Kernels are used for convolution with MaskedImages and (eventually) Images. More...

#include <Kernel.h>

Inheritance diagram for lsst.afw.math::Kernel:

Classes
struct	PersistenceHelper

Public Types
typedef double	Pixel

typedef boost::shared_ptr< Kernel >	Ptr

typedef boost::shared_ptr < Kernel const >	ConstPtr

typedef boost::shared_ptr < lsst::afw::math::Function2 < double > >	SpatialFunctionPtr

typedef lsst::afw::math::Function2 < double >	SpatialFunction

typedef lsst::afw::math::NullFunction2 < double >	NullSpatialFunction

typedef generic_kernel_tag	kernel_fill_factor

Public Types inherited from lsst::daf::base::Citizen
enum	{ magicSentinel = 0xdeadbeef }

typedef unsigned long	memId
	Type of the block's ID. More...

typedef memId(*	memNewCallback )(const memId cid)
	A function used to register a callback. More...

typedef memId(*	memCallback )(const Citizen *ptr)

Public Types inherited from lsst::daf::base::Persistable
typedef boost::shared_ptr < Persistable >	Ptr

Public Member Functions
	Kernel ()
	Construct a null Kernel of size 0,0. More...

	Kernel (int width, int height, unsigned int nKernelParams, SpatialFunction const &spatialFunction=NullSpatialFunction())
	Construct a spatially invariant Kernel or a spatially varying Kernel with one spatial function that is duplicated as needed. More...

	Kernel (int width, int height, const std::vector< SpatialFunctionPtr > spatialFunctionList)
	Construct a spatially varying Kernel with a list of spatial functions (one per kernel parameter) More...

virtual	~Kernel ()

virtual boost::shared_ptr< Kernel >	clone () const =0
	Return a pointer to a deep copy of this kernel. More...

double	computeImage (lsst::afw::image::Image< Pixel > &image, bool doNormalize, double x=0.0, double y=0.0) const
	Compute an image (pixellized representation of the kernel) in place. More...

geom::Extent2I const	getDimensions () const
	Return the Kernel's dimensions (width, height) More...

void	setDimensions (geom::Extent2I dims)

void	setWidth (int width)

void	setHeight (int height)

int	getWidth () const
	Return the Kernel's width. More...

int	getHeight () const
	Return the Kernel's height. More...

lsst::afw::geom::Point2I	getCtr () const
	Return index of kernel's center. More...

int	getCtrX () const
	Return x index of kernel's center. More...

int	getCtrY () const
	Return y index of kernel's center. More...

lsst::afw::geom::Box2I	getBBox () const
	return parent bounding box, with XY0 = -center More...

unsigned int	getNKernelParameters () const
	Return the number of kernel parameters (0 if none) More...

int	getNSpatialParameters () const
	Return the number of spatial parameters (0 if not spatially varying) More...

SpatialFunctionPtr	getSpatialFunction (unsigned int index) const
	Return a clone of the specified spatial function (one component of the spatial model) More...

std::vector< SpatialFunctionPtr >	getSpatialFunctionList () const
	Return a list of clones of the spatial functions. More...

virtual double	getKernelParameter (unsigned int i) const

virtual std::vector< double >	getKernelParameters () const
	Return the current kernel parameters. More...

lsst::afw::geom::Box2I	growBBox (lsst::afw::geom::Box2I const &bbox) const

lsst::afw::geom::Box2I	shrinkBBox (lsst::afw::geom::Box2I const &bbox) const

void	setCtr (lsst::afw::geom::Point2I ctr)
	Set index of kernel's center. More...

void	setCtrX (int ctrX)
	Set x index of kernel's center. More...

void	setCtrY (int ctrY)
	Set y index of kernel's center. More...

std::vector< std::vector < double > >	getSpatialParameters () const
	Return the spatial parameters parameters (an empty vector if not spatially varying) More...

bool	isSpatiallyVarying () const
	Return true iff the kernel is spatially varying (has a spatial function) More...

void	setKernelParameters (std::vector< double > const &params)
	Set the kernel parameters of a spatially invariant kernel. More...

void	setKernelParameters (std::pair< double, double > const &params)
	Set the kernel parameters of a 2-component spatially invariant kernel. More...

void	setSpatialParameters (const std::vector< std::vector< double > > params)
	Set the parameters of all spatial functions. More...

void	computeKernelParametersFromSpatialModel (std::vector< double > &kernelParams, double x, double y) const
	Compute the kernel parameters at a specified point. More...

virtual std::string	toString (std::string const &prefix="") const
	Return a string representation of the kernel. More...

virtual void	computeCache (int const )
	Compute a cache of Kernel values, if desired. More...

virtual int	getCacheSize () const
	Get the current size of the kernel cache (0 if none or if caches not supported) More...

Public Member Functions inherited from lsst::daf::base::Citizen
	Citizen (const std::type_info &)

	Citizen (Citizen const &)

	~Citizen ()

Citizen &	operator= (Citizen const &)

std::string	repr () const
	Return a string representation of a Citizen. More...

void	markPersistent (void)
	Mark a Citizen as persistent and not destroyed until process end. More...

memId	getId () const
	Return the Citizen's ID. More...

Public Member Functions inherited from lsst::daf::base::Persistable
	Persistable (void)

virtual	~Persistable (void)

template<class Archive >
void	serialize (Archive &, unsigned int const)

Public Member Functions inherited from lsst.afw.table.io::Persistable
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
	Return true if this particular object can be persisted using afw::table::io. More...

virtual	~Persistable ()

Protected Member Functions
virtual std::string	getPythonModule () const
	Return the fully-qualified Python module that should be imported to guarantee that its factory is registered. More...

virtual void	setKernelParameter (unsigned int ind, double value) const
	Set one kernel parameter. More...

void	setKernelParametersFromSpatialModel (double x, double y) const
	Set the kernel parameters from the spatial model (if any). More...

virtual double	doComputeImage (lsst::afw::image::Image< Pixel > &image, bool doNormalize) const =0
	Low-level version of computeImage. More...

Protected Member Functions inherited from lsst.afw.table.io::Persistable
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...

	Persistable ()

	Persistable (Persistable const &other)

void	operator= (Persistable const &other)

Protected Attributes
std::vector< SpatialFunctionPtr >	_spatialFunctionList

Private Member Functions
	Kernel (const Kernel &)

Kernel &	operator= (const Kernel &)

virtual void	_setKernelXY ()

Private Attributes
int	_width

int	_height

int	_ctrX

int	_ctrY

unsigned int	_nKernelParams

Additional Inherited Members
Static Public Member Functions inherited from lsst::daf::base::Citizen
static bool	hasBeenCorrupted ()
	Check all allocated blocks for corruption. More...

static memId	getNextMemId ()
	Return the memId of the next object to be allocated. More...

static int	init ()
	Called once when the memory system is being initialised. More...

static int	census (int, memId startingMemId=0)
	How many active Citizens are there? More...

static void	census (std::ostream &stream, memId startingMemId=0)
	Print a list of all active Citizens to stream, sorted by ID. More...

static const std::vector < const Citizen * > *	census ()
	Return a (newly allocated) std::vector of active Citizens sorted by ID. More...

static memId	setNewCallbackId (memId id)
	Call the NewCallback when block is allocated. More...

static memId	setDeleteCallbackId (memId id)
	Call the current DeleteCallback when block is deleted. More...

static memNewCallback	setNewCallback (memNewCallback func)
	Set the NewCallback function. More...

static memCallback	setDeleteCallback (memCallback func)
	Set the DeleteCallback function. More...

static memCallback	setCorruptionCallback (memCallback func)
	Set the CorruptionCallback function. More...

Static Public Member Functions inherited from lsst.afw.table.io::PersistableFacade< Kernel >
static boost::shared_ptr< Kernel >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object. More...

static boost::shared_ptr< Kernel >	readFits (std::string const &fileName, int hdu=0)
	Read an object from a regular FITS file. More...

static boost::shared_ptr< Kernel >	readFits (fits::MemFileManager &manager, int hdu=0)
	Read an object from a FITS file in memory. More...

Protected Types inherited from lsst.afw.table.io::Persistable
typedef io::OutputArchiveHandle	OutputArchiveHandle

Detailed Description

Kernels are used for convolution with MaskedImages and (eventually) Images.

Kernel is a virtual base class; it cannot be instantiated. The following notes apply to Kernel and to its subclasses.

The template type should usually be float or double; integer kernels should be used with caution because they do not normalize well.

The center pixel of a Kernel is at index: (width-1)/2, (height-1)/2. Thus it is centered along columns/rows if the kernel has an odd number of columns/rows and shifted 1/2 pixel towards 0 otherwise. A kernel should have an odd number of columns and rows unless it is intended to shift an image.

Spatially Varying Kernels

Kernels may optionally vary spatially (so long as they have any kernel parameters). To make a spatially varying kernel, specify a spatial function at construction (you cannot change your mind once the kernel is constructed). You must also specify a set of spatial parameters, and you may do this at construction and/or later by calling setSpatialParameters. The spatial parameters are a vector (one per kernel function parameter) of spatial function parameters. In other words the spatial parameters are a vector of vectors indexed as [kernel parameter][spatial parameter]. The one spatial function is used to compute the kernel parameters at a given spatial position by computing each kernel parameter using its associated vector of spatial function parameters.

The convolve function computes the spatial function at the pixel position (not index) of the image. See the convolve function for details.

Note that if a kernel is spatially varying then you may not set the kernel parameters directly; that is the job of the spatial function! However, you may change the spatial parameters at any time.

Design Notes

The basic design is to use the same kernel class for both spatially varying and spatially invariant kernels. The user either does or does not supply a function describing the spatial variation at creation time. In addition, analytic kernels are described by a user-supplied function of the same basic type as the spatial variation function.

Several other designs were considered, including: A) Use different classes for spatially varying and spatially invariant versions of each kernel. Thus instead of three basic kernel classes (FixedKernel, AnalyticKernel and LinearCombinationKernel) we would have five (since FixedKernel cannot be spatially varying). Robert Lupton argued that was a needless expansion of the class hiearchy and I agreed. B) Construct analytic kernels by defining a subclass of AnalyticKernel that is specific to the desired functional (e.g. GaussianAnalyticKernel). If spatial models are handled the same way then this creates a serious proliferation of kernel classes (even if we only have two different spatial models, e.g. polynomial and Chebyshev polynomial). I felt it made more sense to define the spatial model by some kind of function class (often called a "functor"), and since we needed such a class, I chose to use it for the analytic kernel as well.

However, having a separate function class does introduce some potential inefficiencies. If a function is part of the class it can potentially be evaluated more quickly than calling a function for each pixel or spatial position.

A possible variant on the current design is to define the spatial model and analytic kernel by specifying the functions as template parameters. This has the potential to regain some efficiency in evaluating the functions. However, it would be difficult or impossible to pre-instantiate the desired template classes, a requirement of the LSST coding standards.

Definition at line 134 of file Kernel.h.

Member Typedef Documentation

typedef boost::shared_ptr< Kernel const> lsst.afw.math::Kernel::ConstPtr

Definition at line 142 of file Kernel.h.

typedef generic_kernel_tag lsst.afw.math::Kernel::kernel_fill_factor

Definition at line 148 of file Kernel.h.

typedef lsst::afw::math::NullFunction2<double> lsst.afw.math::Kernel::NullSpatialFunction

Definition at line 145 of file Kernel.h.

typedef double lsst.afw.math::Kernel::Pixel

Definition at line 140 of file Kernel.h.

typedef boost::shared_ptr< Kernel > lsst.afw.math::Kernel::Ptr

Definition at line 141 of file Kernel.h.

typedef lsst::afw::math::Function2<double> lsst.afw.math::Kernel::SpatialFunction

Definition at line 144 of file Kernel.h.

typedef boost::shared_ptr< lsst::afw::math::Function2<double> > lsst.afw.math::Kernel::SpatialFunctionPtr

Definition at line 143 of file Kernel.h.

Constructor & Destructor Documentation

lsst.afw.math::Kernel::Kernel ( )

explicit

Construct a null Kernel of size 0,0.

A null constructor is primarily intended for persistence.

Definition at line 51 of file Kernel.cc.

 :
     daf::base::Citizen(typeid(this)),
     _spatialFunctionList(),
     _width(0),
     _height(0),
     _ctrX(0),
     _ctrY(0),
     _nKernelParams(0)
 {}

lsst.afw.math::Kernel::Kernel	(	int	width,
		int	height,
		unsigned int	nKernelParams,
		SpatialFunction const &	spatialFunction = `NullSpatialFunction()`
	)

explicit

Construct a spatially invariant Kernel or a spatially varying Kernel with one spatial function that is duplicated as needed.

Exceptions

lsst::pex::exceptions::InvalidParameterError	if a spatial function is specified and the kernel has no parameters.
lsst::pex::exceptions::InvalidParameterError	if a width or height < 1

Parameters

width	number of columns
height	number of height
nKernelParams	number of kernel parameters
spatialFunction	spatial function, or NullSpatialFunction() if none specified

Definition at line 62 of file Kernel.cc.

 :
     daf::base::Citizen(typeid(this)),
     _spatialFunctionList(),
     _width(width),
     _height(height),
     _ctrX((width-1)/2),
     _ctrY((height-1)/2),
     _nKernelParams(nKernelParams)
 {
     if ((width < 1) || (height < 1)) {
         std::ostringstream os;
         os << "kernel height = " << height << " and/or width = " << width << " < 1";
         throw LSST_EXCEPT(pexExcept::InvalidParameterError, os.str());
     }
     if (dynamic_cast<const NullSpatialFunction*>(&spatialFunction)) {
         // spatialFunction is not really present
     } else {
         if (nKernelParams == 0) {
             throw LSST_EXCEPT(pexExcept::InvalidParameterError, "Kernel function has no parameters");
         }
         for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
             SpatialFunctionPtr spatialFunctionCopy = spatialFunction.clone();
             this->_spatialFunctionList.push_back(spatialFunctionCopy);
         }
     }
 }

lsst.afw.math::Kernel::Kernel	(	int	width,
		int	height,
		const std::vector< SpatialFunctionPtr >	spatialFunctionList
	)

explicit

Construct a spatially varying Kernel with a list of spatial functions (one per kernel parameter)

Note: if the list of spatial functions is empty then the kernel is not spatially varying.

Exceptions

lsst::pex::exceptions::InvalidParameterError if a width or height < 1

Parameters

width	number of columns
height	number of height
spatialFunctionList	list of spatial function, one per kernel parameter

Definition at line 113 of file Kernel.cc.

 :
     daf::base::Citizen(typeid(this)),
    _width(width),
    _height(height),
    _ctrX(width/2),
    _ctrY(height/2),
    _nKernelParams(spatialFunctionList.size())
 {
     if ((width < 1) || (height < 1)) {
         std::ostringstream os;
         os << "kernel height = " << height << " and/or width = " << width << " < 1";
         throw LSST_EXCEPT(pexExcept::InvalidParameterError, os.str());
     }
     for (unsigned int ii = 0; ii < spatialFunctionList.size(); ++ii) {
         SpatialFunctionPtr spatialFunctionCopy = spatialFunctionList[ii]->clone();
         this->_spatialFunctionList.push_back(spatialFunctionCopy);
     }
 }

virtual lsst.afw.math::Kernel::~Kernel ( )

inlinevirtual

Definition at line 187 of file Kernel.h.

187 {}

lsst.afw.math::Kernel::Kernel ( const Kernel & )

private

Member Function Documentation

virtual void lsst.afw.math::Kernel::_setKernelXY ( )

inlineprivatevirtual

Reimplemented in lsst.afw.math::SeparableKernel.

Definition at line 539 of file Kernel.h.

539 {}

virtual boost::shared_ptr< Kernel > lsst.afw.math::Kernel::clone ( ) const

pure virtual

Return a pointer to a deep copy of this kernel.

This kernel exists instead of a copy constructor so one can obtain a copy of an actual kernel instead of a useless copy of the base class.

Every kernel subclass must override this method.

Returns: a pointer to a deep copy of the kernel

Implemented in lsst.afw.math::SeparableKernel, lsst.afw.math::LinearCombinationKernel, lsst.afw.math::DeltaFunctionKernel, lsst.afw.math::AnalyticKernel, lsst.afw.math::FixedKernel, lsst.afw.math::NearestWarpingKernel, lsst.afw.math::BilinearWarpingKernel, and lsst.afw.math::LanczosWarpingKernel.

virtual void lsst.afw.math::Kernel::computeCache ( int const )

inlinevirtual

Compute a cache of Kernel values, if desired.

Warning: : few kernel classes actually support this, in which case this is a no-op and getCacheSize always returns 0.

Parameters

const desired cache size

Reimplemented in lsst.afw.math::SeparableKernel.

Definition at line 469 of file Kernel.h.

471 {}

double lsst.afw.math::Kernel::computeImage	(	lsst::afw::image::Image< Pixel > &	image,
		bool	doNormalize,
		double	x = `0.0`,
		double	y = `0.0`
	)		const

Compute an image (pixellized representation of the kernel) in place.

x, y are ignored if there is no spatial function.

Returns: The kernel sum

Note: computeNewImage has been retired; it doesn't need to be a member

Exceptions

lsst::pex::exceptions::InvalidParameterError	if the image is the wrong size
lsst::pex::exceptions::OverflowError	if doNormalize is true and the kernel sum is exactly 0

Parameters

image	image whose pixels are to be set (output); xy0 of the image will be set to -kernel.getCtr()
doNormalize	normalize the image (so sum is 1)?
x	x (column position) at which to compute spatial function
y	y (row position) at which to compute spatial function

Definition at line 94 of file Kernel.cc.

         {
     if (image.getDimensions() != this->getDimensions()) {
         std::ostringstream os;
         os << "image dimensions = ( " << image.getWidth() << ", " << image.getHeight()
             << ") != (" << this->getWidth() << ", " << this->getHeight() << ") = kernel dimensions";
         throw LSST_EXCEPT(pexExcept::InvalidParameterError, os.str());
     }
     image.setXY0(-_ctrX, -_ctrY);
     if (this->isSpatiallyVarying()) {
         this->setKernelParametersFromSpatialModel(x, y);
     }
     return doComputeImage(image, doNormalize);
 }

void lsst.afw.math::Kernel::computeKernelParametersFromSpatialModel	(	std::vector< double > &	kernelParams,
		double	x,
		double	y
	)		const

Compute the kernel parameters at a specified point.

Warning: this is a low-level function that assumes kernelParams is the right length. It will fail in unpredictable ways if that condition is not met.

Definition at line 162 of file Kernel.cc.

                                                                {
     std::vector<double>::iterator paramIter = kernelParams.begin();
     std::vector<SpatialFunctionPtr>::const_iterator funcIter = _spatialFunctionList.begin();
     for ( ; funcIter != _spatialFunctionList.end(); ++funcIter, ++paramIter) {
         *paramIter = (*(*funcIter))(x,y);
     }
 }

virtual double lsst.afw.math::Kernel::doComputeImage	(	lsst::afw::image::Image< Pixel > &	image,
		bool	doNormalize
	)		const

protectedpure virtual

Low-level version of computeImage.

Before this is called the image dimensions are checked, the image's xy0 is set and the kernel's parameters are set. This routine sets the pixels, including normalization if requested.

Returns: The kernel sum

Parameters

image	image whose pixels are to be set (output)
doNormalize	normalize the image (so sum is 1)?

Implemented in lsst.afw.math::SeparableKernel, lsst.afw.math::LinearCombinationKernel, lsst.afw.math::DeltaFunctionKernel, lsst.afw.math::AnalyticKernel, and lsst.afw.math::FixedKernel.

lsst::afw::geom::Box2I lsst.afw.math::Kernel::getBBox ( ) const

inline

return parent bounding box, with XY0 = -center

Definition at line 279 of file Kernel.h.

                                                 {
             return lsst::afw::geom::Box2I(
                 lsst::afw::geom::Point2I(-_ctrX, -_ctrY),
                 lsst::afw::geom::Extent2I(_width, _height)
             );
         }

virtual int lsst.afw.math::Kernel::getCacheSize ( ) const

inlinevirtual

Get the current size of the kernel cache (0 if none or if caches not supported)

Reimplemented in lsst.afw.math::SeparableKernel.

Definition at line 476 of file Kernel.h.

476 { return 0; };

lsst::afw::geom::Point2I lsst.afw.math::Kernel::getCtr ( ) const

inline

Return index of kernel's center.

Definition at line 254 of file Kernel.h.

                                                  {
             return lsst::afw::geom::Point2I(_ctrX, _ctrY);
         }

int lsst.afw.math::Kernel::getCtrX ( ) const

inline

Return x index of kernel's center.

Deprecated:: Use getCtr instead

Definition at line 263 of file Kernel.h.

                                    {
             return _ctrX;
         }

int lsst.afw.math::Kernel::getCtrY ( ) const

inline

Return y index of kernel's center.

Deprecated:: Use getCtr instead

Definition at line 272 of file Kernel.h.

                                    {
             return _ctrY;
         }

geom::Extent2I const lsst.afw.math::Kernel::getDimensions ( ) const

inline

Return the Kernel's dimensions (width, height)

Definition at line 226 of file Kernel.h.

226 {

227 return geom::Extent2I(_width, _height); }

lsst.afw.math::Kernel::_width

int _width

Definition: Kernel.h:529

lsst.afw.math::Kernel::_height

int _height

Definition: Kernel.h:530

lsst.afw.geom::Extent2I

Extent< int, 2 > Extent2I

Definition: Extent.h:355

int lsst.afw.math::Kernel::getHeight ( ) const

inline

Return the Kernel's height.

Definition at line 247 of file Kernel.h.

                                      {
             return _height;
         }

virtual double lsst.afw.math::Kernel::getKernelParameter ( unsigned int i ) const

inlinevirtual

Return a particular Kernel Parameter (no bounds checking). This version is slow, but specialisations may be faster

Reimplemented in lsst.afw.math::SeparableKernel.

Definition at line 324 of file Kernel.h.

                                                                 {
             return getKernelParameters()[i];
         }

std::vector< double > lsst.afw.math::Kernel::getKernelParameters ( ) const

virtual

Return the current kernel parameters.

If the kernel is spatially varying then the parameters are those last computed. See also computeKernelParametersFromSpatialModel. If there are no kernel parameters then returns an empty vector.

Reimplemented in lsst.afw.math::SeparableKernel, lsst.afw.math::LinearCombinationKernel, and lsst.afw.math::AnalyticKernel.

Definition at line 196 of file Kernel.cc.

                                                            {
     return std::vector<double>();
 }

unsigned int lsst.afw.math::Kernel::getNKernelParameters ( ) const

inline

Return the number of kernel parameters (0 if none)

Definition at line 289 of file Kernel.h.

                                                          {
             return _nKernelParams;
         }

int lsst.afw.math::Kernel::getNSpatialParameters ( ) const

inline

Return the number of spatial parameters (0 if not spatially varying)

Definition at line 296 of file Kernel.h.

                                                  {
             return this->isSpatiallyVarying() ? _spatialFunctionList[0]->getNParameters() : 0;
         }

std::string lsst.afw.math::Kernel::getPythonModule ( ) const

protectedvirtual

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 264 of file Kernel.cc.

264 { return "lsst.afw.math"; }

afwMath::Kernel::SpatialFunctionPtr lsst.afw.math::Kernel::getSpatialFunction ( unsigned int index ) const

Return a clone of the specified spatial function (one component of the spatial model)

Returns: a shared pointer to a spatial function. The function is a deep copy, so setting its parameters has no effect on the kernel.

Exceptions

lsst::pex::exceptions::InvalidParameterError	if kernel not spatially varying
lsst::pex::exceptions::InvalidParameterError	if index out of range

Parameters

index index of desired spatial function; must be in range [0, number spatial parameters - 1]

Definition at line 171 of file Kernel.cc.

         {
     if (index >= _spatialFunctionList.size()) {
         if (!this->isSpatiallyVarying()) {
             throw LSST_EXCEPT(pexExcept::InvalidParameterError, "kernel is not spatially varying");
         } else {
             std::ostringstream errStream;
             errStream << "index = " << index << "; must be < , " << _spatialFunctionList.size();
             throw LSST_EXCEPT(pexExcept::InvalidParameterError, errStream.str());
         }
     }
     return _spatialFunctionList[index]->clone();
 }

std::vector< afwMath::Kernel::SpatialFunctionPtr > lsst.afw.math::Kernel::getSpatialFunctionList ( ) const

Return a list of clones of the spatial functions.

Returns: a list of shared pointers to spatial functions. The functions are deep copies, so setting their parameters has no effect on the kernel.

Definition at line 186 of file Kernel.cc.

         {
     std::vector<SpatialFunctionPtr> spFuncCopyList;
     for (std::vector<SpatialFunctionPtr>::const_iterator spFuncIter = _spatialFunctionList.begin();
         spFuncIter != _spatialFunctionList.end(); ++spFuncIter) {
         spFuncCopyList.push_back((**spFuncIter).clone());
     }
     return spFuncCopyList;
 }

std::vector<std::vector<double> > lsst.afw.math::Kernel::getSpatialParameters ( ) const

inline

Return the spatial parameters parameters (an empty vector if not spatially varying)

Definition at line 390 of file Kernel.h.

                                                                           {
             std::vector<std::vector<double> > spatialParams;
             std::vector<SpatialFunctionPtr>::const_iterator spFuncIter = _spatialFunctionList.begin();
             for ( ; spFuncIter != _spatialFunctionList.end(); ++spFuncIter) {
                 spatialParams.push_back((*spFuncIter)->getParameters());
             }
             return spatialParams;
         }

int lsst.afw.math::Kernel::getWidth ( ) const

inline

Return the Kernel's width.

Definition at line 240 of file Kernel.h.

                                     {
             return _width;
         }

afwGeom::Box2I lsst.afw.math::Kernel::growBBox ( lsst::afw::geom::Box2I const & bbox ) const

Given a bounding box for pixels one wishes to compute by convolving an image with this kernel, return the bounding box of pixels that must be accessed on the image to be convolved. Thus the box shifted by -kernel.getCtr() and its size is expanded by kernel.getDimensions()-1.

Returns: the bbox expanded by the kernel.

Definition at line 201 of file Kernel.cc.

                                                                    {
     return afwGeom::Box2I(
         afwGeom::Point2I(bbox.getMin() - afwGeom::Extent2I(getCtr())),
         afwGeom::Extent2I(bbox.getDimensions() + getDimensions() - afwGeom::Extent2I(1,1)));
 }

bool lsst.afw.math::Kernel::isSpatiallyVarying ( ) const

inline

Return true iff the kernel is spatially varying (has a spatial function)

Definition at line 402 of file Kernel.h.

                                                {
             return _spatialFunctionList.size() != 0;
         }

Kernel& lsst.afw.math::Kernel::operator= ( const Kernel & )

private

void lsst.afw.math::Kernel::setCtr ( lsst::afw::geom::Point2I ctr )

inline

Set index of kernel's center.

Definition at line 361 of file Kernel.h.

                                                    {
             _ctrX = ctr.getX();
             _ctrY = ctr.getY();
             _setKernelXY();
         }

void lsst.afw.math::Kernel::setCtrX ( int ctrX )

inline

Set x index of kernel's center.

Deprecated:: Use setCtr instead

Definition at line 372 of file Kernel.h.

                                       {
             _ctrX = ctrX;
             _setKernelXY();
         }

void lsst.afw.math::Kernel::setCtrY ( int ctrY )

inline

Set y index of kernel's center.

Deprecated:: Use setCtr instead

Definition at line 382 of file Kernel.h.

                                       {
             _ctrY = ctrY;
             _setKernelXY();
         }

void lsst.afw.math::Kernel::setDimensions ( geom::Extent2I dims )

inline

Definition at line 229 of file Kernel.h.

                                               {
             _width = dims.getX();
             _height = dims.getY();
             
         }

void lsst.afw.math::Kernel::setHeight ( int height )

inline

Definition at line 235 of file Kernel.h.

235 { _height = height; }

lsst.afw.math::Kernel::_height

int _height

Definition: Kernel.h:530

void lsst.afw.math::Kernel::setKernelParameter	(	unsigned int	ind,
		double	value
	)		const

protectedvirtual

Set one kernel parameter.

Classes that have kernel parameters must subclass this function.

This function is marked "const", despite modifying unimportant internals, so that computeImage can be const.

Exceptions

lsst::pex::exceptions::InvalidParameterError always (unless subclassed)

Reimplemented in lsst.afw.math::SeparableKernel, lsst.afw.math::LinearCombinationKernel, lsst.afw.math::AnalyticKernel, lsst.afw.math::NearestWarpingKernel, lsst.afw.math::BilinearWarpingKernel, and lsst.afw.math::LanczosWarpingKernel.

Definition at line 253 of file Kernel.cc.

                                                                  {
     throw LSST_EXCEPT(pexExcept::InvalidParameterError, "Kernel has no kernel parameters");
 }

void lsst.afw.math::Kernel::setKernelParameters ( std::vector< double > const & params )

inline

Set the kernel parameters of a spatially invariant kernel.

Exceptions

lsst::pex::exceptions::RuntimeError	if the kernel has a spatial function
lsst::pex::exceptions::InvalidParameterError	if the params vector is the wrong length

Definition at line 412 of file Kernel.h.

                                                                          {
             if (this->isSpatiallyVarying()) {
                 throw LSST_EXCEPT(lsst::pex::exceptions::RuntimeError,
                     "Kernel is spatially varying");
             }
             const unsigned int nParams = this->getNKernelParameters();
             if (nParams != params.size()) {
                 throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                                   (boost::format("Number of parameters is wrong, saw %d expected %d") %
                                    nParams % params.size()).str());
             }
             for (unsigned int ii = 0; ii < nParams; ++ii) {
                 this->setKernelParameter(ii, params[ii]);
             }
         }

void lsst.afw.math::Kernel::setKernelParameters ( std::pair< double, double > const & params )

inline

Set the kernel parameters of a 2-component spatially invariant kernel.

Warning: This is a low-level method intended for maximum efficiency when using warping kernels. No error checking is performed. Use the std::vector<double> form if you want safety.

Definition at line 434 of file Kernel.h.

                                                                                {
             this->setKernelParameter(0, params.first);
             this->setKernelParameter(1, params.second);
         }

void lsst.afw.math::Kernel::setKernelParametersFromSpatialModel	(	double	x,
		double	y
	)		const

protected

Set the kernel parameters from the spatial model (if any).

This function has no effect if there is no spatial model.

This function is marked "const", despite modifying unimportant internals, so that computeImage can be const.

Definition at line 257 of file Kernel.cc.

                                                                                 {
     std::vector<SpatialFunctionPtr>::const_iterator funcIter = _spatialFunctionList.begin();
     for (int ii = 0; funcIter != _spatialFunctionList.end(); ++funcIter, ++ii) {
         this->setKernelParameter(ii, (*(*funcIter))(x,y));
     }
 }

void lsst.afw.math::Kernel::setSpatialParameters ( const std::vector< std::vector< double > > params )

Set the parameters of all spatial functions.

Params is indexed as [kernel parameter][spatial parameter]

Exceptions

lsst::pex::exceptions::InvalidParameterError if params is the wrong shape (if this exception is thrown then no parameters are changed)

Definition at line 139 of file Kernel.cc.

                                                                                    {
     // Check params size before changing anything
     unsigned int nKernelParams = this->getNKernelParameters();
     if (params.size() != nKernelParams) {
         throw LSST_EXCEPT(pexExcept::InvalidParameterError,
             (boost::format("params has %d entries instead of %d") % params.size() % nKernelParams).str());
     }
     unsigned int nSpatialParams = this->getNSpatialParameters();
     for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
         if (params[ii].size() != nSpatialParams) {
             throw LSST_EXCEPT(pexExcept::InvalidParameterError,
                 (boost::format("params[%d] has %d entries instead of %d") %
                 ii % params[ii].size() % nSpatialParams).str());
         }
     }
     // Set parameters
     if (nSpatialParams > 0) {
         for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
             this->_spatialFunctionList[ii]->setParameters(params[ii]);
         }
     }
 }

void lsst.afw.math::Kernel::setWidth ( int width )

inline

Definition at line 234 of file Kernel.h.

234 { _width = width; }

lsst.afw.math::Kernel::_width

int _width

Definition: Kernel.h:529

afwGeom::Box2I lsst.afw.math::Kernel::shrinkBBox ( lsst::afw::geom::Box2I const & bbox ) const

Given a bounding box for an image one wishes to convolve with this kernel, return the bounding box for the region of pixels that can be computed. Thus the box shifted by kernel.getCtr() and its size is reduced by kernel.getDimensions()-1.

Returns: the bbox shrunk by the kernel.

Exceptions

lsst::pex::exceptions::InvalidParameterError if the resulting box would have dimension < 1 in either axis

Definition at line 207 of file Kernel.cc.

                                                                      {
     if ((bbox.getWidth() < getWidth()) || ((bbox.getHeight() < getHeight()))) {
         std::ostringstream os;
         os << "bbox dimensions = " << bbox.getDimensions() << " < ("
            << getWidth() << ", " << getHeight() << ") in one or both dimensions";
         throw LSST_EXCEPT(pexExcept::InvalidParameterError, os.str());
     }
     return afwGeom::Box2I(
         afwGeom::Point2I(
             bbox.getMinX() + getCtrX(),
             bbox.getMinY() + getCtrY()),
         afwGeom::Extent2I(
             bbox.getWidth()  + 1 - getWidth(),
             bbox.getHeight() + 1 - getHeight()));
 }

std::string lsst.afw.math::Kernel::toString ( std::string const & prefix = "" ) const

virtual

Return a string representation of the kernel.

Reimplemented in lsst.afw.math::SeparableKernel, lsst.afw.math::LinearCombinationKernel, lsst.afw.math::DeltaFunctionKernel, lsst.afw.math::AnalyticKernel, and lsst.afw.math::FixedKernel.

Definition at line 224 of file Kernel.cc.

                                                                {
     std::ostringstream os;
     os << prefix << "Kernel:" << std::endl;
     os << prefix << "..height, width: " << _height << ", " << _width << std::endl;
     os << prefix << "..ctr (X, Y): " << _ctrX << ", " << _ctrY << std::endl;
     os << prefix << "..nKernelParams: " << _nKernelParams << std::endl;
     os << prefix << "..isSpatiallyVarying: " << (this->isSpatiallyVarying() ? "True" : "False") << std::endl;
     if (this->isSpatiallyVarying()) {
         os << prefix << "..spatialFunctions:" << std::endl;
         for (std::vector<SpatialFunctionPtr>::const_iterator spFuncPtr = _spatialFunctionList.begin();
             spFuncPtr != _spatialFunctionList.end(); ++spFuncPtr) {
             os << prefix << "...." << (*spFuncPtr)->toString() << std::endl;
         }
     }
     return os.str();
 }

Member Data Documentation

int lsst.afw.math::Kernel::_ctrX

private

Definition at line 531 of file Kernel.h.

int lsst.afw.math::Kernel::_ctrY

private

Definition at line 532 of file Kernel.h.

int lsst.afw.math::Kernel::_height

private

Definition at line 530 of file Kernel.h.

unsigned int lsst.afw.math::Kernel::_nKernelParams

private

Definition at line 533 of file Kernel.h.

std::vector<SpatialFunctionPtr> lsst.afw.math::Kernel::_spatialFunctionList

protected

Definition at line 524 of file Kernel.h.

int lsst.afw.math::Kernel::_width

private

Definition at line 529 of file Kernel.h.

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

/home/lsstsw/stack/Linux64/afw/11.0.rc2+4/include/lsst/afw/math/Kernel.h
/home/lsstsw/stack/Linux64/afw/11.0.rc2+4/src/math/Kernel.cc

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