Geant4 11.2.2
Toolkit for the simulation of the passage of particles through matter
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G4INCL::IFunction1D Class Referenceabstract

#include <G4INCLIFunction1D.hh>

+ Inheritance diagram for G4INCL::IFunction1D:

Public Types

typedef G4double(*const) ManipulatorFunc(const G4double)
 Typedef to simplify the syntax of inverseCDFTable.
 

Public Member Functions

 IFunction1D ()
 
 IFunction1D (const G4double x0, const G4double x1)
 
virtual ~IFunction1D ()
 
virtual G4double getXMinimum () const
 Return the minimum allowed value of the independent variable.
 
virtual G4double getXMaximum () const
 Return the maximum allowed value of the independent variable.
 
virtual G4double operator() (const G4double x) const =0
 Compute the value of the function.
 
virtual G4double integrate (const G4double x0, const G4double x1, const G4double step=-1.) const
 Integrate the function between two values.
 
IFunction1Dprimitive () const
 Return a pointer to the (numerical) primitive to this function.
 
InterpolationTableinverseCDFTable (ManipulatorFunc fWrap=0, const G4int nNodes=60) const
 Return a pointer to the inverse of the CDF of this function.
 

Protected Attributes

G4double xMin
 Minimum value of the independent variable.
 
G4double xMax
 Maximum value of the independent variable.
 

Detailed Description

1D function interface

Definition at line 58 of file G4INCLIFunction1D.hh.

Member Typedef Documentation

◆ ManipulatorFunc

G4double(*const) G4INCL::IFunction1D::ManipulatorFunc(const G4double)

Typedef to simplify the syntax of inverseCDFTable.

Definition at line 93 of file G4INCLIFunction1D.hh.

Constructor & Destructor Documentation

◆ IFunction1D() [1/2]

G4INCL::IFunction1D::IFunction1D ( )
inline

Definition at line 60 of file G4INCLIFunction1D.hh.

60 :
61 xMin(0.),
62 xMax(0.)
63 {};
G4double xMin
Minimum value of the independent variable.
G4double xMax
Maximum value of the independent variable.

◆ IFunction1D() [2/2]

G4INCL::IFunction1D::IFunction1D ( const G4double x0,
const G4double x1 )
inline

Definition at line 64 of file G4INCLIFunction1D.hh.

64 :
65 xMin(x0),
66 xMax(x1)
67 {};

◆ ~IFunction1D()

virtual G4INCL::IFunction1D::~IFunction1D ( )
inlinevirtual

Definition at line 69 of file G4INCLIFunction1D.hh.

69{};

Member Function Documentation

◆ getXMaximum()

virtual G4double G4INCL::IFunction1D::getXMaximum ( ) const
inlinevirtual

Return the maximum allowed value of the independent variable.

Definition at line 75 of file G4INCLIFunction1D.hh.

75{ return xMax; }

Referenced by inverseCDFTable(), G4INCL::InvFInterpolationTable::InvFInterpolationTable(), and primitive().

◆ getXMinimum()

virtual G4double G4INCL::IFunction1D::getXMinimum ( ) const
inlinevirtual

Return the minimum allowed value of the independent variable.

Definition at line 72 of file G4INCLIFunction1D.hh.

72{ return xMin; }

Referenced by inverseCDFTable(), G4INCL::InvFInterpolationTable::InvFInterpolationTable(), and primitive().

◆ integrate()

G4double G4INCL::IFunction1D::integrate ( const G4double x0,
const G4double x1,
const G4double step = -1. ) const
virtual

Integrate the function between two values.

Parameters
x0lower integration bound
x1upper integration bound
steplargest integration step size; if <0, 45 steps will be used
Returns
$\int_{x_0}^{x_1} f(x) dx$

Definition at line 66 of file G4INCLIFunction1D.cc.

66 {
67 G4double xi = std::max(x0, xMin);
68 G4double xa = std::min(x1, xMax);
70
71 if(x1 <= x0) {
72 sign = -1.0;
73 std::swap(xi, xa);
74 } else
75 sign = 1.0;
76
77 const G4double interval = xa - xi;
78
79 G4int nIntervals;
80 if(step<0.) {
81 nIntervals = 45;
82 } else {
83 nIntervals = G4int(interval/step);
84
85 // Round up nIntervals to the closest multiple of 9
86 G4int remainder = nIntervals % 9;
87 if (remainder != 0)
88 nIntervals += 9 - remainder;
89
90 nIntervals = std::max(nIntervals, 9);
91 }
92
93 const G4double dx = interval/nIntervals;
94 G4double result = (operator()(xi) + operator()(xa)) * integrationCoefficients[0]/2;
95 for(G4int j = 1; j<nIntervals; ++j) {
96 const G4double x = xi + interval*G4double(j)/G4double(nIntervals);
97 const unsigned index = j%9;
98 result += operator()(x) * integrationCoefficients[index];
99 }
100
101 return result*dx*sign;
102
103 }
double G4double
Definition G4Types.hh:83
int G4int
Definition G4Types.hh:85
virtual G4double operator()(const G4double x) const =0
Compute the value of the function.
G4int sign(const T t)

Referenced by primitive().

◆ inverseCDFTable()

InterpolationTable * G4INCL::IFunction1D::inverseCDFTable ( IFunction1D::ManipulatorFunc fWrap = 0,
const G4int nNodes = 60 ) const

Return a pointer to the inverse of the CDF of this function.

The function parameter fWrap is wrapped around the return value of operator(). If fWrap=NULL (default), fWrap=identity.

Definition at line 123 of file G4INCLIFunction1D.cc.

123 {
124 class InverseCDF : public IFunction1D {
125 public:
126 InverseCDF(IFunction1D const * const f, ManipulatorFunc fw) :
127 IFunction1D(f->getXMinimum(), f->getXMaximum()),
128 theFunction(f),
129 normalisation(1./theFunction->integrate(xMin,xMax)),
130 fWrap(fw)
131 {}
132
133 G4double operator()(const G4double x) const {
134 if(fWrap)
135 return fWrap(std::min(1., normalisation * theFunction->integrate(xMin,x)));
136 else
137 return std::min(1., normalisation * theFunction->integrate(xMin,x));
138 }
139 private:
140 IFunction1D const * const theFunction;
141 const G4double normalisation;
142 ManipulatorFunc fWrap;
143 } *theInverseCDF = new InverseCDF(this, fWrap);
144
145 InterpolationTable *theTable = new InvFInterpolationTable(*theInverseCDF, nNodes);
146 delete theInverseCDF;
147 return theTable;
148 }

Referenced by G4INCL::NuclearDensityFactory::createPCDFTable(), G4INCL::NuclearDensityFactory::createRCDFTable(), and G4INCL::NuclearDensityFactory::createRPCorrelationTable().

◆ operator()()

◆ primitive()

IFunction1D * G4INCL::IFunction1D::primitive ( ) const

Return a pointer to the (numerical) primitive to this function.

Definition at line 105 of file G4INCLIFunction1D.cc.

105 {
106 class Primitive : public IFunction1D {
107 public:
108 Primitive(IFunction1D const * const f) :
109 IFunction1D(f->getXMinimum(), f->getXMaximum()),
110 theFunction(f)
111 {}
112
113 G4double operator()(const G4double x) const {
114 return theFunction->integrate(xMin,x);
115 }
116 private:
117 IFunction1D const * const theFunction;
118 } *thePrimitive = new Primitive(this);
119
120 return thePrimitive;
121 }

Member Data Documentation

◆ xMax

G4double G4INCL::IFunction1D::xMax
protected

Maximum value of the independent variable.

Definition at line 106 of file G4INCLIFunction1D.hh.

Referenced by getXMaximum(), and integrate().

◆ xMin

G4double G4INCL::IFunction1D::xMin
protected

Minimum value of the independent variable.

Definition at line 104 of file G4INCLIFunction1D.hh.

Referenced by getXMinimum(), and integrate().


The documentation for this class was generated from the following files: