2.3.3. Run:Data

The Data Merging view permits the user to merge the output files generated by FLUKA into the files that will be subsequently used for plotting or inspection of the results. Flair makes this process transparent to the user with the Process Data page.

grab-data-page.gif

One would expect that the simulation is equivalent to a counting experiment, therefore the data will follow a Poisson distribution and the error will be the square root of the number of events collected. This is true provided that no biasing is used in the simulation. When importance scoring is involved (quite typical and recommended way of working) to calculate correctly the statistical error, apart from the final value one has to record also the square of events/hits for every value needed. This doubles the memory and increases the complexity for special estimators. Therefore, FLUKA is making use of the Central Limit Theorem for calculating the mean value of a quantity scored and the error on the determination of the mean. The theorem states:

The distribution of an average tends to be Normal, even when the distribution from which the average is computed is decidedly non-Normal.

This is the main reason we have to perform several cycles, minimum 5 is recommended to simulate correctly a Normal distribution, and then sum-up and average the results. In FLUKA this is done automatically with the us?suw utilities, Where ? can be:

  • b = USRBIN.gifUSRBIN

  • r = RESNUCLE.gifRESNUCLEi

  • t = USRTRACK.gifUSRTRACK or USRCOLL.gifUSRCOLL

  • x = USRBDX.gifUSRBDX

  • y = USRYIELD.gifUSRYIELD

These programs expect as input a list of binary files generated from FLUKA with the respective card and using as unit a negative number, and in the end they generate a set of output files both binary, text and tabulated with the results.

On the right side the window contains two list boxes

Top:

the list of detectors (scoring units USRxxx) requested for each run. Automatically a default name will be assigned in the form of “input-name”_”card”_”unit”. The user with the buttons on the right can delete the file, create a new one or rename it. The default rule for generating the files can be configured in the Preferences Preferences dialog under the Data section

Bottom:

the list of files associated with each detector

2.3.3.1. Ribbon

Command group

Label

Shortcut

Description

scan32.gif Scan

Scan input for possible detector cards.

Warning

Only the BINARY files will appear, the ASCII files cannot be merged!

add.gif New

Add a new detector command for processing

clone.gif Clone

Ctrl-D

Clone

x.gif Remove

Del

Remove a detector file from processing

Files group

Label

Shortcut

Description

refresh32.gif Refresh

Ctrl-R

Re-scan the directory for new files

add.gif Add

Ins

Manually include file(s) to the processing list

x.gif Delete

Del

Remove selected file(s) from the processing list

filter.gif Rules

Open the filter dialog modify the rules of inclusion of data files. (see below)

Action group

Label

Shortcut

Description

clean32.gif Clean

Delete all generated detector files

compress32.gif Process

Ctrl-Enter

pressing the Process button flair will run the appropriate FLUKA utilities to merge the selected data files from the Usrxx listbox. A dialog will confirm the outcome of the operation.

Note

The FLUKA utilities usually generate more than one output files. Typically the merge binary data file has the requested name while for a text file is generated with the extension _sum.lis, and a tabulated one with the extension _tab.lis

2.3.3.2. File Selection Rules

The File Selection Rules dialog permits to user to modify the automatic selection criteria of the files for each output. The dialog gives the possibility to dynamically include or remove files from the processing list, by using a set of patterns. For the moment the dialog is low level and requires some knowledge of regular expressions. Flair automatically adds two default rules for each scoring file.

grab-scan_dialog.gif

The rules in the dialog are executed sequentially until a match is successful.

Rules syntax:

First character defines the action. It accepts:

+ include a file
- remove a file

The rest corresponds to the regular expression that will be checked for match against the file. Some of the most important special characters are:

^ beginning of the string
$ end of the string
. match any character
? repeat previous match zero or one time
+ repeat previous match one or more times
* repeat previous match zero or more times
\d digit 0-9
\D everything but a digit
else any other character is matched literally

For a complete reference please see the python regular expressions