casacore
Public Types | Public Member Functions | Protected Attributes | List of all members
casacore::Function< T, U > Class Template Referenceabstract

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#include <Function.h>

Public Types

typedef FunctionTraits< T >::ArgType ArgType
 
typedef const ArgTypeFunctionArg
 

Public Member Functions

 Function ()
 Constructors. More...
 
 Function (const uInt n)
 
 Function (const Vector< T > &in)
 
 Function (const FunctionParam< T > &other)
 
template<class W , class X >
 Function (const Function< W, X > &other)
 
virtual ~Function ()
 Destructor. More...
 
virtual uInt ndim () const =0
 Returns the number of dimensions of function. More...
 
uInt nparameters () const
 Returns the number of parameters. More...
 
virtual U eval (FunctionArg x) const =0
 Evaluate the function object. More...
 
T & operator[] (const uInt n)
 Manipulate the nth parameter (0-based) with no index check. More...
 
const T & operator[] (const uInt n) const
 
virtual U operator() () const
 Evaluate this function object at xor at x, y. More...
 
virtual U operator() (const ArgType &x) const
 
virtual U operator() (const Vector< ArgType > &x) const
 
virtual U operator() (FunctionArg x) const
 
virtual U operator() (const ArgType &x, const ArgType &y) const
 
virtual U operator() (const ArgType &x, const ArgType &y, const ArgType &z) const
 
virtual const Stringname () const
 Specify the name associated with the function (default will be unknown) More...
 
Boolmask (const uInt n)
 Manipulate the mask associated with the nth parameter (e.g. More...
 
const Boolmask (const uInt n) const
 
const FunctionParam< T > & parameters () const
 Return the parameter interface. More...
 
FunctionParam< T > & parameters ()
 
const Vector< ArgType > & argp () const
 Get arg_p and parset_p. More...
 
Bool parsetp () const
 
void lockParam ()
 Compiler cannot always find the correct 'const' version of parameter access. More...
 
void unlockParam ()
 
virtual void setMode (const RecordInterface &mode)
 get/set the function mode. More...
 
virtual void getMode (RecordInterface &mode) const
 
virtual Bool hasMode () const
 return True if the implementing function supports a mode. More...
 
ostream & print (ostream &os) const
 Print the function (i.e. More...
 
virtual Function< T, U > * clone () const =0
 Return a copy of this object from the heap. More...
 
virtual Function< typename FunctionTraits< T >::DiffType > * cloneAD () const
 
virtual Function< typename FunctionTraits< T >::BaseType > * cloneNonAD () const
 
- Public Member Functions inherited from casacore::Functional< FunctionTraits< T >::ArgType, T >
virtual ~Functional ()
 Destructor. More...
 
virtual T operator() (const FunctionTraits< T >::ArgType &x) const=0
 Map a Domain x into a Range y value. More...
 
- Public Member Functions inherited from casacore::Functional< Vector< FunctionTraits< T >::ArgType >, T >
virtual ~Functional ()
 Destructor. More...
 
virtual T operator() (const Vector< FunctionTraits< T >::ArgType > &x) const=0
 Map a Domain x into a Range y value. More...
 

Protected Attributes

FunctionParam< T > param_p
 The parameters and masks. More...
 
Vector< ArgTypearg_p
 Aid for non-contiguous argument storage. More...
 
Bool parset_p
 Indicate parameter written. More...
 
Bool locked_p
 Indicate that parameters are expected to be locked from changing. More...
 

Detailed Description

template<class T, class U = T>
class casacore::Function< T, U >

Numerical functional interface class

Intended use:

Public interface

Review Status

Reviewed By:
tcornwel
Date Reviewed:
1996/02/22
Test programs:
tGaussian2D

Prerequisite

Synopsis

A Function is used for classes which map a scalar or n-dimensional Vector of type T into a T. The object also has zero or more parameters which can be masked if necessary, and be used in the Fitting module, and, implicitly, in the AutoDiff differentiation module.

The parameter interface is provided by the FunctionParam class.

A Function can have a name() which can be used in generic interfaces.

The function calls implemented are:

The T in the above is the Function::ArgType as derived from the FunctionTraits class. These calls are (in debug mode) tested for the correct number of arguments, after which they call a T eval(FunctionArg x) const = 0 to be implemented in derived classes. The derived class should also implement an uInt ndim() const = 0. The derived class can access the nth parameter with the [n] operator, and the corresponding mask with mask(n) method. The variables are referenced with x[i].

Example

A complete implementation of say an A.sin(2pi.f.x) with parameters amplitude(A) and frequency(f) and variable time(x) could be:

//# Sinusoid.h
#include <casacore/casa/aips.h>
#include <casacore/scimath/Functionals/Function.h>
#include <casacore/casa/BasicSL/Constants.h>
#include <casacore/casa/BasicMath/Math.h>
// The sinusoid class
template<class T> class Sinusoid : public Function<T> {
public:
// For easy reference of the parameters
enum { AMPL=0, FREQ };
// Constructors. Defaults are A=1, f=1
Sinusoid() : Function<T>(2) {
param_p[AMPL] = T(1.0); param_p[FREQ] = T(1.0); }
explicit Sinusoid(const T &ampl) : Function<T>(2) {
param_p[AMPL] = ampl; param_p[FREQ] = T(1.0); }
Sinusoid(const T &ampl, const T &freq) : Function<T>(2) {
param_p[AMPL] = ampl; param_p[FREQ] = freq; }
Sinusoid(const Sinusoid &other) : Function<T>(2) {
param_p[AMPL] = other.param_p[AMPL];
param_p[FREQ] = other.parameter[FREQ]; }
Sinusoid<T> &operator=(const Sinusoid<T> &other) {
if (this != &other) param_p = other.param_p;
return *this; }
virtual ~Sinusoid() {}
// Dimensionality
virtual uInt ndim() const { return 2; }
// Evaluate
virtual T eval(Function<T>::FunctionArg x) const {
return param_p[AMPL]*sin(T(C::_2pi)*param_p[FREQ]*x[0]); }
// Copy it
virtual Function<T> *clone() const { return new Sinusoid<T>(param_p); }
};
FunctionParam< T > param_p
The parameters and masks.
Definition: Function.h:332
virtual Function< T, U > * clone() const =0
Return a copy of this object from the heap.
Function()
Constructors.
Definition: Function.h:212
virtual uInt ndim() const =0
Returns the number of dimensions of function.
virtual U eval(FunctionArg x) const =0
Evaluate the function object.
const ArgType * FunctionArg
Definition: Function.h:207
const Double _2pi
2*pi
unsigned int uInt
Definition: aipstype.h:51
PtrHolder< T > & operator=(const PtrHolder< T > &other)
LatticeExprNode sin(const LatticeExprNode &expr)
Numerical 1-argument functions.

The following will calculate the value and the derivative for A=2; f=3; x=0.1;

// The function objects for value, and for value + derivative
Sinusoid<Double> soid1(2.0, 3.0);
typedef AutoDiff<Double> Adif;
Sinusoid<Adif> soid2(Adif(2,2,0), Adif(3,2,1));
cout << "Value: " << soid1(0.1) << endl;
cout << "(val, deriv): " << soid2(Adif(0.1)) << endl;

A shorter version, where all parameter handling is done at user level could be:

//# Sinusoid.h
#include <casacore/casa/aips.h>
#include <casacore/scimath/Functionals/Function.h>
#include <casacore/casa/BasicSL/Constants.h>
#include <casacore/casa/BasicMath/Math.h>
template<class T> class Sinusoid : public Function<T> {
public:
enum { AMPL=0, FREQ };
Sinusoid() : Function<T>(2){param_p[AMPL] T(1);param_p[FREQ]=T(1);}
virtual ~Sinusoid() {}
virtual uInt ndim() const { return 2; }
virtual T eval(Function<T>::FunctionArg x) const {
return param_p[AMPL]*sin(T(C::_2pi)*param_p[FREQ]*x[0]); }
virtual Function<T> *clone() const { return new Sinusoid<T>param_p; }
};

The following will calculate the value and the derivative for A=2; f=3; x=0.1;

// The function objects for value, and for value + derivative
typedef AutoDiff<Double> Adif;
typedef Function<Double> FD;
typedef Function<AutoDiff<Double> > FAdif
Sinusoid<Double> soid1;
Sinusoid<Adif> soid2;
soid1[FD::AMPL] = 2; soid1[FD::FREQ] = 3;
soid2[FAdif::AMPL] = Adif(2,2,0);
soid2[FAdif::FREQ] = Adif(3,2,1);
cout << "Value: " << soid1(0.1) << endl;
cout << "(val, deriv): " << soid2(Adif(0.1)) << endl;

Motivation

A function of more than one variable was required for a function which represents the sky brightness. Adjustable parameters were required for non-linear least squares fitting.

Template Type Argument Requirements (T)

To Do

Definition at line 200 of file Function.h.

Member Typedef Documentation

◆ ArgType

template<class T , class U = T>
typedef FunctionTraits<T>::ArgType casacore::Function< T, U >::ArgType

Definition at line 206 of file Function.h.

◆ FunctionArg

template<class T , class U = T>
typedef const ArgType* casacore::Function< T, U >::FunctionArg

Definition at line 207 of file Function.h.

Constructor & Destructor Documentation

◆ Function() [1/5]

template<class T , class U = T>
casacore::Function< T, U >::Function ( )
inline

Constructors.

Definition at line 212 of file Function.h.

◆ Function() [2/5]

template<class T , class U = T>
casacore::Function< T, U >::Function ( const uInt  n)
inlineexplicit

Definition at line 213 of file Function.h.

◆ Function() [3/5]

template<class T , class U = T>
casacore::Function< T, U >::Function ( const Vector< T > &  in)
inlineexplicit

Definition at line 215 of file Function.h.

◆ Function() [4/5]

template<class T , class U = T>
casacore::Function< T, U >::Function ( const FunctionParam< T > &  other)
inline

Definition at line 217 of file Function.h.

◆ Function() [5/5]

template<class T , class U = T>
template<class W , class X >
casacore::Function< T, U >::Function ( const Function< W, X > &  other)
inline

Definition at line 220 of file Function.h.

◆ ~Function()

template<class T , class U = T>
virtual casacore::Function< T, U >::~Function ( )
inlinevirtual

Destructor.

Definition at line 225 of file Function.h.

Member Function Documentation

◆ argp()

template<class T , class U = T>
const Vector<ArgType>& casacore::Function< T, U >::argp ( ) const
inline

Get arg_p and parset_p.

Necessary for reasons of protection in the copying of non-conforming Functions.

Definition at line 278 of file Function.h.

References casacore::Function< T, U >::arg_p.

◆ clone()

template<class T , class U = T>
virtual Function<T,U>* casacore::Function< T, U >::clone ( ) const
pure virtual

Return a copy of this object from the heap.

The caller is responsible for deleting this pointer. The cloneAD will return a clone with an AutoDef<T>; the cloneNonAD a clone with <T>. An AipsError will be thrown if the cloneAD() or cloneNonAD() is not implemented for a specific function.

Implemented in casacore::UnaryFunction< T >, casacore::SPolynomial< T >, casacore::Sinusoid1D_PS< AutoDiff< T > >, casacore::Sinusoid1D< T >, casacore::SincFunction< T >, casacore::SimButterworthBandpass< T >, casacore::PowerLogarithmicPolynomial_PS< AutoDiff< T > >, casacore::PowerLogarithmicPolynomial< T >, casacore::Polynomial_PS< AutoDiff< T > >, casacore::Polynomial< T >, casacore::Polynomial< Double >, casacore::PoissonFunction_PS< AutoDiff< T > >, casacore::PoissonFunction< T >, casacore::OddPolynomial_PS< AutoDiff< T > >, casacore::OddPolynomial< T >, casacore::MarshButterworthBandpass< T >, casacore::MarshallableChebyshev< T >, casacore::Lorentzian1D_PS< AutoDiff< T > >, casacore::Lorentzian1D< T >, casacore::KaiserBFunction< T >, casacore::Interpolate1D< Domain, Range >, casacore::Interpolate1D< Double, Double >, casacore::HyperPlane_PS< AutoDiff< T > >, casacore::HyperPlane< T >, casacore::GNoiseFunction< T >, casacore::GaussianND< T >, casacore::Gaussian3D_PS< AutoDiff< T > >, casacore::Gaussian3D< T >, casacore::Gaussian2D_PS< AutoDiff< T > >, casacore::Gaussian2D< T >, casacore::Gaussian1D_PS< AutoDiff< T > >, casacore::Gaussian1D< T >, casacore::FunctionWrapper< T >, casacore::EvenPolynomial_PS< AutoDiff< T > >, casacore::EvenPolynomial< T >, casacore::DiracDFunction< T >, casacore::ConstantND_PS< AutoDiff< T > >, casacore::ConstantND< T >, casacore::CompoundFunction_PS< AutoDiff< T > >, casacore::CompoundFunction< T >, casacore::CompoundFunction< casacore::AutoDiff< Double > >, casacore::CompiledFunction< T >, casacore::CombiFunction_PS< AutoDiff< T > >, casacore::CombiFunction< T >, and casacore::Chebyshev< T >.

◆ cloneAD()

template<class T , class U = T>
virtual Function<typename FunctionTraits<T>::DiffType>* casacore::Function< T, U >::cloneAD ( ) const
virtual

◆ cloneNonAD()

template<class T , class U = T>
virtual Function<typename FunctionTraits<T>::BaseType>* casacore::Function< T, U >::cloneNonAD ( ) const
virtual

◆ eval()

template<class T , class U = T>
virtual U casacore::Function< T, U >::eval ( FunctionArg  x) const
pure virtual

Evaluate the function object.

Referenced by casacore::Function< T, U >::operator()().

◆ getMode()

template<class T , class U = T>
virtual void casacore::Function< T, U >::getMode ( RecordInterface mode) const
virtual

◆ hasMode()

template<class T , class U = T>
virtual Bool casacore::Function< T, U >::hasMode ( ) const
virtual

return True if the implementing function supports a mode.

The default implementation returns False.

Reimplemented in casacore::SimButterworthBandpass< T >, and casacore::ChebyshevParamModeImpl< T >.

◆ lockParam()

template<class T , class U = T>
void casacore::Function< T, U >::lockParam ( )
inline

Compiler cannot always find the correct 'const' version of parameter access.

In cases where this would lead to excessive overheads in moving parameters around (like in CompoundFunction) the parameter changing can be set to be locked, and no changes are assumed.

Definition at line 287 of file Function.h.

References casacore::Function< T, U >::locked_p, and casacore::True.

◆ mask() [1/2]

template<class T , class U = T>
Bool& casacore::Function< T, U >::mask ( const uInt  n)
inline

Manipulate the mask associated with the nth parameter (e.g.

to indicate whether the parameter is adjustable or nonadjustable). Note: no index check.

Definition at line 266 of file Function.h.

References casacore::Function< T, U >::locked_p, casacore::Function< T, U >::param_p, and casacore::Function< T, U >::parset_p.

◆ mask() [2/2]

template<class T , class U = T>
const Bool& casacore::Function< T, U >::mask ( const uInt  n) const
inline

Definition at line 268 of file Function.h.

References casacore::Function< T, U >::param_p.

◆ name()

template<class T , class U = T>
virtual const String& casacore::Function< T, U >::name ( ) const
virtual

Specify the name associated with the function (default will be unknown)

Reimplemented in casacore::WrapperParam< T >, casacore::UnaryParam< T >, casacore::SPolynomialParam< T >, casacore::Sinusoid1DParam< T >, casacore::Sinusoid1DParam< AutoDiff< T > >, casacore::SincParam< T >, casacore::PowerLogarithmicPolynomialParam< T >, casacore::PowerLogarithmicPolynomialParam< AutoDiff< T > >, casacore::PolynomialParam< T >, casacore::PolynomialParam< AutoDiff< T > >, casacore::PoissonParam< T >, casacore::PoissonParam< AutoDiff< T > >, casacore::OddPolynomialParam< T >, casacore::OddPolynomialParam< AutoDiff< T > >, casacore::Lorentzian1DParam< T >, casacore::Lorentzian1DParam< AutoDiff< T > >, casacore::KaiserBParam< T >, casacore::Interpolate1D< Domain, Range >, casacore::Interpolate1D< Double, Double >, casacore::HyperPlaneParam< T >, casacore::HyperPlaneParam< AutoDiff< T > >, casacore::GNoiseParam< T >, casacore::GaussianNDParam< T >, casacore::Gaussian3DParam< Type >, casacore::Gaussian3DParam< AutoDiff< T > >, casacore::Gaussian3DParam< T >, casacore::Gaussian2DParam< T >, casacore::Gaussian2DParam< AutoDiff< T > >, casacore::Gaussian1DParam< T >, casacore::Gaussian1DParam< AutoDiff< T > >, casacore::EvenPolynomialParam< T >, casacore::EvenPolynomialParam< AutoDiff< T > >, casacore::DiracDParam< T >, casacore::ConstantNDParam< T >, casacore::ConstantNDParam< AutoDiff< T > >, casacore::CompoundParam< T >, casacore::CompoundParam< AutoDiff< T > >, casacore::CompiledParam< T >, casacore::CombiParam< T >, casacore::CombiParam< AutoDiff< T > >, casacore::ChebyshevParam< T >, casacore::ChebyshevParam< AutoDiff< T > >, and casacore::ChebyshevParam< AutoDiffA< T > >.

◆ ndim()

template<class T , class U = T>
virtual uInt casacore::Function< T, U >::ndim ( ) const
pure virtual

◆ nparameters()

template<class T , class U = T>
uInt casacore::Function< T, U >::nparameters ( ) const
inline

◆ operator()() [1/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( ) const
inlinevirtual

Evaluate this function object at xor at x, y.

The length of x must be greater than or equal to ndim().

Definition at line 246 of file Function.h.

References DebugAssert, casacore::Function< T, U >::eval(), and casacore::Function< T, U >::ndim().

◆ operator()() [2/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( const ArgType x) const
inlinevirtual

◆ operator()() [3/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( const ArgType x,
const ArgType y 
) const
virtual

◆ operator()() [4/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( const ArgType x,
const ArgType y,
const ArgType z 
) const
virtual

◆ operator()() [5/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( const Vector< ArgType > &  x) const
virtual

◆ operator()() [6/6]

template<class T , class U = T>
virtual U casacore::Function< T, U >::operator() ( FunctionArg  x) const
inlinevirtual

Definition at line 251 of file Function.h.

References casacore::Function< T, U >::eval().

◆ operator[]() [1/2]

template<class T , class U = T>
T& casacore::Function< T, U >::operator[] ( const uInt  n)
inline

Manipulate the nth parameter (0-based) with no index check.

Definition at line 238 of file Function.h.

References casacore::Function< T, U >::locked_p, casacore::Function< T, U >::param_p, and casacore::Function< T, U >::parset_p.

◆ operator[]() [2/2]

template<class T , class U = T>
const T& casacore::Function< T, U >::operator[] ( const uInt  n) const
inline

Definition at line 240 of file Function.h.

References casacore::Function< T, U >::param_p.

◆ parameters() [1/2]

template<class T , class U = T>
FunctionParam<T>& casacore::Function< T, U >::parameters ( )
inline

◆ parameters() [2/2]

template<class T , class U = T>
const FunctionParam<T>& casacore::Function< T, U >::parameters ( ) const
inline

Return the parameter interface.

Definition at line 272 of file Function.h.

References casacore::Function< T, U >::param_p.

◆ parsetp()

template<class T , class U = T>
Bool casacore::Function< T, U >::parsetp ( ) const
inline

Definition at line 279 of file Function.h.

References casacore::Function< T, U >::parset_p.

◆ print()

template<class T , class U = T>
ostream& casacore::Function< T, U >::print ( ostream &  os) const
inline

Print the function (i.e.

the parameters)

Definition at line 315 of file Function.h.

References casacore::Function< T, U >::param_p.

Referenced by casacore::operator<<().

◆ setMode()

template<class T , class U = T>
virtual void casacore::Function< T, U >::setMode ( const RecordInterface mode)
virtual

get/set the function mode.

These provide an interface to function-specific configuration or state that controls how the function calculates its values but otherwise does not qualify as a parameter. Some part of the state, for example, might have a type different from that of T. The state is passed as fields of a record, mode–the names, types and values of which are specific to the implementing function and should be documented in the implementing class. It is recommended that all possible inputs passed to this function via setMode() be considered optional such that if the record omits a legal field, that part of the state is left unchanged. Fields not recognized by the implementing class should be ignored. An exception should be thrown if a recognized field contains illegal data. The default implementations for both getMode() and setMode() ignore the input record.

Reimplemented in casacore::SimButterworthBandpass< T >, casacore::ChebyshevParamModeImpl_PSA< AutoDiffA< T > >, casacore::ChebyshevParamModeImpl_PS< AutoDiff< T > >, and casacore::ChebyshevParamModeImpl< T >.

◆ unlockParam()

template<class T , class U = T>
void casacore::Function< T, U >::unlockParam ( )
inline

Definition at line 288 of file Function.h.

References casacore::False, and casacore::Function< T, U >::locked_p.

Member Data Documentation

◆ arg_p

template<class T , class U = T>
Vector<ArgType> casacore::Function< T, U >::arg_p
mutableprotected

Aid for non-contiguous argument storage.

Definition at line 334 of file Function.h.

Referenced by casacore::Function< T, U >::argp().

◆ locked_p

template<class T , class U = T>
Bool casacore::Function< T, U >::locked_p
mutableprotected

Indicate that parameters are expected to be locked from changing.

Definition at line 338 of file Function.h.

Referenced by casacore::Function< T, U >::lockParam(), casacore::Function< T, U >::mask(), casacore::Function< T, U >::operator[](), and casacore::Function< T, U >::unlockParam().

◆ param_p

template<class T , class U = T>
FunctionParam<T> casacore::Function< T, U >::param_p
protected

The parameters and masks.

Definition at line 332 of file Function.h.

Referenced by casacore::SPolynomialParam< T >::coefficient(), casacore::Gaussian2DParam< T >::height(), casacore::GaussianNDParam< T >::height(), casacore::PoissonParam< T >::height(), casacore::PoissonParam< T >::lambda(), casacore::Function< T, U >::mask(), casacore::HyperPlaneParam< T >::ndim(), casacore::Function< T, U >::nparameters(), casacore::ConstantNDParam< T >::operator!=(), casacore::EvenPolynomialParam< T >::operator!=(), casacore::HyperPlaneParam< T >::operator!=(), casacore::OddPolynomialParam< T >::operator!=(), casacore::PolynomialParam< T >::operator!=(), casacore::PowerLogarithmicPolynomialParam< T >::operator!=(), casacore::SPolynomialParam< T >::operator!=(), casacore::ConstantNDParam< T >::operator==(), casacore::EvenPolynomialParam< T >::operator==(), casacore::HyperPlaneParam< T >::operator==(), casacore::OddPolynomialParam< T >::operator==(), casacore::PolynomialParam< T >::operator==(), casacore::PowerLogarithmicPolynomialParam< T >::operator==(), casacore::SPolynomialParam< T >::operator==(), casacore::Function< T, U >::operator[](), casacore::SPolynomialParam< T >::order(), casacore::Function< T, U >::parameters(), casacore::Function< T, U >::print(), casacore::SPolynomialParam< T >::setCoefficient(), casacore::Gaussian2DParam< T >::setHeight(), casacore::GaussianNDParam< T >::setHeight(), casacore::PoissonParam< T >::setHeight(), casacore::PoissonParam< T >::setLambda(), casacore::Gaussian2DParam< T >::setXcenter(), casacore::Gaussian2DParam< T >::setYcenter(), casacore::Gaussian2DParam< T >::xCenter(), and casacore::Gaussian2DParam< T >::yCenter().

◆ parset_p

template<class T , class U = T>
Bool casacore::Function< T, U >::parset_p
mutableprotected

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