LSSTApplications  19.0.0-11-g2ce9f25+4,20.0.0+1,20.0.0+10,20.0.0+11,20.0.0+13,20.0.0+2,20.0.0+3,20.0.0+4,20.0.0+6,20.0.0-1-g10df615+10,20.0.0-1-g253301a+5,20.0.0-1-g596936a+11,20.0.0-1-g8a53f90+1,20.0.0-1-gc96f8cb+12,20.0.0-1-gd1c87d7+1,20.0.0-17-g41c5faf,20.0.0-2-g04cfba9+4,20.0.0-2-gd11eeda,20.0.0-2-gec03fae+3,20.0.0-3-g082faa5+1,20.0.0-3-gbdbfa727+3,20.0.0-3-gc53c7b6,20.0.0-4-gde602ef96+4,20.0.0-4-ge48a6ca+6,20.0.0-4-ge987224+1,20.0.0-8-g7eef53f7+7,20.0.0-9-g8e1b333,w.2020.28
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lsst::afw::math::Kernel Class Referenceabstract

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

#include <Kernel.h>

Inheritance diagram for lsst::afw::math::Kernel:
lsst::afw::table::io::PersistableFacade< Kernel > lsst::afw::table::io::Persistable lsst::afw::math::AnalyticKernel lsst::afw::math::DeltaFunctionKernel lsst::afw::math::FixedKernel lsst::afw::math::LinearCombinationKernel lsst::afw::math::SeparableKernel lsst::afw::math::BilinearWarpingKernel lsst::afw::math::LanczosWarpingKernel lsst::afw::math::NearestWarpingKernel

Classes

struct  PersistenceHelper
 

Public Types

typedef double Pixel
 
typedef std::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 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...
 
 Kernel (const Kernel &)=delete
 
 Kernel (Kernel &&)=delete
 
Kerneloperator= (const Kernel &)=delete
 
Kerneloperator= (Kernel &&)=delete
 
 ~Kernel () override=default
 
virtual std::shared_ptr< Kernelclone () const =0
 Return a pointer to a deep copy of this kernel. More...
 
virtual std::shared_ptr< Kernelresized (int width, int height) const =0
 Return a pointer to a clone with specified kernel dimensions. 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...
 
lsst::geom::Extent2I const getDimensions () const
 Return the Kernel's dimensions (width, height) More...
 
void setDimensions (lsst::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::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::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< SpatialFunctionPtrgetSpatialFunctionList () const
 Return a list of clones of the spatial functions. More...
 
virtual double getKernelParameter (unsigned int i) const
 Return a particular Kernel Parameter (no bounds checking). More...
 
virtual std::vector< double > getKernelParameters () const
 Return the current kernel parameters. More...
 
lsst::geom::Box2I growBBox (lsst::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. More...
 
lsst::geom::Box2I shrinkBBox (lsst::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. More...
 
void setCtr (lsst::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...
 
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< KernelreadFits (fits::Fits &fitsfile)
 Read an object from an already open FITS object. More...
 
static std::shared_ptr< KernelreadFits (std::string const &fileName, int hdu=fits::DEFAULT_HDU)
 Read an object from a regular FITS file. More...
 
static std::shared_ptr< KernelreadFits (fits::MemFileManager &manager, int hdu=fits::DEFAULT_HDU)
 Read an object from a FITS file in memory. More...
 
static std::shared_ptr< KerneldynamicCast (std::shared_ptr< Persistable > const &ptr)
 Dynamically cast a shared_ptr. More...
 

Protected Types

typedef io::OutputArchiveHandle 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...
 
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...
 
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< SpatialFunctionPtr_spatialFunctionList
 

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 111 of file Kernel.h.

Member Typedef Documentation

◆ kernel_fill_factor

Definition at line 119 of file Kernel.h.

◆ NullSpatialFunction

Definition at line 116 of file Kernel.h.

◆ OutputArchiveHandle

typedef io::OutputArchiveHandle lsst::afw::table::io::Persistable::OutputArchiveHandle
protectedinherited

Definition at line 108 of file Persistable.h.

◆ Pixel

Definition at line 113 of file Kernel.h.

◆ SpatialFunction

Definition at line 115 of file Kernel.h.

◆ SpatialFunctionPtr

Definition at line 114 of file Kernel.h.

Constructor & Destructor Documentation

◆ Kernel() [1/5]

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 58 of file Kernel.cc.

58 : _spatialFunctionList(), _width(0), _height(0), _ctrX(0), _ctrY(0), _nKernelParams(0) {}

◆ Kernel() [2/5]

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.

Parameters
widthnumber of columns
heightnumber of height
nKernelParamsnumber of kernel parameters
spatialFunctionspatial function, or NullSpatialFunction() if none specified
Exceptions
lsst::pex::exceptions::InvalidParameterErrorif a spatial function is specified and the kernel has no parameters.
lsst::pex::exceptions::InvalidParameterErrorif a width or height < 1

Definition at line 60 of file Kernel.cc.

62  _width(width),
63  _height(height),
64  _ctrX((width - 1) / 2),
65  _ctrY((height - 1) / 2),
66  _nKernelParams(nKernelParams) {
67  if ((width < 1) || (height < 1)) {
69  os << "kernel height = " << height << " and/or width = " << width << " < 1";
71  }
72  if (dynamic_cast<const NullSpatialFunction *>(&spatialFunction)) {
73  // spatialFunction is not really present
74  } else {
75  if (nKernelParams == 0) {
76  throw LSST_EXCEPT(pexExcept::InvalidParameterError, "Kernel function has no parameters");
77  }
78  for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
79  SpatialFunctionPtr spatialFunctionCopy = spatialFunction.clone();
80  this->_spatialFunctionList.push_back(spatialFunctionCopy);
81  }
82  }
83 }

◆ Kernel() [3/5]

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.

Parameters
widthnumber of columns
heightnumber of height
spatialFunctionListlist of spatial function, one per kernel parameter
Exceptions
lsst::pex::exceptions::InvalidParameterErrorif a width or height < 1

Definition at line 99 of file Kernel.cc.

100  : _width(width),
101  _height(height),
102  _ctrX(width / 2),
103  _ctrY(height / 2),
104  _nKernelParams(spatialFunctionList.size()) {
105  if ((width < 1) || (height < 1)) {
107  os << "kernel height = " << height << " and/or width = " << width << " < 1";
109  }
110  for (unsigned int ii = 0; ii < spatialFunctionList.size(); ++ii) {
111  SpatialFunctionPtr spatialFunctionCopy = spatialFunctionList[ii]->clone();
112  this->_spatialFunctionList.push_back(spatialFunctionCopy);
113  }
114 }

◆ Kernel() [4/5]

lsst::afw::math::Kernel::Kernel ( const Kernel )
delete

◆ Kernel() [5/5]

lsst::afw::math::Kernel::Kernel ( Kernel &&  )
delete

◆ ~Kernel()

lsst::afw::math::Kernel::~Kernel ( )
overridedefault

Member Function Documentation

◆ clone()

virtual std::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.

◆ computeCache()

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.

Reimplemented in lsst::afw::math::SeparableKernel.

Definition at line 444 of file Kernel.h.

445  {}

◆ computeImage()

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.

Parameters
imageimage whose pixels are to be set (output); xy0 of the image will be set to -kernel.getCtr()
doNormalizenormalize the image (so sum is 1)?
xx (column position) at which to compute spatial function
yy (row position) at which to compute spatial function
Returns
The kernel sum
Exceptions
lsst::pex::exceptions::InvalidParameterErrorif the image is the wrong size
lsst::pex::exceptions::OverflowErrorif doNormalize is true and the kernel sum is exactly 0
Note
computeNewImage has been retired; it doesn't need to be a member

Definition at line 85 of file Kernel.cc.

85  {
86  if (image.getDimensions() != this->getDimensions()) {
88  os << "image dimensions = ( " << image.getWidth() << ", " << image.getHeight() << ") != ("
89  << this->getWidth() << ", " << this->getHeight() << ") = kernel dimensions";
91  }
92  image.setXY0(-_ctrX, -_ctrY);
93  if (this->isSpatiallyVarying()) {
95  }
96  return doComputeImage(image, doNormalize);
97 }

◆ computeKernelParametersFromSpatialModel()

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 144 of file Kernel.cc.

145  {
146  std::vector<double>::iterator paramIter = kernelParams.begin();
148  for (; funcIter != _spatialFunctionList.end(); ++funcIter, ++paramIter) {
149  *paramIter = (*(*funcIter))(x, y);
150  }
151 }

◆ doComputeImage()

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.

Parameters
imageimage whose pixels are to be set (output)
doNormalizenormalize the image (so sum is 1)?
Returns
The kernel sum

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

◆ dynamicCast()

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::LogicErrorif the cast fails

param[in] ptr The pointer to be cast.

Returns
The cast pointer.
Exceptions
lsst::pex::exceptions::TypeErrorIf the dynamic cast fails.

Definition at line 218 of file Persistable.cc.

18  {
19  auto result = std::dynamic_pointer_cast<T>(ptr);
20  if (!result) {
21  throw LSST_EXCEPT(pex::exceptions::TypeError, "Dynamic pointer cast failed");
22  }
23  return result;
24 }

◆ getBBox()

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

return parent bounding box, with XY0 = -center

Definition at line 262 of file Kernel.h.

262  {
263  return lsst::geom::Box2I(lsst::geom::Point2I(-_ctrX, -_ctrY), lsst::geom::Extent2I(_width, _height));
264  }

◆ getCacheSize()

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 450 of file Kernel.h.

450 { return 0; };

◆ getCtr()

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

Return index of kernel's center.

Definition at line 235 of file Kernel.h.

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

◆ getCtrX()

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

Return x index of kernel's center.

Deprecated:
Use getCtr instead

Definition at line 244 of file Kernel.h.

244  {
245  return _ctrX;
246  }

◆ getCtrY()

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

Return y index of kernel's center.

Deprecated:
Use getCtr instead

Definition at line 255 of file Kernel.h.

255  {
256  return _ctrY;
257  }

◆ getDimensions()

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

Return the Kernel's dimensions (width, height)

Definition at line 213 of file Kernel.h.

213 { return lsst::geom::Extent2I(_width, _height); }

◆ getHeight()

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

Return the Kernel's height.

Definition at line 230 of file Kernel.h.

230 { return _height; }

◆ getKernelParameter()

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 300 of file Kernel.h.

300 { return getKernelParameters()[i]; }

◆ getKernelParameters()

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 175 of file Kernel.cc.

175 { return std::vector<double>(); }

◆ getNKernelParameters()

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

Return the number of kernel parameters (0 if none)

Definition at line 269 of file Kernel.h.

269 { return _nKernelParams; }

◆ getNSpatialParameters()

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

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

Definition at line 274 of file Kernel.h.

274  {
275  return this->isSpatiallyVarying() ? _spatialFunctionList[0]->getNParameters() : 0;
276  }

◆ getPersistenceName()

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

◆ getPythonModule()

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

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 235 of file Kernel.cc.

235 { return "lsst.afw.math"; }

◆ getSpatialFunction()

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)

Parameters
indexindex of desired spatial function; must be in range [0, number spatial parameters - 1]
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::InvalidParameterErrorif kernel not spatially varying
lsst::pex::exceptions::InvalidParameterErrorif index out of range

Definition at line 153 of file Kernel.cc.

153  {
154  if (index >= _spatialFunctionList.size()) {
155  if (!this->isSpatiallyVarying()) {
156  throw LSST_EXCEPT(pexExcept::InvalidParameterError, "kernel is not spatially varying");
157  } else {
158  std::ostringstream errStream;
159  errStream << "index = " << index << "; must be < , " << _spatialFunctionList.size();
161  }
162  }
163  return _spatialFunctionList[index]->clone();
164 }

◆ getSpatialFunctionList()

std::vector< 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 166 of file Kernel.cc.

166  {
167  std::vector<SpatialFunctionPtr> spFuncCopyList;
169  spFuncIter != _spatialFunctionList.end(); ++spFuncIter) {
170  spFuncCopyList.push_back((**spFuncIter).clone());
171  }
172  return spFuncCopyList;
173 }

◆ getSpatialParameters()

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 368 of file Kernel.h.

368  {
369  std::vector<std::vector<double>> spatialParams;
371  for (; spFuncIter != _spatialFunctionList.end(); ++spFuncIter) {
372  spatialParams.push_back((*spFuncIter)->getParameters());
373  }
374  return spatialParams;
375  }

◆ getWidth()

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

Return the Kernel's width.

Definition at line 225 of file Kernel.h.

225 { return _width; }

◆ growBBox()

lsst::geom::Box2I lsst::afw::math::Kernel::growBBox ( lsst::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 177 of file Kernel.cc.

177  {
178  return lsst::geom::Box2I(
180  lsst::geom::Extent2I(bbox.getDimensions() + getDimensions() - lsst::geom::Extent2I(1, 1)));
181 }

◆ isPersistable()

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

◆ isSpatiallyVarying()

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

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

Definition at line 380 of file Kernel.h.

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

◆ operator=() [1/2]

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

◆ operator=() [2/2]

Kernel& lsst::afw::math::Kernel::operator= ( Kernel &&  )
delete

◆ readFits() [1/3]

static std::shared_ptr<Kernel > lsst::afw::table::io::PersistableFacade< Kernel >::readFits ( fits::Fits fitsfile)
inlinestaticinherited

Read an object from an already open FITS object.

Parameters
[in]fitsfileFITS object to read from, already positioned at the desired HDU.

Definition at line 183 of file Persistable.h.

183  {
184  return dynamicCast(Persistable::_readFits(fitsfile));
185  }

◆ readFits() [2/3]

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

Read an object from a FITS file in memory.

Parameters
[in]managerManager for the memory to read from.
[in]hduHDU 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.

205  {
206  return dynamicCast(Persistable::_readFits(manager, hdu));
207  }

◆ readFits() [3/3]

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

Read an object from a regular FITS file.

Parameters
[in]fileNameName of the file to read.
[in]hduHDU 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.

194  {
195  return dynamicCast(Persistable::_readFits(fileName, hdu));
196  }

◆ resized()

virtual std::shared_ptr<Kernel> lsst::afw::math::Kernel::resized ( int  width,
int  height 
) const
pure virtual

Return a pointer to a clone with specified kernel dimensions.

Parameters
widthNumber of columns in pixels
heightNumber of rows in pixels
Returns
a pointer to a clone with new dimensions.

Must be implemented by derived classes.

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

◆ setCtr()

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

Set index of kernel's center.

Definition at line 335 of file Kernel.h.

335  {
336  _ctrX = ctr.getX();
337  _ctrY = ctr.getY();
338  _setKernelXY();
339  }

◆ setCtrX()

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

Set x index of kernel's center.

Deprecated:
Use setCtr instead

Definition at line 348 of file Kernel.h.

348  {
349  _ctrX = ctrX;
350  _setKernelXY();
351  }

◆ setCtrY()

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

Set y index of kernel's center.

Deprecated:
Use setCtr instead

Definition at line 360 of file Kernel.h.

360  {
361  _ctrY = ctrY;
362  _setKernelXY();
363  }

◆ setDimensions()

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

Definition at line 215 of file Kernel.h.

215  {
216  _width = dims.getX();
217  _height = dims.getY();
218  }

◆ setHeight()

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

Definition at line 220 of file Kernel.h.

220 { _height = height; }

◆ setKernelParameter()

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::InvalidParameterErroralways (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 224 of file Kernel.cc.

224  {
225  throw LSST_EXCEPT(pexExcept::InvalidParameterError, "Kernel has no kernel parameters");
226 }

◆ setKernelParameters() [1/2]

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 410 of file Kernel.h.

410  {
411  this->setKernelParameter(0, params.first);
412  this->setKernelParameter(1, params.second);
413  }

◆ setKernelParameters() [2/2]

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::RuntimeErrorif the kernel has a spatial function
lsst::pex::exceptions::InvalidParameterErrorif the params vector is the wrong length

Definition at line 388 of file Kernel.h.

388  {
389  if (this->isSpatiallyVarying()) {
390  throw LSST_EXCEPT(lsst::pex::exceptions::RuntimeError, "Kernel is spatially varying");
391  }
392  const unsigned int nParams = this->getNKernelParameters();
393  if (nParams != params.size()) {
395  (boost::format("Number of parameters is wrong, saw %d expected %d") % nParams %
396  params.size())
397  .str());
398  }
399  for (unsigned int ii = 0; ii < nParams; ++ii) {
400  this->setKernelParameter(ii, params[ii]);
401  }
402  }

◆ setKernelParametersFromSpatialModel()

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 228 of file Kernel.cc.

228  {
230  for (int ii = 0; funcIter != _spatialFunctionList.end(); ++funcIter, ++ii) {
231  this->setKernelParameter(ii, (*(*funcIter))(x, y));
232  }
233 }

◆ setSpatialParameters()

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::InvalidParameterErrorif params is the wrong shape (if this exception is thrown then no parameters are changed)

Definition at line 119 of file Kernel.cc.

119  {
120  // Check params size before changing anything
121  unsigned int nKernelParams = this->getNKernelParameters();
122  if (params.size() != nKernelParams) {
123  throw LSST_EXCEPT(
125  (boost::format("params has %d entries instead of %d") % params.size() % nKernelParams).str());
126  }
127  unsigned int nSpatialParams = this->getNSpatialParameters();
128  for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
129  if (params[ii].size() != nSpatialParams) {
131  (boost::format("params[%d] has %d entries instead of %d") % ii %
132  params[ii].size() % nSpatialParams)
133  .str());
134  }
135  }
136  // Set parameters
137  if (nSpatialParams > 0) {
138  for (unsigned int ii = 0; ii < nKernelParams; ++ii) {
139  this->_spatialFunctionList[ii]->setParameters(params[ii]);
140  }
141  }
142 }

◆ setWidth()

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

Definition at line 219 of file Kernel.h.

219 { _width = width; }

◆ shrinkBBox()

lsst::geom::Box2I lsst::afw::math::Kernel::shrinkBBox ( lsst::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::InvalidParameterErrorif the resulting box would have dimension < 1 in either axis

Definition at line 183 of file Kernel.cc.

183  {
184  if ((bbox.getWidth() < getWidth()) || ((bbox.getHeight() < getHeight()))) {
186  os << "bbox dimensions = " << bbox.getDimensions() << " < (" << getWidth() << ", " << getHeight()
187  << ") in one or both dimensions";
189  }
190  return lsst::geom::Box2I(
192  lsst::geom::Extent2I(bbox.getWidth() + 1 - getWidth(), bbox.getHeight() + 1 - getHeight()));
193 }

◆ toString()

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 195 of file Kernel.cc.

195  {
197  os << prefix << "Kernel:" << std::endl;
198  os << prefix << "..height, width: " << _height << ", " << _width << std::endl;
199  os << prefix << "..ctr (X, Y): " << _ctrX << ", " << _ctrY << std::endl;
200  os << prefix << "..nKernelParams: " << _nKernelParams << std::endl;
201  os << prefix << "..isSpatiallyVarying: " << (this->isSpatiallyVarying() ? "True" : "False") << std::endl;
202  if (this->isSpatiallyVarying()) {
203  os << prefix << "..spatialFunctions:" << std::endl;
205  spFuncPtr != _spatialFunctionList.end(); ++spFuncPtr) {
206  os << prefix << "...." << (*spFuncPtr)->toString() << std::endl;
207  }
208  }
209  return os.str();
210 }

◆ 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::math::LinearCombinationKernel, lsst::afw::math::DeltaFunctionKernel, lsst::afw::math::AnalyticKernel, lsst::afw::math::FixedKernel, lsst::afw::image::PhotoCalib, lsst::afw::geom::SkyWcs, lsst::meas::modelfit::Mixture, lsst::afw::detection::Footprint, lsst::afw::geom::Transform< FromEndpoint, ToEndpoint >, lsst::afw::geom::Transform< afw::geom::Point2Endpoint, afw::geom::GenericEndpoint >, lsst::afw::geom::polygon::Polygon, lsst::afw::image::Filter, lsst::afw::math::ChebyshevBoundedField, lsst::afw::image::VisitInfo, lsst::meas::algorithms::CoaddPsf, lsst::afw::cameraGeom::DetectorCollection, lsst::afw::cameraGeom::Camera, lsst::afw::detection::HeavyFootprint< ImagePixelT, MaskPixelT, VariancePixelT >, lsst::meas::algorithms::CoaddBoundedField, lsst::afw::math::PixelAreaBoundedField, lsst::afw::image::CoaddInputs, lsst::afw::detection::GaussianPsf, lsst::afw::math::TransformBoundedField, lsst::afw::math::ProductBoundedField, lsst::meas::algorithms::KernelPsf, lsst::meas::algorithms::DoubleGaussianPsf, lsst::meas::algorithms::SingleGaussianPsf, 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.

38  {
39  assert(!isPersistable());
40  throw LSST_EXCEPT(pex::exceptions::LogicError,
41  "afw::table-based persistence is not supported for this object.");
42 }

◆ 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]fitsfileOpen FITS object to write to.

Definition at line 18 of file Persistable.cc.

18  {
19  OutputArchive archive;
20  archive.put(this);
21  archive.writeFits(fitsfile);
22 }

◆ 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]managerName of the file to write to.
[in]modeIf "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.

29  {
30  fits::Fits fitsfile(manager, mode, fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK);
31  writeFits(fitsfile);
32 }

◆ 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]fileNameName of the file to write to.
[in]modeIf "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.

24  {
25  fits::Fits fitsfile(fileName, mode, fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK);
26  writeFits(fitsfile);
27 }

Member Data Documentation

◆ _spatialFunctionList

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

Definition at line 496 of file Kernel.h.


The documentation for this class was generated from the following files:
y
int y
Definition: SpanSet.cc:49
lsst::afw::image
Backwards-compatibility support for depersisting the old Calib (FluxMag0/FluxMag0Err) objects.
Definition: imageAlgorithm.dox:1
lsst::afw::math::Kernel::setKernelParametersFromSpatialModel
void setKernelParametersFromSpatialModel(double x, double y) const
Set the kernel parameters from the spatial model (if any).
Definition: Kernel.cc:228
lsst::afw::math::Kernel::setKernelParameter
virtual void setKernelParameter(unsigned int ind, double value) const
Set one kernel parameter.
Definition: Kernel.cc:224
lsst::afw::table::io::Persistable::writeFits
void writeFits(std::string const &fileName, std::string const &mode="w") const
Write the object to a regular FITS file.
Definition: Persistable.cc:24
std::string
STL class.
lsst::afw::math::Kernel::getNSpatialParameters
int getNSpatialParameters() const
Return the number of spatial parameters (0 if not spatially varying)
Definition: Kernel.h:274
lsst::afw::math::Kernel::getDimensions
lsst::geom::Extent2I const getDimensions() const
Return the Kernel's dimensions (width, height)
Definition: Kernel.h:213
lsst::afw::math::Kernel::isSpatiallyVarying
bool isSpatiallyVarying() const
Return true iff the kernel is spatially varying (has a spatial function)
Definition: Kernel.h:380
lsst::afw::math::Kernel::getHeight
int getHeight() const
Return the Kernel's height.
Definition: Kernel.h:230
std::vector
STL class.
std::vector::size
T size(T... args)
pex.config.history.format
def format(config, name=None, writeSourceLine=True, prefix="", verbose=False)
Definition: history.py:174
lsst::afw::table::io::Persistable::isPersistable
virtual bool isPersistable() const noexcept
Return true if this particular object can be persisted using afw::table::io.
Definition: Persistable.h:102
lsst::afw::math::Kernel::getCtr
lsst::geom::Point2I getCtr() const
Return index of kernel's center.
Definition: Kernel.h:235
std::vector::push_back
T push_back(T... args)
lsst::afw::math::Kernel::NullSpatialFunction
lsst::afw::math::NullFunction2< double > NullSpatialFunction
Definition: Kernel.h:116
lsst::afw::math::Kernel::doComputeImage
virtual double doComputeImage(lsst::afw::image::Image< Pixel > &image, bool doNormalize) const =0
Low-level version of computeImage.
lsst::afw::fits::Fits::AUTO_CHECK
@ AUTO_CHECK
Definition: fits.h:308
lsst::afw::fits::Fits::AUTO_CLOSE
@ AUTO_CLOSE
Definition: fits.h:307
x
double x
Definition: ChebyshevBoundedField.cc:277
ptr
uint64_t * ptr
Definition: RangeSet.cc:88
result
py::object result
Definition: _schema.cc:429
lsst::afw::math::Kernel::getWidth
int getWidth() const
Return the Kernel's width.
Definition: Kernel.h:225
LSST_EXCEPT
#define LSST_EXCEPT(type,...)
Create an exception with a given type.
Definition: Exception.h:48
std::ostringstream
STL class.
lsst::afw::math::Kernel::_spatialFunctionList
std::vector< SpatialFunctionPtr > _spatialFunctionList
Definition: Kernel.h:496
os
std::ostream * os
Definition: Schema.cc:746
std::endl
T endl(T... args)
lsst::afw::math::Kernel::getKernelParameters
virtual std::vector< double > getKernelParameters() const
Return the current kernel parameters.
Definition: Kernel.cc:175
lsst::pex::exceptions::InvalidParameterError
Reports invalid arguments.
Definition: Runtime.h:66
lsst::afw::table::io::PersistableFacade< Kernel >::dynamicCast
static std::shared_ptr< Kernel > dynamicCast(std::shared_ptr< Persistable > const &ptr)
Dynamically cast a shared_ptr.
Definition: Persistable.cc:18
std::vector::begin
T begin(T... args)
lsst::geom::Extent2I
Extent< int, 2 > Extent2I
Definition: Extent.h:397
lsst::geom::Point< int, 2 >
lsst::geom::Point2I
Point< int, 2 > Point2I
Definition: Point.h:321
lsst::geom::Box2I
An integer coordinate rectangle.
Definition: Box.h:55
std::ostringstream::str
T str(T... args)
lsst::afw::math::Kernel::SpatialFunctionPtr
std::shared_ptr< lsst::afw::math::Function2< double > > SpatialFunctionPtr
Definition: Kernel.h:114
lsst::geom::Extent< int, 2 >
lsst::afw::math::Kernel::getNKernelParameters
unsigned int getNKernelParameters() const
Return the number of kernel parameters (0 if none)
Definition: Kernel.h:269
prefix
std::string prefix
Definition: SchemaMapper.cc:79
bbox
AmpInfoBoxKey bbox
Definition: Amplifier.cc:117
lsst::pex::exceptions::RuntimeError
Reports errors that are due to events beyond the control of the program.
Definition: Runtime.h:104