lsst::geom::polynomials::Function2d< Basis_ > Class Template Reference

A 2-d function defined by a series expansion and its coefficients. More...

#include <Function2d.h>

Public Types
using	iterator = double *
using	const_iterator = double const *
using	Basis = Basis_
	The basis type used by this function.
using	Workspace = typename Basis::Workspace
	Type returned by makeWorkspace().

Public Member Functions
	Function2d (Basis const &basis)
	Construct with zero-valued coefficients.
	Function2d (Basis const &basis, Eigen::VectorXd const &coefficients)
	Construct with coefficients from an Eigen object.
template<typename Iterator >
	Function2d (Basis const &basis, Iterator first, Iterator last)
	Construct by copying coefficients from an STL iterator range.
	Function2d (Function2d const &)=default
	Default copy constructor.
	Function2d (Function2d &&)=default
	Default move constructor.
Function2d &	operator= (Function2d const &)=default
	Default copy assignment.
Function2d &	operator= (Function2d &&)=default
	Default move assignment.
iterator	begin ()
	Iterators over coefficients.
iterator	end ()
const_iterator	cbegin () const
const_iterator	cend () const
const_iterator	begin () const
const_iterator	end () const
Basis const &	getBasis () const
	Return the associated Basis2d object.
std::size_t	size () const
	Return the number of coefficients.
Workspace	makeWorkspace () const
	Allocate workspace that can be passed to operator() to avoid repeated memory allocations.
double	operator() (geom::Point2D const &point, SumMode mode=SumMode::FAST) const
	Evaluate the function at the given point.
double	operator() (geom::Point2D const &point, Workspace &workspace, SumMode mode=SumMode::FAST) const
	Evaluate the function at the given point.
double &	operator[] (std::size_t n)
	Return the coefficient associated with the nth basis function.
double const &	operator[] (std::size_t n) const
auto	getCoefficients ()
	Return the coefficient vector as an Eigen matrix-like object.
auto	getCoefficients () const
Function2d< typename Basis::Scaled >	scaled (Scaling2d const &scaling) const
	Return a new function that applies the given scaling to all points before evaluation.

Detailed Description

template<typename Basis_>
class lsst::geom::polynomials::Function2d< Basis_ >

A 2-d function defined by a series expansion and its coefficients.

A Function1d combines a Basis2d that defines basis functions \(B_{n}(x, y)\) with a flattened vector of associated coefficients \(a_{n}\). The basis defines the order of coefficients. Evaluating the function computes

\[ \sum_{n}^{n \le N} a_{n} B_{n}(x, y) \]

Definition at line 42 of file Function2d.h.

Member Typedef Documentation

Basis

template<typename Basis_ >

using lsst::geom::polynomials::Function2d< Basis_ >::Basis = Basis_

The basis type used by this function.

Definition at line 49 of file Function2d.h.

const_iterator

template<typename Basis_ >

using lsst::geom::polynomials::Function2d< Basis_ >::const_iterator = double const *

Definition at line 46 of file Function2d.h.

iterator

template<typename Basis_ >

using lsst::geom::polynomials::Function2d< Basis_ >::iterator = double *

Definition at line 45 of file Function2d.h.

Workspace

template<typename Basis_ >

using lsst::geom::polynomials::Function2d< Basis_ >::Workspace = typename Basis::Workspace

Type returned by makeWorkspace().

Definition at line 52 of file Function2d.h.

Constructor & Destructor Documentation

Function2d() [1/5]

template<typename Basis_ >

lsst::geom::polynomials::Function2d< Basis_ >::Function2d ( Basis const & basis )

inlineexplicit

Construct with zero-valued coefficients.

Definition at line 55 of file Function2d.h.

                                             :
        _basis(basis),
        _coefficients(Eigen::VectorXd::Zero(basis.size()))
    {}

Function2d() [2/5]

template<typename Basis_ >

lsst::geom::polynomials::Function2d< Basis_ >::Function2d ( Basis const & basis, Eigen::VectorXd const & coefficients )

inlineexplicit

Construct with coefficients from an Eigen object.

Definition at line 61 of file Function2d.h.

                                                                                 :
        _basis(basis),
        _coefficients(coefficients)
    {
        assert(basis.size() == static_cast<std::size_t>(_coefficients.size()));
    }

Function2d() [3/5]

template<typename Basis_ >

template<typename Iterator >

lsst::geom::polynomials::Function2d< Basis_ >::Function2d ( Basis const & basis, Iterator first, Iterator last )

inlineexplicit

Construct by copying coefficients from an STL iterator range.

Definition at line 70 of file Function2d.h.

                                                                            :
        _basis(basis),
        _coefficients(basis.size())
    {
        assert(std::distance(first, last) == static_cast<std::ptrdiff_t>(basis.size()));
        std::copy(first, last, &_coefficients[0]);
    }

Function2d() [4/5]

template<typename Basis_ >

lsst::geom::polynomials::Function2d< Basis_ >::Function2d ( Function2d< Basis_ > const & )

default

Default copy constructor.

Function2d() [5/5]

template<typename Basis_ >

lsst::geom::polynomials::Function2d< Basis_ >::Function2d ( Function2d< Basis_ > && )

default

Default move constructor.

Member Function Documentation

begin() [1/2]

template<typename Basis_ >

iterator lsst::geom::polynomials::Function2d< Basis_ >::begin ( )

inline

Iterators over coefficients.

Definition at line 92 of file Function2d.h.

{ return _coefficients.data(); }

begin() [2/2]

template<typename Basis_ >

const_iterator lsst::geom::polynomials::Function2d< Basis_ >::begin ( ) const

inline

Definition at line 96 of file Function2d.h.

{ return _coefficients.data(); }

cbegin()

template<typename Basis_ >

const_iterator lsst::geom::polynomials::Function2d< Basis_ >::cbegin ( ) const

inline

Definition at line 94 of file Function2d.h.

{ return _coefficients.data(); }

cend()

template<typename Basis_ >

const_iterator lsst::geom::polynomials::Function2d< Basis_ >::cend ( ) const

inline

Definition at line 95 of file Function2d.h.

{ return begin() + size(); }

end() [1/2]

template<typename Basis_ >

iterator lsst::geom::polynomials::Function2d< Basis_ >::end ( )

inline

Definition at line 93 of file Function2d.h.

{ return begin() + size(); }

end() [2/2]

template<typename Basis_ >

const_iterator lsst::geom::polynomials::Function2d< Basis_ >::end ( ) const

inline

Definition at line 97 of file Function2d.h.

{ return begin() + size(); }

getBasis()

template<typename Basis_ >

Basis const & lsst::geom::polynomials::Function2d< Basis_ >::getBasis ( ) const

inline

Return the associated Basis2d object.

Definition at line 101 of file Function2d.h.

{ return _basis; }

getCoefficients() [1/2]

template<typename Basis_ >

auto lsst::geom::polynomials::Function2d< Basis_ >::getCoefficients ( )

inline

Return the coefficient vector as an Eigen matrix-like object.

The exact type of the returned object is unspecified, but it is guaranteed to be a view.

Definition at line 136 of file Function2d.h.

                           {
        // Return a block view to ensure the caller only modify the values, not the size.
        return _coefficients.head(size());
    }

getCoefficients() [2/2]

template<typename Basis_ >

auto lsst::geom::polynomials::Function2d< Basis_ >::getCoefficients ( ) const

inline

Definition at line 140 of file Function2d.h.

{ return _coefficients.head(size()); }

makeWorkspace()

template<typename Basis_ >

Workspace lsst::geom::polynomials::Function2d< Basis_ >::makeWorkspace ( ) const

inline

Allocate workspace that can be passed to operator() to avoid repeated memory allocations.

Definition at line 107 of file Function2d.h.

{ return _basis.makeWorkspace(); }

operator()() [1/2]

template<typename Basis_ >

double lsst::geom::polynomials::Function2d< Basis_ >::operator() ( geom::Point2D const & point, SumMode mode = SumMode::FAST ) const

inline

Evaluate the function at the given point.

Definition at line 110 of file Function2d.h.

                                                                                 {
        return _basis.sumWith(point, _coefficients, mode);
    }

operator()() [2/2]

template<typename Basis_ >

double lsst::geom::polynomials::Function2d< Basis_ >::operator() ( geom::Point2D const & point, Workspace & workspace, SumMode mode = SumMode::FAST ) const

inline

Evaluate the function at the given point.

Definition at line 115 of file Function2d.h.

                                                                                                        {
        return _basis.sumWith(point, _coefficients, workspace, mode);
    }

operator=() [1/2]

template<typename Basis_ >

Function2d & lsst::geom::polynomials::Function2d< Basis_ >::operator= ( Function2d< Basis_ > && )

default

Default move assignment.

operator=() [2/2]

template<typename Basis_ >

Function2d & lsst::geom::polynomials::Function2d< Basis_ >::operator= ( Function2d< Basis_ > const & )

default

Default copy assignment.

operator[]() [1/2]

template<typename Basis_ >

double & lsst::geom::polynomials::Function2d< Basis_ >::operator[] ( std::size_t n )

inline

Return the coefficient associated with the nth basis function.

Caller is responsible for ensuring that the given index is valid.

Definition at line 125 of file Function2d.h.

{ return  begin()[n]; }

operator[]() [2/2]

template<typename Basis_ >

double const & lsst::geom::polynomials::Function2d< Basis_ >::operator[] ( std::size_t n ) const

inline

Definition at line 126 of file Function2d.h.

{ return begin()[n]; }

scaled()

template<typename Basis_ >

Function2d< typename Basis::Scaled > lsst::geom::polynomials::Function2d< Basis_ >::scaled ( Scaling2d const & scaling ) const

inline

Return a new function that applies the given scaling to all points before evaluation.

Definition at line 144 of file Function2d.h.

                                                                             {
        return Function2d<typename Basis::Scaled>(getBasis().scaled(scaling), _coefficients);
    }

size()

template<typename Basis_ >

std::size_t lsst::geom::polynomials::Function2d< Basis_ >::size ( ) const

inline

Return the number of coefficients.

Definition at line 104 of file Function2d.h.

{ return _basis.size(); }

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/geom/ga1e77700b3+15fc3df1f7/include/lsst/geom/polynomials/Function2d.h