Lego Plots

[Functionality][The AliRun::RunLego(..) Method][Lego Generators]
[Starting Up] [Run] [Look a the results]

Functionality  [Take me back]

Lego plots are generated by tracking so called geantinos through the Geant3 geometry. These geantinos
do not undergo any interaction with the material but allow to sample physical quantities step by step.
The most important of these quantities are the density, radiation length and interaction length. The plots
are represented as 2-dim histograms. The two coordinates of are by default the phi and theta direction of
the geantino. Other coordinate pairs can, however, be chosen.

The AliRun::RunLego(...) Method  [Take me back]


void  RunLego(
const char *setup="Config.C",
Int_t nc1=60, Float_t c1min=2, Float_t c1max=178,
Int_t nc2=60,Float_t c2min=0,Float_t c2max=360,
Float_t rmin=0, Float_t rmax=430,
Float_t zmax=10000,
AliLegoGenerator* gener=NULL

Meaning of the arguments
setup Name of configuration file
nc1, c1min, c1max number of bins, lower and upper limit for the first coordinate
nc2, c2min, c2max number of bins, lower and upper limit for the second coordinate
rmin, rmax upper and lower limit of radial coordinate in (x,y)-plane
zmax upper limit for z-coordinate
gener The lego generator used for the run

If no lego-generator is passed to RunLego the default generator AliLegoGenerator is used.

Lego Generators [Take me back]
Generator Type 1st coordinate  2nd coordinate Origin of geantino
AliLegoGenerator() theta phi (0,0,0)
AliLegoGeneratorEta() phi  eta (0,0,0)
AliLegoGeneratorPhiZ() z phi (0,0,z) theta=90deg
AliLegoGeneratorXYZ("x") y z (0,y,z) 
AliLegoGeneratorXYZ("y") x z (x,0,z)
AliLegoGeneratorXYZ("z") x y (x,y,0)

AliLegiGeneratorXYZ has to be initialized with the name of the axis ("x", "y" or "z") perpendicular to which the origin of the
geantino as varied. The direction of the geantino will be parallel to this axis.

Starting Up [Take me back]

Start AliRoot as usual.
pcandreas% aliroot 

 Warning in <Add>: class AliClassInfo allready in
 Constant Field Map1 created: map= 1, factor=
   *                                         * 
   *        W E L C O M E  to  R O O T       * 
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   *   Version   2.25/03 15 September 2000   * 
   *                                         * 
   *  You are welcome to visit our Web site  * 
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 Compiled with thread support. 

 CINT/ROOT C/C++ Interpreter version 5.14.50, Sep 2
 Type ? for help. Commands must be C++ statements. 
 Enclose multiple statements between { }. 


 root [0] 


Run [Take me back]

Example for run with default generator.
 root [0] gAlice->RunLego("Config.C", 145, -45., 45, 90, 0, 360, 0, 700 , 1000)

Example for run with non default generator.
 root [0] gAlice->RunLego("Config.C", 90, 0, 360, 100, -1, 1, 0, 700 , 1000, new AliLegoGeneratorEta())

Look at the results  [Take me back]

Start a TBrowser
 root [1] new TBrowser()

Select galice.root in the ROOT Files Folder.


Click on one of the histogram icons to display the histogram. Use the Draw Panel from the context menu to select the Lego1 drawing option.