- Class description on 5 lines (Coding conventions)
[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
d19b6003 18// -----------------------
19// Class AliMUONMathieson
20// -----------------------
21// Implementation of Mathieson response
22// Separated from other classes by CH. Finck with removing circular
23// dependencies
24
7e4a628d 25#include "AliMUONMathieson.h"
471035eb 26
27#include "AliLog.h"
a713db22 28#include "AliMUONGeometrySegmentation.h"
7e4a628d 29
471035eb 30#include <TClass.h>
31#include <TMath.h>
32#include <TRandom.h>
7e4a628d 33
34ClassImp(AliMUONMathieson)
35
36//__________________________________________________________________________
a713db22 37 AliMUONMathieson::AliMUONMathieson() :
38 fSqrtKx3(0.),
39 fKx2(0.),
40 fKx4(0.),
41 fSqrtKy3(0.),
42 fKy2(0.),
43 fKy4(0.),
8bd8c4ce 44 fPitch(0.),
45 fInversePitch(0.)
7e4a628d 46{
d19b6003 47/// Default constructor
7e4a628d 48
49}
50
51 //__________________________________________________________________________
52void AliMUONMathieson::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3)
53{
d19b6003 54/// Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3")
55/// in the X direction, perpendicular to the wires,
56/// and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4")
57/// in the same direction
7e4a628d 58 fSqrtKx3 = SqrtKx3;
59 fKx2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKx3);
60 Float_t cx1 = fKx2 * fSqrtKx3 / 4. / TMath::ATan(Double_t(fSqrtKx3));
61 fKx4 = cx1 / fKx2 / fSqrtKx3;
62}
63
64 //__________________________________________________________________________
65void AliMUONMathieson::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3)
66{
d19b6003 67/// Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3")
68/// in the Y direction, along the wires,
69/// and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4")
70/// in the same direction
7e4a628d 71 fSqrtKy3 = SqrtKy3;
72 fKy2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKy3);
73 Float_t cy1 = fKy2 * fSqrtKy3 / 4. / TMath::ATan(Double_t(fSqrtKy3));
74 fKy4 = cy1 / fKy2 / fSqrtKy3;
75}
7e4a628d 76
471035eb 77//_____________________________________________________________________________
78Float_t
79AliMUONMathieson::IntXY(Float_t xi1, Float_t yi1, Float_t xi2, Float_t yi2) const
80{
d19b6003 81/// Integrate the Mathieson over x and y
82
8bd8c4ce 83 xi1 *= fInversePitch;
84 xi2 *= fInversePitch;
85 yi1 *= fInversePitch;
86 yi2 *= fInversePitch;
471035eb 87 //
88 // The Mathieson function
89 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
90 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
91
92 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
93 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
94
95
96 return Float_t(4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*
97 fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)));
98}
99
a713db22 100// -------------------------------------------
101Float_t AliMUONMathieson::IntXY(Int_t idDE, AliMUONGeometrySegmentation* segmentation)
102{
d19b6003 103/// Calculate charge on current pad according to Mathieson distribution
104/// using Detection elt
105
a713db22 106// Integration limits defined by segmentation model
107//
108 Float_t xi1, xi2, yi1, yi2;
109 segmentation->IntegrationLimits(idDE, xi1,xi2,yi1,yi2);
471035eb 110 return IntXY(xi1,yi1,xi2,yi2);
a713db22 111}
8bd8c4ce 112
113//______________________________________________________________________________
114void
115AliMUONMathieson::SetPitch(Float_t p1)
116{
d19b6003 117/// Defines the pitch, and store its inverse, which is what is used in fact.
118
8bd8c4ce 119 fPitch = p1;
120 if ( fPitch )
121 {
122 fInversePitch = 1/fPitch;
123 }
124 else
125 {
126 AliError(Form("Invalid pitch %e",p1));
127 fInversePitch = 0.0;
128 }
129}
130