1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 #include "AliMUONMathieson.h"
21 #include "AliMUONGeometrySegmentation.h"
27 ClassImp(AliMUONMathieson)
29 //__________________________________________________________________________
30 AliMUONMathieson::AliMUONMathieson() :
40 // Default constructor
44 //__________________________________________________________________________
45 void AliMUONMathieson::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3)
47 // Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3")
48 // in the X direction, perpendicular to the wires,
49 // and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4")
50 // in the same direction
52 fKx2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKx3);
53 Float_t cx1 = fKx2 * fSqrtKx3 / 4. / TMath::ATan(Double_t(fSqrtKx3));
54 fKx4 = cx1 / fKx2 / fSqrtKx3;
57 //__________________________________________________________________________
58 void AliMUONMathieson::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3)
60 // Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3")
61 // in the Y direction, along the wires,
62 // and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4")
63 // in the same direction
65 fKy2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKy3);
66 Float_t cy1 = fKy2 * fSqrtKy3 / 4. / TMath::ATan(Double_t(fSqrtKy3));
67 fKy4 = cy1 / fKy2 / fSqrtKy3;
70 //_____________________________________________________________________________
72 AliMUONMathieson::IntXY(Float_t xi1, Float_t yi1, Float_t xi2, Float_t yi2) const
75 // Integrate the Mathieson over x and y
82 // The Mathieson function
83 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
84 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
86 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
87 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
90 return Float_t(4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*
91 fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)));
94 // -------------------------------------------
95 Float_t AliMUONMathieson::IntXY(Int_t idDE, AliMUONGeometrySegmentation* segmentation)
97 // Calculate charge on current pad according to Mathieson distribution
98 // using Detection elt
100 // Integration limits defined by segmentation model
102 Float_t xi1, xi2, yi1, yi2;
103 segmentation->IntegrationLimits(idDE, xi1,xi2,yi1,yi2);
104 return IntXY(xi1,yi1,xi2,yi2);
107 //______________________________________________________________________________
109 AliMUONMathieson::SetPitch(Float_t p1)
112 // Defines the pitch, and store its inverse, which is what is used in fact.
117 fInversePitch = 1/fPitch;
121 AliError(Form("Invalid pitch %e",p1));