include/Geant4/G4FieldUtils.hh

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0024 //
0025 // Helper namespace field_utils
0026 //
0027 // Description:
0028 //
0029 //  Simple methods to extract vectors from arrays in conventions of
0030 //  the magnetic field integration.
0031
0032 // Author: Dmitry Sorokin, Google Summer of Code 2017
0033 // Supervision: John Apostolakis, CERN
0034 // --------------------------------------------------------------------
0035 #ifndef G4FIELD_UTILS_HH
0036 #define G4FIELD_UTILS_HH
0037
0038 #include "G4FieldTrack.hh"
0039 #include "G4Types.hh"
0040 #include "G4ThreeVector.hh"
0041
0042 namespace field_utils
0043 {
0044
0045   using State = G4double[G4FieldTrack::ncompSVEC];
0046
0047   template <unsigned int N>
0048   using ShortState = G4double[N];
0049
0050   enum class Value3D
0051   {
0052     Position = 0,
0053     Momentum = 3,
0054     Spin = 9
0055   };
0056
0057   enum class Value1D
0058   {
0059     KineticEnergy = 6,
0060     LabTime = 7,
0061     ProperTime = 8
0062   };
0063
0064   template <typename ArrayType>
0065   G4double getValue(const ArrayType& array, Value1D value);
0066
0067   template <typename ArrayType>
0068   G4double getValue2(const ArrayType& array, Value1D value);
0069
0070   template <typename ArrayType>
0071   G4double getValue(const ArrayType& array, Value3D value);
0072
0073   template <typename ArrayType>
0074   G4double getValue2(const ArrayType& array, Value3D value);
0075
0076   template <typename ArrayType>
0077   G4ThreeVector makeVector(const ArrayType& array, Value3D value);
0078
0079   G4double absoluteError(
0080     const G4double y[],
0081     const G4double yerr[],
0082     G4double hstep);
0083
0084   G4double relativeError2(
0085     const G4double y[],
0086     const G4double yerr[],
0087     G4double hstep,
0088     G4double errorTolerance);
0089
0090   G4double relativeError(
0091     const G4double y[],
0092     const G4double yerr[],
0093     G4double hstep,
0094     G4double errorTolerance);
0095
0096   template <typename SourceArray, typename TargetArray>
0097   void setValue(const SourceArray& src, Value1D value, TargetArray& trg);
0098
0099   template <typename SourceArray, typename TargetArray, typename ...TargetArrays>
0100   void setValue(const SourceArray& src, Value1D value,
0101                 TargetArray& trg, TargetArrays&... trgs);
0102
0103   void copy(G4double dst[], const G4double src[],
0104             std::size_t size = G4FieldTrack::ncompSVEC);
0105
0106   G4double inverseCurvatureRadius(G4double particleCharge,
0107                                   G4double momentum, G4double BField);
0108
0109   template <typename T>
0110   T clamp(T value, T lo, T hi);
0111
0112 } // field_utils
0113
0114 #include "G4FieldUtils.icc"
0115
0116 #endif