re: [fluka-discuss]: RE: USRTRACK bins, _tab.lis file

From: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Date: Wed, 7 May 2014 18:31:07 +0200

Hi Ana

I do not understand how the average bin energy is concerned in the
integration process. One needs it in case of logarithmic binning just in
order to plot the differential spectrum dN/dlog(E)=E*dN/dE, but the bin
width dE is anyway enough in order to integrate: (dN/dE)*dE. By the way,
in the *sum.lis file generated by the post-processing utilities invoked by
Flair, you can already find the total and partial integrals (with the
latter ones representing the cumulative spectrum).
If you want to handle the bin width yourself, in case of linear binning
you shall get it from the scoring range divided by the number of bins.

Cheers

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854

On Wed, 7 May 2014, Ferreira De Almeida Lourenco, Ana wrote:

>
> Dear Alessio and all,
>
>
> many thanks for your explanation.
>
>
> On my analysis in order to obtain INTEGRAL BINNED results (fluence in cm-2
> PER ENEGY BIN per primary) I will normally make an average between Emin and
> Emax and multiply that value of each energy bin by the width of the bin. In
> this case the width of the bins won't be exactly the same or I can consider
> they are (since it is just a tiny difference)? 
>
>
> Many thanks!
>
> Best wishes,
>
> Ana
>
> ____________________________________________________________________________
> De: Alessio Mereghetti <Alessio.Mereghetti_at_cern.ch>
> Enviado: quarta-feira, 7 de Maio de 2014 14:30
> Para: Ferreira De Almeida Lourenco, Ana; fluka-discuss_at_fluka.org
> Assunto: RE: USRTRACK bins, _tab.lis file  
> Dear Ana,
>
> the non-sense last digit you see in the energy values is a typical effect
> due to SINGLE PRECISION representation. No worries about it.
>
> Indeed, the post-processing tool which merges the USRTRACK data files uses
> SINGLE PRECISION representation for the energy bins, whereas for the fluence
> values and their statistical analysis it makes use of DOUBLE PRECISION.
> Being the format of number printing set to exponential with 7 digits after
> the "." (but for statistical uncertainties), you randomly get some junk in
> the last digit, whereas fluence/error values are correctly rounded.
>
> Cheers
> Alessio
>
> *********************************
> Alessio Mereghetti
> CERN, EN-STI-EET
> Tel:       +41 (0) 22 76 79564
> Office:    864 2-D13
> *********************************
>
> ____________________________________________________________________________
> From: Ferreira De Almeida Lourenco, Ana [am.lourenco_at_ucl.ac.uk]
> Sent: 07 May 2014 15:28
> To: Alessio Mereghetti; fluka-discuss_at_fluka.org
> Subject: RE: USRTRACK bins, _tab.lis file
>
> Hello Alessio and everyone
>
>
> Sorry about that. Attached you can now find the files.
>
>
> Many thanks!
>
> Best wishes,
>
> Ana
>
> ____________________________________________________________________________
> De: Alessio Mereghetti <Alessio.Mereghetti_at_cern.ch>
> Enviado: quarta-feira, 7 de Maio de 2014 13:25
> Para: Ferreira De Almeida Lourenco, Ana; fluka-discuss_at_fluka.org
> Assunto: RE: USRTRACK bins, _tab.lis file  
> Dear Ana,
>
> you forgot to attach the *_tab.lis file. Moreover, could you also attach the
> .inp and _sum.lis file?
>
> Cheers
> Alessio
>
> *********************************
> Alessio Mereghetti
> CERN, EN-STI-EET
> Tel:       +41 (0) 22 76 79564
> Office:    864 2-D13
> *********************************
>
> ____________________________________________________________________________
> From: owner-fluka-discuss_at_mi.infn.it [owner-fluka-discuss_at_mi.infn.it] on
> behalf of Ferreira De Almeida Lourenco, Ana [am.lourenco_at_ucl.ac.uk]
> Sent: 07 May 2014 13:57
> To: fluka-discuss_at_fluka.org
> Subject: [fluka-discuss]: USRTRACK bins, _tab.lis file
>
> Dear all
>
>
> I'm using a USRTRACK card where I specified my Emin (0.0) and Emax (0.06)
> and the number of Bins (200).
>
>
> When I look at my results on the _tab.lis file is indeed scoring energy on
> 200 bins but I realised that the size of the bins is not exactly the same,
> and I would like to know why? Please find attached an example of my _tab.lis
> file.
>
>
> Many thanks,
>
> Ana
>
>
>
Received on Wed May 07 2014 - 19:37:03 CEST