casacore::AutoDiffX< T > Class Template Reference

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#include <AutoDiffX.h>

Public Member Functions
	AutoDiffX ()
	Construct a constant with a value of zero. More...
	AutoDiffX (const T &v)
	Construct a constant with a value of v. More...
	AutoDiffX (const T &v, const uInt ndiffs, const uInt n)
	A function f(x0,x1,...,xn,...) with a value of v. More...
	AutoDiffX (const T &v, const uInt ndiffs)
	A function f(x0,x1,...,xn,...) with a value of v. More...
	AutoDiffX (const AutoDiff< T > &other)
	Construct one from another. More...
	AutoDiffX (const T &v, const Vector< T > &derivs)
	Construct a function f(x0,x1,...,xn) of a value v and a vector of derivatives derivs(0) = df/dx0, derivs(1) = df/dx1,... More...
	~AutoDiffX ()
AutoDiffX< T > &	operator= (const T &v)
	Assignment operator. More...
AutoDiffX< T > &	operator= (const AutoDiff< T > &other)
	Assign one to another. More...
Public Member Functions inherited from casacore::AutoDiff< T >
	AutoDiff ()
	Construct a constant with a value of zero. More...
	AutoDiff (const T &v)
	Construct a constant with a value of v. More...
	AutoDiff (const T &v, const uInt ndiffs, const uInt n)
	A function f(x0,x1,...,xn,...) with a value of v. More...
	AutoDiff (const T &v, const uInt ndiffs)
	A function f(x0,x1,...,xn,...) with a value of v. More...
	AutoDiff (const AutoDiff< T > &other)
	Construct one from another. More...
	AutoDiff (const T &v, const Vector< T > &derivs)
	Construct a function f(x0,x1,...,xn) of a value v and a vector of derivatives derivs(0) = df/dx0, derivs(1) = df/dx1,... More...
	~AutoDiff ()
AutoDiff< T > &	operator= (const T &v)
	Assignment operator. More...
AutoDiff< T > &	operator= (const AutoDiff< T > &other)
	Assign one to another. More...
void	operator*= (const AutoDiff< T > &other)
	In-place mathematical operators. More...
void	operator/= (const AutoDiff< T > &other)
void	operator+= (const AutoDiff< T > &other)
void	operator-= (const AutoDiff< T > &other)
void	operator*= (const T other)
void	operator/= (const T other)
void	operator+= (const T other)
void	operator-= (const T other)
T &	value ()
	Returns the value of the function. More...
const T &	value () const
const Vector< T > &	derivatives () const
	Returns a vector of the derivatives of an AutoDiff. More...
Vector< T > &	derivatives ()
void	derivatives (Vector< T > &res) const
T &	derivative (uInt which)
	Returns a specific derivative. More...
const T &	derivative (uInt which) const
T &	deriv (uInt which)
const T &	deriv (uInt which) const
uInt	nDerivatives () const
	Return total number of derivatives. More...
Bool	isConstant () const
	Is it a constant, i.e., with zero derivatives? More...

Additional Inherited Members
Public Types inherited from casacore::AutoDiff< T >
typedef T	value_type
typedef value_type &	reference
typedef const value_type &	const_reference
typedef value_type *	iterator
typedef const value_type *	const_iterator

Detailed Description

template<class T>
class casacore::AutoDiffX< T >

Class that computes partial derivatives by automatic differentiation.

Intended use:

Public interface

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Test programs:

tAutoDiff

Demo programs:

dAutoDiff

Prerequisite

• AutoDiff

Etymology

Class that computes partial derivatives by automatic differentiation, thus AutoDiff.

Synopsis

AutoDiffX is an AutoDiff. It is used to be able to distinguish between two template incarnations; e.g. to have one or more specializations, in addition to the general template version.

Example

See for an extensive example the demo program dAutoDiff. It is based on the example given in the AutoDiff class, and shows how to have both an automatic and a specific version of a function object.

// The function, with fixed parameters a,b:
template <class T> class f {
public:
T operator()(const T& x) { return a_p*a_p*a_p*b_p*b_p*x; }
void set(const T& a, const T& b) { a_p = a; b_p = b; }
private:
T a_p;
T b_p;
};
// The specialized function
template <> class f<AutoDiffX<Double> > {
public:
T operator()(const T& x) { return a_p*a_p*a_p*b_p*b_p*x; }
void set(const T& a, const T& b) { a_p = a; b_p = b; }
private:
T a_p;
T b_p;
};
// Call it with different template arguments:
AutoDiff<Double> a1(2,2,0), b1(3,2,1), x1(7);
f<AutoDiff<Double> > f1; f1.set(a1, b1);
cout << "Diff a,b:   " << f1(x1) << endl;
 
f<AutoDiffX<Double> > f12; f12.set(a1, b1);
cout << "Same....:   " << f12(x1) << endl;
 
// Result will be:
// Diff a,b:  (504, [756, 336])
// Same....:  (504, [756, 336])
 
// It needed the template instantiations definitions:
template class f<AutoDiff<Double> >;

Motivation

The class was created to enable separate calculations of the same function.

Template Type Argument Requirements (T)

• any class that has the standard mathematical and comparisons defined

To Do

• Nothing I know

Definition at line 119 of file AutoDiffX.h.

Constructor & Destructor Documentation

AutoDiffX() [1/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( )

inline

Construct a constant with a value of zero.

Zero derivatives.

Definition at line 123 of file AutoDiffX.h.

AutoDiffX() [2/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( const T &  v )

inline

Construct a constant with a value of v.

Zero derivatives.

Definition at line 126 of file AutoDiffX.h.

AutoDiffX() [3/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( const T &  v, const uInt  ndiffs, const uInt  n  )

inline

A function f(x0,x1,...,xn,...) with a value of v.

The total number of derivatives is ndiffs, the nth derivative is one, and all others are zero.

Definition at line 131 of file AutoDiffX.h.

AutoDiffX() [4/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( const T &  v, const uInt  ndiffs  )

inline

A function f(x0,x1,...,xn,...) with a value of v.

The total number of derivatives is ndiffs. All derivatives are zero.

Definition at line 137 of file AutoDiffX.h.

AutoDiffX() [5/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( const AutoDiff< T > &  other )

inline

Construct one from another.

Definition at line 140 of file AutoDiffX.h.

AutoDiffX() [6/6]

template<class T >

casacore::AutoDiffX< T >::AutoDiffX ( const T &  v, const Vector< T > &  derivs  )

inline

Construct a function f(x0,x1,...,xn) of a value v and a vector of derivatives derivs(0) = df/dx0, derivs(1) = df/dx1,...

Definition at line 144 of file AutoDiffX.h.

~AutoDiffX()

template<class T >

casacore::AutoDiffX< T >::~AutoDiffX ( )

inline

Definition at line 146 of file AutoDiffX.h.

Member Function Documentation

operator=() [1/2]

template<class T >

AutoDiffX<T>& casacore::AutoDiffX< T >::operator= ( const AutoDiff< T > &  other )

inline

Assign one to another.

Definition at line 156 of file AutoDiffX.h.

References casacore::AutoDiff< T >::operator=().

operator=() [2/2]

template<class T >

AutoDiffX<T>& casacore::AutoDiffX< T >::operator= ( const T &  v )

inline

Assignment operator.

Assign a constant to variable. All derivatives are zero.

Definition at line 150 of file AutoDiffX.h.

References casacore::AutoDiff< T >::operator=().

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

• scimath/Mathematics/AutoDiffX.h