1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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7 | // * conditions of the Geant4 Software License, included in the file * |
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8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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9 | // * include a list of copyright holders. * |
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10 | // * * |
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11 | // * Neither the authors of this software system, nor their employing * |
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12 | // * institutes,nor the agencies providing financial support for this * |
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13 | // * work make any representation or warranty, express or implied, * |
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14 | // * regarding this software system or assume any liability for its * |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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16 | // * for the full disclaimer and the limitation of liability. * |
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17 | // * * |
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18 | // * This code implementation is the result of the scientific and * |
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19 | // * technical work of the GEANT4 collaboration. * |
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20 | // * By using, copying, modifying or distributing the software (or * |
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21 | // * any work based on the software) you agree to acknowledge its * |
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22 | // * use in resulting scientific publications, and indicate your * |
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23 | // * acceptance of all terms of the Geant4 Software license. * |
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24 | // ******************************************************************** |
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25 | // |
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26 | |
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27 | |
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28 | #include "G4ChordFinderSaf.hh" |
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29 | #include <iomanip> |
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30 | |
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31 | // .......................................................................... |
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32 | |
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33 | G4ChordFinderSaf::G4ChordFinderSaf(G4MagInt_Driver* pIntegrationDriver) |
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34 | : G4ChordFinder(pIntegrationDriver) |
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35 | { |
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36 | // check the values and set the other parameters |
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37 | // fNoInitialRadBig=0; fNoInitialRadSmall=0; |
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38 | // fNoTrialsRadBig=0; fNoTrialsRadSmall=0; |
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39 | |
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40 | } |
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41 | |
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42 | // .......................................................................... |
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43 | |
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44 | G4ChordFinderSaf::G4ChordFinderSaf( G4MagneticField* theMagField, |
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45 | G4double stepMinimum, |
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46 | G4MagIntegratorStepper* pItsStepper ) |
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47 | : G4ChordFinder( theMagField, stepMinimum, pItsStepper ) |
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48 | { |
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49 | // Let G4ChordFinder create the Driver, the Stepper and EqRhs ... |
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50 | // ... |
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51 | } |
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52 | |
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53 | // ...................................................................... |
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54 | |
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55 | // ...................................................................... |
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56 | |
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57 | G4ChordFinderSaf::~G4ChordFinderSaf() |
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58 | { |
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59 | if( SetVerbose(0) ) { PrintStatistics(); } |
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60 | // Set verbosity 0, so that will be called in base class again |
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61 | } |
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62 | |
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63 | void |
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64 | G4ChordFinderSaf::PrintStatistics() |
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65 | { |
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66 | // Print Statistics |
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67 | G4cout << "G4ChordFinderSaf statistics report: " << G4endl; |
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68 | G4ChordFinder::PrintStatistics(); |
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69 | |
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70 | /******************* |
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71 | G4cout |
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72 | << " No radbig calls " << std::setw(10) << fNoInitialRadBig |
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73 | << " trials " << std::setw(10) << fNoTrialsRadBig |
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74 | << " - over " << std::setw(10) << fNoTrialsRadBig - fNoInitialRadBig |
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75 | << G4endl |
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76 | << " No radsm calls " << std::setw(10) << fNoInitialRadSmall |
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77 | << " trials " << std::setw(10) << fNoTrialsRadSmall |
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78 | << " - over " << std::setw(10) << fNoTrialsRadSmall - fNoInitialRadSmall |
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79 | << G4endl; |
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80 | G4cout |
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81 | << " *** Limiting stepTrial via if Delta_chord < R_curvature " |
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82 | << " for large to angle from Delta_chord / R_curv " |
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83 | << " and for small with multiple " << GetMultipleRadius() |
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84 | << G4endl; |
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85 | ********************/ |
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86 | } |
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87 | |
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88 | |
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89 | // G4SafetyDist:: |
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90 | // inline |
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91 | G4double |
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92 | CalculatePointSafety(G4ThreeVector safetyOrigin, |
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93 | G4double safetyRadius, |
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94 | G4ThreeVector point) |
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95 | { |
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96 | G4double pointSafety= 0.0; |
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97 | |
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98 | G4ThreeVector OriginShift = point - safetyOrigin ; |
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99 | G4double MagSqShift = OriginShift.mag2() ; |
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100 | if( MagSqShift < sqr(safetyRadius) ){ |
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101 | pointSafety = safetyRadius - std::sqrt(MagSqShift) ; |
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102 | } |
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103 | |
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104 | return pointSafety; |
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105 | } |
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106 | |
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107 | // inline |
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108 | G4bool |
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109 | CalculatePointInside(G4ThreeVector safetyOrigin, |
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110 | G4double safetyRadius, |
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111 | G4ThreeVector point) |
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112 | { |
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113 | G4ThreeVector OriginShift = point - safetyOrigin ; |
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114 | return ( OriginShift.mag2() < safetyRadius*safetyRadius ); |
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115 | } |
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116 | |
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117 | G4double |
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118 | G4ChordFinderSaf::FindNextChord( const G4FieldTrack& yStart, |
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119 | G4double stepMax, |
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120 | G4FieldTrack& yEnd, // Endpoint |
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121 | G4double& dyErrPos, // Error of endpoint |
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122 | G4double epsStep, |
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123 | G4double* pStepForAccuracy, |
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124 | const G4ThreeVector latestSafetyOrigin, |
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125 | G4double latestSafetyRadius |
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126 | ) |
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127 | // Returns Length of Step taken |
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128 | { |
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129 | // G4int stepRKnumber=0; |
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130 | G4FieldTrack yCurrent= yStart; |
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131 | G4double stepTrial, stepForAccuracy; |
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132 | G4double dydx[G4FieldTrack::ncompSVEC]; |
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133 | |
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134 | // 1.) Try to "leap" to end of interval |
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135 | // 2.) Evaluate if resulting chord gives d_chord that is good enough. |
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136 | // 2a.) If d_chord is not good enough, find one that is. |
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137 | |
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138 | G4bool validEndPoint= false; |
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139 | G4double dChordStep, lastStepLength; // stepOfLastGoodChord; |
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140 | |
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141 | GetIntegrationDriver()-> GetDerivatives( yCurrent, dydx ) ; |
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142 | |
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143 | G4int noTrials=0; |
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144 | const G4double safetyFactor= GetFirstFraction(); // was 0.999 |
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145 | |
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146 | // Figure out the starting safety |
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147 | G4double startSafety= |
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148 | CalculatePointSafety( latestSafetyOrigin, |
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149 | latestSafetyRadius, |
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150 | yCurrent.GetPosition() ); |
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151 | |
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152 | G4double |
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153 | likelyGood = std::max( startSafety , |
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154 | safetyFactor * GetLastStepEstimateUnc() ); |
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155 | |
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156 | stepTrial = std::min( stepMax, likelyGood ); |
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157 | |
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158 | G4MagInt_Driver *pIntgrDriver= G4ChordFinder::GetIntegrationDriver(); |
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159 | G4double newStepEst_Uncons= 0.0; |
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160 | do |
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161 | { |
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162 | G4double stepForChord; |
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163 | yCurrent = yStart; // Always start from initial point |
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164 | |
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165 | // ************ |
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166 | pIntgrDriver->QuickAdvance( yCurrent, dydx, stepTrial, |
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167 | dChordStep, dyErrPos); |
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168 | // ************ |
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169 | |
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170 | G4ThreeVector EndPointCand= yCurrent.GetPosition(); |
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171 | G4bool endPointInSafetySphere= |
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172 | CalculatePointInside(latestSafetyOrigin, latestSafetyRadius, EndPointCand); |
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173 | |
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174 | // We check whether the criterion is met here. |
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175 | validEndPoint = AcceptableMissDist(dChordStep) |
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176 | || endPointInSafetySphere; |
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177 | // && (dyErrPos < eps) ; |
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178 | |
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179 | lastStepLength = stepTrial; |
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180 | |
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181 | // This method estimates to step size for a good chord. |
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182 | stepForChord = NewStep(stepTrial, dChordStep, newStepEst_Uncons ); |
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183 | |
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184 | if( ! validEndPoint ) { |
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185 | if( stepTrial<=0.0 ) |
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186 | stepTrial = stepForChord; |
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187 | else if (stepForChord <= stepTrial) |
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188 | // Reduce by a fraction, possibly up to 20% |
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189 | stepTrial = std::min( stepForChord, |
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190 | GetFractionLast() * stepTrial); |
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191 | else |
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192 | stepTrial *= 0.1; |
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193 | |
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194 | // if(dbg) G4cerr<<"Dchord too big. Try new hstep="<<stepTrial<<G4endl; |
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195 | } |
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196 | // #ifdef TEST_CHORD_PRINT |
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197 | // TestChordPrint( noTrials, lastStepLength, dChordStep, stepTrial ); |
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198 | // #endif |
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199 | |
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200 | noTrials++; |
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201 | } |
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202 | while( ! validEndPoint ); // End of do-while RKD |
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203 | |
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204 | AccumulateStatistics( noTrials ); |
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205 | |
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206 | // Should we update newStepEst_Uncons for a 'long step' via safety ?? |
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207 | if( newStepEst_Uncons > 0.0 ){ |
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208 | SetLastStepEstimateUnc( newStepEst_Uncons ); |
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209 | } |
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210 | |
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211 | // stepOfLastGoodChord = stepTrial; |
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212 | |
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213 | if( pStepForAccuracy ){ |
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214 | // Calculate the step size required for accuracy, if it is needed |
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215 | G4double dyErr_relative = dyErrPos/(epsStep*lastStepLength); |
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216 | if( dyErr_relative > 1.0 ) { |
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217 | stepForAccuracy = |
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218 | pIntgrDriver->ComputeNewStepSize( dyErr_relative, |
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219 | lastStepLength ); |
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220 | }else{ |
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221 | stepForAccuracy = 0.0; // Convention to show step was ok |
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222 | } |
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223 | *pStepForAccuracy = stepForAccuracy; |
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224 | } |
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225 | |
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226 | #ifdef TEST_CHORD_PRINT |
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227 | static int dbg=0; |
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228 | if( dbg ) |
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229 | G4cout << "ChordF/FindNextChord: NoTrials= " << noTrials |
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230 | << " StepForGoodChord=" << std::setw(10) << stepTrial << G4endl; |
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231 | #endif |
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232 | |
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233 | yEnd= yCurrent; |
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234 | return stepTrial; |
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235 | } |
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