Adding MUONChamberMaterialBudget.C:
[u/mrichter/AliRoot.git] / MUON / AliMUONMathieson.cxx
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7e4a628d 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
16/* $Id$ */
17
3d1463c8 18//-----------------------------------------------------------------------------
d19b6003 19// Class AliMUONMathieson
20// -----------------------
21// Implementation of Mathieson response
22// Separated from other classes by CH. Finck with removing circular
23// dependencies
3d1463c8 24//-----------------------------------------------------------------------------
d19b6003 25
7e4a628d 26#include "AliMUONMathieson.h"
471035eb 27
28#include "AliLog.h"
7e4a628d 29
471035eb 30#include <TClass.h>
31#include <TMath.h>
32#include <TRandom.h>
7e4a628d 33
5398f946 34/// \cond CLASSIMP
7e4a628d 35ClassImp(AliMUONMathieson)
5398f946 36/// \endcond
7e4a628d 37
38//__________________________________________________________________________
5398f946 39AliMUONMathieson::AliMUONMathieson() :
a713db22 40 fSqrtKx3(0.),
41 fKx2(0.),
42 fKx4(0.),
43 fSqrtKy3(0.),
44 fKy2(0.),
45 fKy4(0.),
8bd8c4ce 46 fPitch(0.),
47 fInversePitch(0.)
7e4a628d 48{
d19b6003 49/// Default constructor
7e4a628d 50
51}
52
5398f946 53//__________________________________________________________________________
54AliMUONMathieson::~AliMUONMathieson()
55{
56/// Destructor
57}
58
7e4a628d 59 //__________________________________________________________________________
60void AliMUONMathieson::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3)
61{
d19b6003 62/// Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3")
63/// in the X direction, perpendicular to the wires,
64/// and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4")
65/// in the same direction
7e4a628d 66 fSqrtKx3 = SqrtKx3;
67 fKx2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKx3);
68 Float_t cx1 = fKx2 * fSqrtKx3 / 4. / TMath::ATan(Double_t(fSqrtKx3));
69 fKx4 = cx1 / fKx2 / fSqrtKx3;
70}
71
72 //__________________________________________________________________________
73void AliMUONMathieson::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3)
74{
d19b6003 75/// Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3")
76/// in the Y direction, along the wires,
77/// and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4")
78/// in the same direction
7e4a628d 79 fSqrtKy3 = SqrtKy3;
80 fKy2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKy3);
81 Float_t cy1 = fKy2 * fSqrtKy3 / 4. / TMath::ATan(Double_t(fSqrtKy3));
82 fKy4 = cy1 / fKy2 / fSqrtKy3;
83}
7e4a628d 84
471035eb 85//_____________________________________________________________________________
86Float_t
87AliMUONMathieson::IntXY(Float_t xi1, Float_t yi1, Float_t xi2, Float_t yi2) const
88{
d19b6003 89/// Integrate the Mathieson over x and y
90
8bd8c4ce 91 xi1 *= fInversePitch;
92 xi2 *= fInversePitch;
93 yi1 *= fInversePitch;
94 yi2 *= fInversePitch;
471035eb 95 //
96 // The Mathieson function
97 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
98 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
99
100 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
101 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
102
103
104 return Float_t(4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*
105 fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)));
106}
107
8bd8c4ce 108//______________________________________________________________________________
109void
110AliMUONMathieson::SetPitch(Float_t p1)
111{
d19b6003 112/// Defines the pitch, and store its inverse, which is what is used in fact.
113
8bd8c4ce 114 fPitch = p1;
115 if ( fPitch )
116 {
117 fInversePitch = 1/fPitch;
118 }
119 else
120 {
121 AliError(Form("Invalid pitch %e",p1));
122 fInversePitch = 0.0;
123 }
124}
125