casa::ConstantND< T > Class Template Reference

A constant function. More...

#include <ConstantND.h>

Inheritance diagram for casa::ConstantND< T >:

List of all members.

Public Member Functions
	ConstantND (const uInt m=0)
	Construct a constant in an a space of dimensionality m.
	ConstantND (const ConstantND< T > &other)
	Copy constructor/assignment (deep copy)
template<class W >
	ConstantND (const ConstantND< W > &other)
ConstantND< T > &	operator= (const ConstantND< T > &other)
virtual	~ConstantND ()
	Destructor.
virtual T	eval (typename Function< T >::FunctionArg x) const
	Evaluate the hyper plane function at (x0,x1,..,xm-1).
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::ConstantND< T >

A constant function.

Intended use:

Public interface

Review Status

Test programs:

tConstant

Prerequisite

• Function

Synopsis

This class represents a constant function in a space of arbitrary dimension f(x₀,x₁,..,x_m-1) = constant where x_i are independent arguments and m is the number of dimensions of the space.

Since the Constant is a Function, the derivatives can be obtained as well (and are in fact 0 of course).

The parameter interface (see FunctionParam class), is used to provide an interface to the Fitting classes.

This class is in general used implicitly by the Constant class only.

Example

    // form the constant function in 4-D space
     Constant<Double> constant(4); // 4-dim hyperplane
     constant.parameters()[0] = 22;
     // Evaluate at x0=5, x3=7
     Vector<Double> x(4);
     x=0; x[0]=5; x[3]=7;
     cout << "constant value: " << constant(x) << endl;
     constant value: 22

Template Type Argument Requirements (T)

• T should have standard numerical operators. Current implementation only tested for real types (and their AutoDiffs).

Thrown Exceptions

• Assertion in debug mode if attempt is made to address incorrect coefficients

Motivation

This class was created because HyperPlane does not support a constant offset and modifying that class really required an interface change (ie that the constant offset be at the beginning of the parameter vector and that the parameter vector increase by one) so rather than breaking any code that already used HyperPlane I simply made a trivial Constant class.

To Do

• Nothing I know of

Definition at line 108 of file ConstantND.h.

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Constructor & Destructor Documentation

template<class T>

casa::ConstantND< T >::ConstantND

(

const uInt

m = 0

)

[inline, explicit]

Construct a constant in an a space of dimensionality m.

By default, the constant value is initialised to zero, and m=0

Definition at line 114 of file ConstantND.h.

template<class T>

casa::ConstantND< T >::ConstantND

(

const ConstantND< T > &

other

)

[inline]

Copy constructor/assignment (deep copy)

Definition at line 117 of file ConstantND.h.

template<class T>

template<class W >

casa::ConstantND< T >::ConstantND

(

const ConstantND< W > &

other

)

[inline]

Definition at line 119 of file ConstantND.h.

template<class T>

virtual casa::ConstantND< T >::~ConstantND

(

)

[inline, virtual]

Destructor.

Definition at line 125 of file ConstantND.h.

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Member Function Documentation

template<class T>

virtual Function<T>* casa::ConstantND< 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 135 of file ConstantND.h.

template<class T>

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

(

)

const [inline, virtual]

Reimplemented from casa::Function< T >.

Definition at line 136 of file ConstantND.h.

template<class T>

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

(

)

const [inline, virtual]

Reimplemented from casa::Function< T >.

Definition at line 138 of file ConstantND.h.

template<class T>

virtual T casa::ConstantND< T >::eval

(

typename Function< T >::FunctionArg

x

)

const [virtual]

Evaluate the hyper plane function at (x₀,x₁,..,x_m-1).

template<class T>

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

(

const ConstantND< T > &

other

)

[inline]

Definition at line 120 of file ConstantND.h.

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

• casacore/scimath/Functionals/ConstantND.h