casa::CombiFunction< T > Class Template Reference

Form a linear combination of function objects. More...

#include <CombiFunction.h>

Inheritance diagram for casa::CombiFunction< T >:

List of all members.

Public Member Functions
	CombiFunction ()
	The default constructor -- no functions, no parameters, nothing, the function operator returns a 0.
	CombiFunction (const CombiFunction< T > &other)
	Make this object a (deep) copy of other.
	CombiFunction (const CombiFunction< T > &other, Bool)
template<class W >
	CombiFunction (const CombiFunction< W > &other)
template<class W >
	CombiFunction (const CombiFunction< W > &other, Bool)
CombiFunction< T > &	operator= (const CombiFunction< T > &other)
	Make this object a (deep) copy of other.
virtual	~CombiFunction ()
	Destructor.
virtual T	eval (typename Function< T >::FunctionArg x) const
	Evaluate the function at x.
virtual Function< T > *	clone () const
	Return a copy of this object from the heap.
virtual Function< typename FunctionTraits< T >::DiffType > *	cloneAD () const
virtual Function< typename FunctionTraits< T >::BaseType > *	cloneNonAD () const

---

Detailed Description

template<class T>
class casa::CombiFunction< T >

Form a linear combination of function objects.

Intended use:

Public interface

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Test programs:

tCombiFunction

Prerequisite

• Function class

Synopsis

Given N function objects, the class describes a linear combination of the form:

    f(x) = a(0)*f(0)(x) + a(1)*f(1)(x) + ... + a(N-1)*f(N-1)(x)

where a = {a(n)} are parameters. If the combi function is used in a functional fitting process (see LinearFit ) these parameters canm be solved for. In all aspects they behave as FunctionParam values.

Member functions are added with the addFunction() method.

Tip: Check CompoundFunction class for a combination of functions behaving as one object;

Example

In the following example a second order polynomial is built from 3 separate polynomials.

    Polynomial<Double> constant(0); 
    Polynomial<Double> linear(1); 
    Polynomial<Double> square(2);
    
    constant.setCoefficient(0, 1.0);   // 1
    linear.setCoefficient(1, 1.0);     // x
    square[2] = 1.0;     // x^2
    
    CombiFunction<Double> combination;
    
    // form function, e0 + e1*x + e2*x^2
    combination.addFunction(constant);
    combination.addFunction(linear);
    combination.addFunction(square);

Template Type Argument Requirements (T)

• T should have standard numerical operators and exp() function. Current implementation only tested for real types.
• To obtain derivatives, the derivatives should be defined.

Thrown Exceptions

• AipsError in debug mode if incorrect function index

Motivation

This class was created to allow specialization of the evaluation in a simple way.

To Do

• Nothing I know of

Definition at line 114 of file CombiFunction.h.

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Constructor & Destructor Documentation

template<class T>

casa::CombiFunction< T >::CombiFunction

(

)

[inline]

The default constructor -- no functions, no parameters, nothing, the function operator returns a 0.

Definition at line 119 of file CombiFunction.h.

template<class T>

casa::CombiFunction< T >::CombiFunction

(

const CombiFunction< T > &

other

)

[inline]

Make this object a (deep) copy of other.

Definition at line 122 of file CombiFunction.h.

template<class T>

casa::CombiFunction< T >::CombiFunction	(	const CombiFunction< T > &	other,
		Bool
	)		[inline]

Definition at line 124 of file CombiFunction.h.

template<class T>

template<class W >

casa::CombiFunction< T >::CombiFunction

(

const CombiFunction< W > &

other

)

[inline]

Definition at line 127 of file CombiFunction.h.

template<class T>

template<class W >

casa::CombiFunction< T >::CombiFunction	(	const CombiFunction< W > &	other,
		Bool
	)		[inline]

Definition at line 129 of file CombiFunction.h.

template<class T>

virtual casa::CombiFunction< T >::~CombiFunction

(

)

[inline, virtual]

Destructor.

Definition at line 137 of file CombiFunction.h.

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Member Function Documentation

template<class T>

virtual Function<T>* casa::CombiFunction< T >::clone

(

)

const [inline, virtual]

Return a copy of this object from the heap.

The caller is responsible for deleting the pointer.

Implements casa::Function< T >.

Definition at line 147 of file CombiFunction.h.

template<class T>

virtual Function<typename FunctionTraits<T>::DiffType>* casa::CombiFunction< T >::cloneAD

(

)

const [inline, virtual]

Reimplemented from casa::Function< T >.

Definition at line 148 of file CombiFunction.h.

template<class T>

virtual Function<typename FunctionTraits<T>::BaseType>* casa::CombiFunction< T >::cloneNonAD

(

)

const [inline, virtual]

Reimplemented from casa::Function< T >.

Definition at line 150 of file CombiFunction.h.

References casa::True.

template<class T>

virtual T casa::CombiFunction< T >::eval

(

typename Function< T >::FunctionArg

x

)

const [virtual]

Evaluate the function at x.

template<class T>

CombiFunction<T>& casa::CombiFunction< T >::operator=

(

const CombiFunction< T > &

other

)

[inline]

Make this object a (deep) copy of other.

Definition at line 133 of file CombiFunction.h.

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

• casacore/scimath/Functionals/CombiFunction.h