Code revision:
[u/mrichter/AliRoot.git] / MUON / AliMUONResponseV0.cxx
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a9e2aefa 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
88cb7938 16/* $Id$ */
a9e2aefa 17
a9e2aefa 18#include <TMath.h>
19#include <TRandom.h>
20
30178c30 21#include "AliMUONResponseV0.h"
22#include "AliSegmentation.h"
a9e2aefa 23
d5bfadcc 24ClassImp(AliMUONResponseV0)
25
30178c30 26//__________________________________________________________________________
27AliMUONResponseV0::AliMUONResponseV0()
28 : AliMUONResponse()
29{
30// Default constructor
31
32 fChargeCorrel = 0;
33}
34
d5bfadcc 35 //__________________________________________________________________________
36void AliMUONResponseV0::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3)
37{
38 // Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3")
39 // in the X direction, perpendicular to the wires,
40 // and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4")
41 // in the same direction
42 fSqrtKx3 = SqrtKx3;
43 fKx2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKx3);
44 Float_t cx1 = fKx2 * fSqrtKx3 / 4. / TMath::ATan(Double_t(fSqrtKx3));
45 fKx4 = cx1 / fKx2 / fSqrtKx3;
46}
47
48 //__________________________________________________________________________
49void AliMUONResponseV0::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3)
50{
51 // Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3")
52 // in the Y direction, along the wires,
53 // and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4")
54 // in the same direction
55 fSqrtKy3 = SqrtKy3;
56 fKy2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKy3);
57 Float_t cy1 = fKy2 * fSqrtKy3 / 4. / TMath::ATan(Double_t(fSqrtKy3));
58 fKy4 = cy1 / fKy2 / fSqrtKy3;
59}
60
a9e2aefa 61Float_t AliMUONResponseV0::IntPH(Float_t eloss)
62{
63 // Calculate charge from given ionization energy loss
64 Int_t nel;
4ac9d21e 65 nel= Int_t(eloss*1.e9/27.4);
a9e2aefa 66 Float_t charge=0;
67 if (nel == 0) nel=1;
68 for (Int_t i=1;i<=nel;i++) {
01997fa2 69 Float_t arg=0.;
70 while(!arg) arg = gRandom->Rndm();
71 charge -= fChargeSlope*TMath::Log(arg);
a9e2aefa 72 }
73 return charge;
74}
75// -------------------------------------------
76
a30a000f 77Float_t AliMUONResponseV0::IntXY(AliSegmentation * segmentation)
a9e2aefa 78{
79// Calculate charge on current pad according to Mathieson distribution
80//
81 const Float_t kInversePitch = 1/fPitch;
82//
83// Integration limits defined by segmentation model
84//
85 Float_t xi1, xi2, yi1, yi2;
86 segmentation->IntegrationLimits(xi1,xi2,yi1,yi2);
87 xi1=xi1*kInversePitch;
88 xi2=xi2*kInversePitch;
89 yi1=yi1*kInversePitch;
90 yi2=yi2*kInversePitch;
91//
92// The Mathieson function
93 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
94 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
95
96 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
97 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
98
99
100 return Float_t(4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*
101 fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)));
102}
103
f7b62f08 104Int_t AliMUONResponseV0::DigitResponse(Int_t digit, AliMUONTransientDigit* /*where*/)
a9e2aefa 105{
106 // add white noise and do zero-suppression and signal truncation
b64652f5 107// Float_t meanNoise = gRandom->Gaus(1, 0.2);
108 // correct noise for slat chambers;
109 // one more field to add to AliMUONResponseV0 to allow different noises ????
4ac9d21e 110 Float_t meanNoise = gRandom->Gaus(1., 0.2);
111 Float_t noise = gRandom->Gaus(0., meanNoise);
a9e2aefa 112 digit+=(Int_t)noise;
ddc10e24 113 if ( digit <= ZeroSuppression()) digit = 0;
4ac9d21e 114 // if ( digit > MaxAdc()) digit=MaxAdc();
115 if ( digit > Saturation()) digit=Saturation();
116
a9e2aefa 117 return digit;
118}
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