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## Re: Energy distribution of source as histogram (GPS)

Forum: Event and Track Management
Re: Energy distribution of source as histogram (GPS) (Suhaili Zakaria)
Date: 02 Mar, 2010
From: Fan Lei <Fan Lei>

 On Thu, 25 Feb 2010 03:52:51 GMT, Suhaili Zakaria wrote: ```> Hello > > I have referred to http://reat.space.qinetiq.com/gps/ and examples in > /extended/eventgenerator/exgps/, but I still have questions and > uncertainties on how to use/define energy distribution as histogram > using GPS. > > 1. I am interested with two of the options that can be used to defined > energy distribution, i.e. energy (/gsp/ene/type User ), and arbitrary > point-wise spectrum (/gps/ene/type Arb). However, I am not sure what is > the difference between this two options, and in what conditions they are > best used. Can someone please explain it? ``` User: user defined histogram, i.e. step function like spectrum Arb: point-wise spectrum ```> > 2. To choose a histogram, the command /gps/hist/type is used. In case of > energy it should be /gps/hist/type energy and /gps/hist/type arb for > arbitrary point-wise. > > I suppose you use /gsp/ene/type User with /gps/hist/type energy; and > (/gps/ene/type Arb) with /gps/hist/type arb. Am I correct? ``` Correct! ```> > 3. Next, /gps/hist/point command is used to load the histogram, > where is the energy in MeV and Y is the weight (or area) of the bin. ``` Correct for the "energy" case. is the lower-edge of the the bin, is the area of the bin. Please follow test18.g4mac in http://reat.space.qinetiq.com/gps/examples/examples.htm ```> How do I determine the weight in this case? > > Is the number of particles per energy, but that doesn�t seem right. > ``` In this case you should use the "Arb and "arb" combination, i.e. point-wise distribution. Please follow test19.g4mac in http://reat.space.qinetiq.com/gps/examples/examples.htm ```> I really appreciate and looking forward to any insights/answers/comments > on this matter. Many, many thanks > ```

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1 Re: Energy distribution of source as histogram (GPS)   (Suhaili Zakaria - 08 Mar, 2010)
 to: "Re: Energy distribution of source as histogram (GPS)"
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