Position correctly containers BTR2 BTO2
[u/mrichter/AliRoot.git] / html / howtorun.html
CommitLineData
14c31136 1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2 "http://www.w3.org/TR/REC-html40/loose.dtd">
3<HTML>
4<HEAD>
5<TITLE>How to run AliRoot</TITLE>
6<link rev="made" href="mailto:Federico.Carminati@cern.ch">
7<STYLE>
8BODY {
9 background: #FFFFFF;
10 }
11
12COL, COLGROUP, TABLE, TBODY, TD, TR {
13 color: black;
14 text-decoration: none;
15 border-color: black;
16 border-style: none;
17 background: #FFFFFF;
18 }
19
20</STYLE>
21<link rel="stylesheet" href="http://www.w3.org/StyleSheets/Core/Swiss" type="text/css">
22</HEAD>
23
24<BODY background=#FFFFFF>
25<TABLE>
26<TR>
27<TD><img src="picts/MadHatter.gif" alt="ALICE Off-line Project Logo">
28<TD><img src="picts/howtorun_name.gif" alt="How to Run AliRoot">
29<TD><img src="picts/AliceLogo.gif" alt="ALICE Logo">
30</TR>
31</TABLE>
32
33<h2>How to Run AliRoot</h2>
34
35<h3>For the impatient user</h3>
36
37<p> <a href="picts/menubar.gif">
38<img src="picts/menubar.gif" alt="AliRoot menu bar"
39height=50% align=right></a>
40
41<p> To start up AliRoot after installation just type
42
43<p> <KBD> $ aliroot </KBD>
44
45<p> this starts AliRoot in interactive mode. When the <b>root [0]</b>
46prompt appears, you can start an AliRoot interactive session by creating
47the standard menu
48
49<p> <KBD> root[0] .x menu.C </KBD>
50
51<p> The macro <A HREf="roothtml/examples/menu.C.html">menu.C</A> invokes
52the <A HREF="roothtml/AliRun.html">AliRun</A>::Init() method. In turn this
53calls the configuration file <A
54HREF="roothtml/examples/Config.C.html">Config.C</A> where the configuration
55of the detector and several simulation parameters can be specified.
56
57<p> When the initialisation is finished the <b>root</b> prompt apears
58again and the Root control bar appears.
59
60<p> <a href="picts/display.gif">
61<img src="picts/display.gif" alt="AliRoot Event Display"
62height=30% align=right></a>
63
64<p> You can now select several actions from the menu.
65
66<p> <b>Run</b>
67
68<p> generates to generate an event with the number of tracks and the
69configuration as specified in <A
70HREF="roothtml/examples/Config.C.html">Config.C</A>. The hits deposited
71
72<p> <b> RunLego </b>
73
74<p> <a href="picts/legoex.gif">
75<img src="picts/legoex.gif" alt="Example of Lego Plot"
76height=30% align=right></a>
77
78<p> generates the standard lego plots for radiation and absorption
79length. By default the granularity is 60 rays in theta and 60 rays in phi.
80
81<p> To view the results when this command is finished type:
82
83<p> <KBD> root[0] .x <A HREF="roothtml/examples/lego.C.html">lego.C</A> </KBD>
84
85<p> to change the parameters of the lego run you could specify them
86in the calling sequence of the RunLego method
87ones type:
88
89<p> <KBD> root[3] gAlice->RunLego (your list of parameters) </KBD>
90
91<p> <a href="picts/treex.gif">
92<img src="picts/treex.gif" alt="Example of Tree"
93height=30% align=right></a>
94
95<p> see <A HREF="roothtml/AliRun.html">AliRun</a>::RunLego for details
96
97<p> <b>Menu Trees</b>
98
99<p> This shows a new menu from which you can draw the geometry tree for the
100Alice detectors. Clicking with the right button on the pad with the name of
101a geometrical element give access to a number of graphic and inspect
102functions. Double-clicking on the pad generates a drawing of the specifications
103of the geometry of the element.
104
105<p> <a href="picts/tpcex.gif">
106<img src="picts/tpcex.gif" alt="Example of Picture"
107height=30% align=right></a>
108
109<p> <b>Menu Pictures</b>
110
111<p> From this menu you can draw pretty pictures of the major ALICE components.
112Note that some pictures may take a long time to be produced.
113
114<p> To quit AliRoot
115
116<p> <KBD>root [ ] .q</KBD>
117
118<h3>A more detailed view</h3>
119
120<p> After startup of the <b>aliroot</b> program the simulation
121infrastructure is initialised by the <a
122href="roothtml/AliRun.html">AliRun</a>::Init() method. This method takes
123an argument that is the name of the initialisation script. The default
124name for this script is <a
125href="roothtml/examples/Config.C.html">Config.C</a>. This script
126initialises the version of the different detectors and of the generator to
127be used. In particular some generators can generated a fixed number of
128particles and in this case this number is an argument of the generator
129constructor.
130
131<p> A global variable <var>gAlice</var> holds the pointer to the instance
132of the <a href="roothtml/AliRun.html">AliRun</a> class.
133
134<p> <KBD>root [ ] gAlice->Init()</KBD>
135
136<p> The <em>Init</em> method loads the chosen MonteCarlo (for the moment
137only Geant3 is available in production) and initialises it. Another global
138variable <var>gMC</var> holds the pointer to the instance of the virtual
139MonteCarlo Class <a href="roothtml/AliMC.html">AliMC</a>. This allows to
140access all the functions of the Virtual Monte Carlo interface. Some of the
141functions are specific to Geant3, and these can be accessed recasting this
142pointer to a specific Geant3 pointer via the statement
143
144<p> <KBD>root [ ] TGeant3 g3 = (TGeant3*) gMC</KBD>
145
146<p> <a href="picts/itsex.gif">
147<img src="picts/itsex.gif" alt="Example of Picture"
148height=30% align=right></a>
149
150<p> In particular all the drawing functions of Geant3 are available via
151this interface. To draw a cut view of the ITS following commands
152could be used
153
154<p>
155<KBD>
156root [1] TGeant3 *g3 = (TGeant3*)gMC
157<br>root [2] g3->Gsatt("*","seen",1)
158<br>root [3] g3->Gdrawc("ITSV",1,.1,10,10,.125,.125)
159</KBD>
160
161<p> Note that several TGeant3 functions are also available by clicking with
162the right button on a canvas while in the AliRoot session.
163
164<p> The <a href="roothtml/AliRun.html">AliRun</a>::Run() method starts a run
165composed by a single event. This method takes as argument the number of events
166to be processed. If this number is negative, the run is not terminated and
167more events can be run. If this number is positive, after the indicated number
168of events the run is terminated. No more events can be run.
169
170<h3>Batch processing</h3>
171
172<p> In AliRoot there is really no difference between batch and interactive
173processing. An <a href="roothtml/examples/grun.C.html">elementary macro</a>
174to run AliRoot in batch mode is provided amongst the examples, and it can
175be used in the following way to run a 10 events run
176
177<p> <KBD> aliroot -b grun.C\(10\)</KBD>
178
179<p> Note that the backslashes are necessary to prevent the shell from
180interpreting the brackets.
181
182<hr>
183<address>
184 <script language="JavaScript">
185 document.write("Last modified "+ document.lastModified)
186 // end of script -->
187 </script>
188by <a href="mailto:Federico.Carminati@cern.ch">Federico Carminati</a>
189</address>
190</BODY>
191</HTML>