lsst::afw::math::Function< ReturnT > Class Template Reference

Basic Function class. More...

#include <Function.h>

Inheritance diagram for lsst::afw::math::Function< ReturnT >:

Public Member Functions
	Function (unsigned int nParams)
	Construct a Function given the number of function parameters. More...
	Function (std::vector< double > const &params)
	Construct a Function given the function parameters. More...
	Function (Function const &)=default
	Function (Function &&)=default
Function &	operator= (Function const &)=default
Function &	operator= (Function &&)=default
	~Function () noexcept override=default
unsigned int	getNParameters () const noexcept
	Return the number of function parameters. More...
virtual double	getParameter (unsigned int ind) const
	Get one function parameter without range checking. More...
std::vector< double > const &	getParameters () const noexcept
	Return all function parameters. More...
virtual bool	isLinearCombination () const noexcept
	Is the function a linear combination of its parameters? More...
void	setParameter (unsigned int ind, double newValue)
	Set one function parameter without range checking. More...
void	setParameters (std::vector< double > const &params)
	Set all function parameters. More...
virtual std::string	toString (std::string const &) const
	Return a string representation of the function. More...
void	writeFits (std::string const &fileName, std::string const &mode="w") const
	Write the object to a regular FITS file. More...
void	writeFits (fits::MemFileManager &manager, std::string const &mode="w") const
	Write the object to a FITS image in memory. More...
void	writeFits (fits::Fits &fitsfile) const
	Write the object to an already-open FITS object. More...
virtual bool	isPersistable () const noexcept
	Return true if this particular object can be persisted using afw::table::io. More...

Static Public Member Functions
static std::shared_ptr< Function< ReturnT > >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object. More...
static std::shared_ptr< Function< ReturnT > >	readFits (std::string const &fileName, int hdu=fits::DEFAULT_HDU)
	Read an object from a regular FITS file. More...
static std::shared_ptr< Function< ReturnT > >	readFits (fits::MemFileManager &manager, int hdu=fits::DEFAULT_HDU)
	Read an object from a FITS file in memory. More...
static std::shared_ptr< Function< ReturnT > >	dynamicCast (std::shared_ptr< Persistable > const &ptr)
	Dynamically cast a shared_ptr. More...

Protected Types
using	OutputArchiveHandle = io::OutputArchiveHandle

Protected Member Functions
std::string	getPythonModule () const override
	Return the fully-qualified Python module that should be imported to guarantee that its factory is registered. More...
	Function ()
virtual std::string	getPersistenceName () const
	Return the unique name used to persist this object and look up its factory. More...
virtual void	write (OutputArchiveHandle &handle) const
	Write the object to one or more catalogs. More...

Protected Attributes
std::vector< double >	_params
bool	_isCacheValid

Detailed Description

template<typename ReturnT>
class lsst::afw::math::Function< ReturnT >

Basic Function class.

Function objects are functions whose parameters may be read and changed using getParameters and setParameters. They were designed for use with the Kernel class.

These are simple functors with the restrictions that:

• Function arguments and parameters are double precision
• The return type is templated

To create a function for a particular equation, subclass Function or (much more likely) Function1 or Function2. Your subclass must:

• Have one or more constructors, all of which must initialize _params
• Define operator() with code to compute the function using this->_params or this->getParams() to reference the parameters
• If the function is a linear combination of parameters then override the function isLinearCombination.

If you wish to cache any information you may use the _isCacheValid flag; this is automatically set false whenever parameters are changed.

Design Notes: The reason these functions exist (rather than using a pre-existing function class, such as Functor in VisualWorkbench) is because the Kernel class requires function objects with a standard interface for setting and getting function parameters.

The reason isLinearCombination exists is to support refactoring LinearCombinationKernels.

Definition at line 83 of file Function.h.

Member Typedef Documentation

OutputArchiveHandle

using lsst::afw::table::io::Persistable::OutputArchiveHandle = io::OutputArchiveHandle

protectedinherited

Definition at line 108 of file Persistable.h.

Constructor & Destructor Documentation

Function() [1/5]

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::Function ( unsigned int  nParams )

inlineexplicit

Construct a Function given the number of function parameters.

The function parameters are initialized to 0.

Parameters

nParams

number of function parameters

Definition at line 91 of file Function.h.

            : _params(nParams), _isCacheValid(false) {}

Function() [2/5]

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::Function ( std::vector< double > const &  params )

inlineexplicit

Construct a Function given the function parameters.

Parameters

params

function parameters

Definition at line 97 of file Function.h.

            : _params(params), _isCacheValid(false) {}

Function() [3/5]

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::Function ( Function< ReturnT > const &  )

default

Function() [4/5]

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::Function ( Function< ReturnT > &&  )

default

~Function()

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::~Function ( )

overridedefaultnoexcept

Function() [5/5]

template<typename ReturnT >

lsst::afw::math::Function< ReturnT >::Function ( )

inlineexplicitprotected

Definition at line 191 of file Function.h.

: _params(0), _isCacheValid(false) {}

Member Function Documentation

dynamicCast()

template std::shared_ptr< meas::extensions::psfex::PsfexPsf > lsst::afw::table::io::PersistableFacade< Function< ReturnT > >::dynamicCast ( std::shared_ptr< Persistable > const &  ptr )

staticinherited

Dynamically cast a shared_ptr.

Dynamically cast a shared pointer and raise on failure.

You must provide an explicit template instantiation in the .cc file for each class that inherits from PersistableFacade. Designed to work around RTTI issues on macOS with hidden symbols;

Exceptions

lsst::pex::exceptions::LogicError

if the cast fails

param[in] ptr The pointer to be cast.

Returns

The cast pointer.

Exceptions

lsst::pex::exceptions::TypeError

If the dynamic cast fails.

Definition at line 218 of file Persistable.cc.

                                                                                        {
    auto result = std::dynamic_pointer_cast<T>(ptr);
    if (!result) {
        throw LSST_EXCEPT(pex::exceptions::TypeError, "Dynamic pointer cast failed");
    }
    return result;
}

getNParameters()

template<typename ReturnT >

unsigned int lsst::afw::math::Function< ReturnT >::getNParameters ( ) const

inlinenoexcept

Return the number of function parameters.

Returns

the number of function parameters

Definition at line 112 of file Function.h.

{ return _params.size(); }

getParameter()

template<typename ReturnT >

virtual double lsst::afw::math::Function< ReturnT >::getParameter ( unsigned int  ind ) const

inlinevirtual

Get one function parameter without range checking.

Returns

the specified function parameter

Parameters

ind	index of parameter

Definition at line 119 of file Function.h.

                  {
        return _params[ind];
    }

getParameters()

template<typename ReturnT >

std::vector<double> const& lsst::afw::math::Function< ReturnT >::getParameters ( ) const

inlinenoexcept

Return all function parameters.

Returns

the function parameters as a vector

Definition at line 129 of file Function.h.

{ return _params; }

getPersistenceName()

std::string lsst::afw::table::io::Persistable::getPersistenceName ( ) const

protectedvirtualinherited

Return the unique name used to persist this object and look up its factory.

Must be less than ArchiveIndexSchema::MAX_NAME_LENGTH characters.

Reimplemented in lsst::meas::modelfit::Mixture, lsst::meas::algorithms::WarpedPsf, lsst::meas::algorithms::SingleGaussianPsf, lsst::meas::algorithms::KernelPsf, lsst::meas::algorithms::DoubleGaussianPsf, lsst::meas::algorithms::CoaddPsf, lsst::meas::algorithms::CoaddBoundedField, lsst::afw::typehandling::StorableHelper< Base >, lsst::afw::math::WarpingControl, lsst::afw::math::NearestWarpingKernel, lsst::afw::math::BilinearWarpingKernel, lsst::afw::math::LanczosWarpingKernel, lsst::afw::math::TransformBoundedField, lsst::afw::math::ProductBoundedField, lsst::afw::math::PixelAreaBoundedField, lsst::afw::math::LinearCombinationKernel, lsst::afw::math::DeltaFunctionKernel, lsst::afw::math::AnalyticKernel, lsst::afw::math::FixedKernel, lsst::afw::math::Chebyshev1Function2< ReturnT >, lsst::afw::math::PolynomialFunction2< ReturnT >, lsst::afw::math::DoubleGaussianFunction2< ReturnT >, lsst::afw::math::GaussianFunction2< ReturnT >, lsst::afw::math::ChebyshevBoundedField, lsst::afw::image::VisitInfo, lsst::afw::image::PhotoCalib, lsst::afw::image::CoaddInputs, lsst::afw::geom::Transform< FromEndpoint, ToEndpoint >, lsst::afw::geom::Transform< afw::geom::Point2Endpoint, afw::geom::GenericEndpoint >, lsst::afw::geom::SkyWcs, lsst::afw::geom::polygon::Polygon, lsst::afw::detection::HeavyFootprint< ImagePixelT, MaskPixelT, VariancePixelT >, lsst::afw::detection::GaussianPsf, lsst::afw::detection::Footprint, lsst::afw::cameraGeom::DetectorCollection, and lsst::afw::image::FilterLabel.

Definition at line 34 of file Persistable.cc.

{ return std::string(); }

getPythonModule()

template<typename ReturnT >

std::string lsst::afw::math::Function< ReturnT >::getPythonModule ( ) const

inlineoverrideprotectedvirtual

Return the fully-qualified Python module that should be imported to guarantee that its factory is registered.

Must be less than ArchiveIndexSchema::MAX_MODULE_LENGTH characters.

Will be ignored if empty.

Reimplemented from lsst::afw::table::io::Persistable.

Definition at line 188 of file Function.h.

{ return "lsst.afw.math"; }

isLinearCombination()

template<typename ReturnT >

virtual bool lsst::afw::math::Function< ReturnT >::isLinearCombination ( ) const

inlinevirtualnoexcept

Is the function a linear combination of its parameters?

Returns

true if the function can be expressed as: sum over i of parameter_i * function_i(args)

Warning

: subclasses must override if true.

Reimplemented in lsst::afw::math::Chebyshev1Function1< ReturnT >, lsst::afw::math::PolynomialFunction1< ReturnT >, and lsst::afw::math::BasePolynomialFunction2< ReturnT >.

Definition at line 138 of file Function.h.

{ return false; }

isPersistable()

virtual bool lsst::afw::table::io::Persistable::isPersistable ( ) const

inlinevirtualnoexceptinherited

Return true if this particular object can be persisted using afw::table::io.

Reimplemented in lsst::meas::modelfit::Mixture, lsst::meas::extensions::psfex::PsfexPsf, lsst::meas::algorithms::WarpedPsf, lsst::meas::algorithms::SingleGaussianPsf, lsst::meas::algorithms::KernelPsf, lsst::meas::algorithms::DoubleGaussianPsf, lsst::meas::algorithms::CoaddPsf, lsst::meas::algorithms::CoaddBoundedField, lsst::afw::typehandling::StorableHelper< Base >, lsst::afw::math::WarpingControl, lsst::afw::math::NearestWarpingKernel, lsst::afw::math::BilinearWarpingKernel, lsst::afw::math::LanczosWarpingKernel, lsst::afw::math::TransformBoundedField, lsst::afw::math::ProductBoundedField, lsst::afw::math::PixelAreaBoundedField, lsst::afw::math::LinearCombinationKernel, lsst::afw::math::DeltaFunctionKernel, lsst::afw::math::AnalyticKernel, lsst::afw::math::FixedKernel, lsst::afw::math::Chebyshev1Function2< ReturnT >, lsst::afw::math::PolynomialFunction2< ReturnT >, lsst::afw::math::DoubleGaussianFunction2< ReturnT >, lsst::afw::math::GaussianFunction2< ReturnT >, lsst::afw::math::ChebyshevBoundedField, lsst::afw::image::VisitInfo, lsst::afw::image::PhotoCalib, lsst::afw::image::FilterLabel, lsst::afw::image::CoaddInputs, lsst::afw::image::ApCorrMap, lsst::afw::geom::Transform< FromEndpoint, ToEndpoint >, lsst::afw::geom::Transform< afw::geom::Point2Endpoint, afw::geom::GenericEndpoint >, lsst::afw::geom::SpanSet, lsst::afw::geom::SkyWcs, lsst::afw::geom::polygon::Polygon, lsst::afw::detection::GaussianPsf, lsst::afw::detection::Footprint, lsst::afw::cameraGeom::TransformMap, lsst::afw::cameraGeom::DetectorCollection, lsst::afw::cameraGeom::Detector, and lsst::afw::cameraGeom::Camera.

Definition at line 102 of file Persistable.h.

{ return false; }

operator=() [1/2]

template<typename ReturnT >

Function& lsst::afw::math::Function< ReturnT >::operator= ( Function< ReturnT > &&  )

default

operator=() [2/2]

template<typename ReturnT >

Function& lsst::afw::math::Function< ReturnT >::operator= ( Function< ReturnT > const &  )

default

readFits() [1/3]

static std::shared_ptr<Function< ReturnT > > lsst::afw::table::io::PersistableFacade< Function< ReturnT > >::readFits ( fits::Fits &  fitsfile )

inlinestaticinherited

Read an object from an already open FITS object.

Parameters

[in]

fitsfile

FITS object to read from, already positioned at the desired HDU.

Definition at line 183 of file Persistable.h.

                                                         {
        return dynamicCast(Persistable::_readFits(fitsfile));
    }

readFits() [2/3]

static std::shared_ptr<Function< ReturnT > > lsst::afw::table::io::PersistableFacade< Function< ReturnT > >::readFits ( fits::MemFileManager &  manager, int  hdu = fits::DEFAULT_HDU  )

inlinestaticinherited

Read an object from a FITS file in memory.

Parameters

[in]	manager	Manager for the memory to read from.
[in]	hdu	HDU to read, where 0 is the primary. The special value of afw::fits::DEFAULT_HDU skips the primary HDU if it is empty.

Definition at line 205 of file Persistable.h.

                                                                                             {
        return dynamicCast(Persistable::_readFits(manager, hdu));
    }

readFits() [3/3]

static std::shared_ptr<Function< ReturnT > > lsst::afw::table::io::PersistableFacade< Function< ReturnT > >::readFits ( std::string const &  fileName, int  hdu = fits::DEFAULT_HDU  )

inlinestaticinherited

Read an object from a regular FITS file.

Parameters

[in]	fileName	Name of the file to read.
[in]	hdu	HDU to read, where 0 is the primary. The special value of afw::fits::DEFAULT_HDU skips the primary HDU if it is empty.

Definition at line 194 of file Persistable.h.

                                                                                           {
        return dynamicCast(Persistable::_readFits(fileName, hdu));
    }

setParameter()

template<typename ReturnT >

void lsst::afw::math::Function< ReturnT >::setParameter ( unsigned int  ind, double  newValue  )

inline

Set one function parameter without range checking.

Parameters

ind	index of parameter
newValue	new value for parameter

Definition at line 143 of file Function.h.

    {
        _isCacheValid = false;
        _params[ind] = newValue;
    }

setParameters()

template<typename ReturnT >

void lsst::afw::math::Function< ReturnT >::setParameters ( std::vector< double > const &  params )

inline

Set all function parameters.

Exceptions

lsst::pex::exceptions::InvalidParameterError

if the wrong number of parameters is supplied.

Parameters

params

vector of function parameters

Definition at line 156 of file Function.h.

    {
        if (_params.size() != params.size()) {
            throw LSST_EXCEPT(
                    pexExcept::InvalidParameterError,
                    (boost::format("params has %d entries instead of %d") % params.size() % _params.size())
                            .str());
        }
        _isCacheValid = false;
        _params = params;
    }

toString()

template<typename ReturnT >

virtual std::string lsst::afw::math::Function< ReturnT >::toString ( std::string const &  ) const

inlinevirtual

Return a string representation of the function.

Returns

a string representation of the function

Reimplemented in lsst::afw::math::IntegerDeltaFunction1< ReturnT >, lsst::afw::math::Function2< ReturnT >, lsst::afw::math::Function1< ReturnT >, lsst::afw::math::Function1< Kernel::Pixel >, lsst::afw::math::LanczosFunction2< ReturnT >, lsst::afw::math::LanczosFunction1< ReturnT >, lsst::afw::math::Chebyshev1Function2< ReturnT >, lsst::afw::math::Chebyshev1Function1< ReturnT >, lsst::afw::math::PolynomialFunction2< ReturnT >, lsst::afw::math::PolynomialFunction1< ReturnT >, lsst::afw::math::DoubleGaussianFunction2< ReturnT >, lsst::afw::math::GaussianFunction2< ReturnT >, lsst::afw::math::GaussianFunction1< ReturnT >, lsst::afw::math::IntegerDeltaFunction2< ReturnT >, lsst::afw::math::NearestWarpingKernel::NearestFunction1, and lsst::afw::math::BilinearWarpingKernel::BilinearFunction1.

Definition at line 173 of file Function.h.

                                                       {
        std::stringstream os;
        os << "parameters: [ ";
        for (std::vector<double>::const_iterator i = _params.begin(); i != _params.end(); ++i) {
            if (i != _params.begin()) os << ", ";
            os << *i;
        }
        os << " ]";
        return os.str();
    }

write()

void lsst::afw::table::io::Persistable::write ( OutputArchiveHandle &  handle ) const

protectedvirtualinherited

Write the object to one or more catalogs.

The handle object passed to this function provides an interface for adding new catalogs and adding nested objects to the same archive (while checking for duplicates). See OutputArchiveHandle for more information.

Reimplemented in lsst::afw::typehandling::StorableHelper< Base >, lsst::afw::image::FilterLabel, lsst::meas::modelfit::Mixture, lsst::meas::algorithms::WarpedPsf, lsst::meas::algorithms::SingleGaussianPsf, lsst::meas::algorithms::KernelPsf, lsst::meas::algorithms::DoubleGaussianPsf, lsst::meas::algorithms::CoaddPsf, lsst::meas::algorithms::CoaddBoundedField, lsst::afw::math::WarpingControl, lsst::afw::math::NearestWarpingKernel, lsst::afw::math::BilinearWarpingKernel, lsst::afw::math::LanczosWarpingKernel, lsst::afw::math::TransformBoundedField, lsst::afw::math::ProductBoundedField, lsst::afw::math::PixelAreaBoundedField, lsst::afw::math::LinearCombinationKernel, lsst::afw::math::DeltaFunctionKernel, lsst::afw::math::AnalyticKernel, lsst::afw::math::FixedKernel, lsst::afw::math::ChebyshevBoundedField, lsst::afw::image::VisitInfo, lsst::afw::image::PhotoCalib, lsst::afw::image::CoaddInputs, lsst::afw::geom::Transform< FromEndpoint, ToEndpoint >, lsst::afw::geom::Transform< afw::geom::Point2Endpoint, afw::geom::GenericEndpoint >, lsst::afw::geom::SkyWcs, lsst::afw::geom::polygon::Polygon, lsst::afw::detection::HeavyFootprint< ImagePixelT, MaskPixelT, VariancePixelT >, lsst::afw::detection::GaussianPsf, lsst::afw::detection::Footprint, lsst::afw::cameraGeom::DetectorCollection, lsst::afw::cameraGeom::Camera, lsst::meas::extensions::psfex::PsfexPsf, lsst::afw::math::Chebyshev1Function2< ReturnT >, lsst::afw::math::PolynomialFunction2< ReturnT >, lsst::afw::math::DoubleGaussianFunction2< ReturnT >, and lsst::afw::math::GaussianFunction2< ReturnT >.

Definition at line 38 of file Persistable.cc.

                                                   {
    assert(!isPersistable());
    throw LSST_EXCEPT(pex::exceptions::LogicError,
                      "afw::table-based persistence is not supported for this object.");
}

writeFits() [1/3]

void lsst::afw::table::io::Persistable::writeFits ( fits::Fits &  fitsfile ) const

inherited

Write the object to an already-open FITS object.

Parameters

[in]

fitsfile

Open FITS object to write to.

Definition at line 18 of file Persistable.cc.

                                                    {
    OutputArchive archive;
    archive.put(this);
    archive.writeFits(fitsfile);
}

writeFits() [2/3]

void lsst::afw::table::io::Persistable::writeFits ( fits::MemFileManager &  manager, std::string const &  mode = "w"  ) const

inherited

Write the object to a FITS image in memory.

Parameters

[in]	manager	Name of the file to write to.
[in]	mode	If "w", any existing file with the given name will be overwritten. If "a", new HDUs will be appended to an existing file.

Definition at line 29 of file Persistable.cc.

                                                                                    {
    fits::Fits fitsfile(manager, mode, fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK);
    writeFits(fitsfile);
}

writeFits() [3/3]

void lsst::afw::table::io::Persistable::writeFits ( std::string const &  fileName, std::string const &  mode = "w"  ) const

inherited

Write the object to a regular FITS file.

Parameters

[in]	fileName	Name of the file to write to.
[in]	mode	If "w", any existing file with the given name will be overwritten. If "a", new HDUs will be appended to an existing file.

Definition at line 24 of file Persistable.cc.

                                                                                  {
    fits::Fits fitsfile(fileName, mode, fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK);
    writeFits(fitsfile);
}

Member Data Documentation

_isCacheValid

template<typename ReturnT >

bool lsst::afw::math::Function< ReturnT >::_isCacheValid

mutableprotected

Definition at line 186 of file Function.h.

_params

template<typename ReturnT >

std::vector<double> lsst::afw::math::Function< ReturnT >::_params

protected

Definition at line 185 of file Function.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/afw/22.0.1-42-gca6935d93+ba5e5ca3eb/include/lsst/afw/math/Function.h