lsst::afw::detection::GaussianPsf Class Reference

A circularly symmetric Gaussian Psf class with no spatial variation, intended mostly for testing purposes. More...

#include <GaussianPsf.h>

Inheritance diagram for lsst::afw::detection::GaussianPsf:

Public Types
enum	ImageOwnerEnum { COPY = 0 , INTERNAL = 1 }
	Enum passed to computeImage and computeKernelImage to determine image ownership. More...
using	Pixel = math::Kernel::Pixel
	Pixel type of Image returned by computeImage.
using	Image = image::Image<Pixel>
	Image type returned by computeImage.

Public Member Functions
	GaussianPsf (int width, int height, double sigma)
	Constructor for a GaussianPsf.
	GaussianPsf (lsst::geom::Extent2I const &dimensions, double sigma)
	Constructor for a GaussianPsf.
	~GaussianPsf () override
	GaussianPsf (GaussianPsf const &)
	GaussianPsf (GaussianPsf &&)
GaussianPsf &	operator= (GaussianPsf const &)=delete
GaussianPsf &	operator= (GaussianPsf &&)=delete
std::shared_ptr< afw::detection::Psf >	clone () const override
	Polymorphic deep copy; should usually be unnecessary because Psfs are immutable.
std::shared_ptr< afw::detection::Psf >	resized (int width, int height) const override
	Return a clone with specified kernel dimensions.
lsst::geom::Extent2I	getDimensions () const
	Return the dimensions of the images returned by computeImage()
double	getSigma () const
	Return the radius of the Gaussian.
bool	isPersistable () const noexcept override
	Whether the Psf is persistable; always true.
std::shared_ptr< typehandling::Storable >	cloneStorable () const override
	Polymorphic deep-copy.
std::shared_ptr< Image >	computeImage (lsst::geom::Point2D position, image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
	Return an Image of the PSF, in a form that can be compared directly with star images.
std::shared_ptr< Image >	computeKernelImage (lsst::geom::Point2D position, image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
	Return an Image of the PSF, in a form suitable for convolution.
double	computePeak (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Return the peak value of the PSF image.
double	computeApertureFlux (double radius, lsst::geom::Point2D position, image::Color color=image::Color()) const
	Compute the "flux" of the Psf model within a circular aperture of the given radius.
geom::ellipses::Quadrupole	computeShape (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Compute the ellipse corresponding to the second moments of the Psf.
std::shared_ptr< math::Kernel const >	getLocalKernel (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Return a FixedKernel corresponding to the Psf image at the given point.
image::Color	getAverageColor () const
	Return the average Color of the stars used to construct the Psf.
virtual lsst::geom::Point2D	getAveragePosition () const
	Return the average position of the stars used to construct the Psf.
lsst::geom::Box2I	computeBBox (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Return the bounding box of the image returned by computeKernelImage()
lsst::geom::Box2I	computeImageBBox (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Return the bounding box of the image returned by computeImage()
lsst::geom::Box2I	computeKernelBBox (lsst::geom::Point2D position, image::Color color=image::Color()) const
	Return the bounding box of the image returned by computeImage()
std::size_t	getCacheCapacity () const
	Return the capacity of the caches.
void	setCacheCapacity (std::size_t capacity)
	Set the capacity of the caches.
virtual std::string	toString () const
	Create a string representation of this object (optional operation).
virtual std::size_t	hash_value () const
	Return a hash of this object (optional operation).
virtual bool	equals (Storable const &other) const noexcept
	Compare this object to another Storable.
void	writeFits (std::string const &fileName, std::string const &mode="w") const
	Write the object to a regular FITS file.
void	writeFits (fits::MemFileManager &manager, std::string const &mode="w") const
	Write the object to a FITS image in memory.
void	writeFits (fits::Fits &fitsfile) const
	Write the object to an already-open FITS object.

Static Public Member Functions
static std::shared_ptr< GaussianPsf >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object.
static std::shared_ptr< GaussianPsf >	readFits (std::string const &fileName, int hdu=fits::DEFAULT_HDU)
	Read an object from a regular FITS file.
static std::shared_ptr< GaussianPsf >	readFits (fits::MemFileManager &manager, int hdu=fits::DEFAULT_HDU)
	Read an object from a FITS file in memory.
static std::shared_ptr< GaussianPsf >	dynamicCast (std::shared_ptr< Persistable > const &ptr)
	Dynamically cast a shared_ptr.
static std::shared_ptr< Image >	recenterKernelImage (std::shared_ptr< Image > im, lsst::geom::Point2D const &position, std::string const &warpAlgorithm="lanczos5", unsigned int warpBuffer=5)
	Helper function for Psf::doComputeImage(): converts a kernel image (centered at (0,0) when xy0 is taken into account) to an image centered at position when xy0 is taken into account.
static std::shared_ptr< Psf >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object.
static std::shared_ptr< Psf >	readFits (std::string const &fileName, int hdu=fits::DEFAULT_HDU)
	Read an object from a regular FITS file.
static std::shared_ptr< Psf >	readFits (fits::MemFileManager &manager, int hdu=fits::DEFAULT_HDU)
	Read an object from a FITS file in memory.
static std::shared_ptr< Psf >	dynamicCast (std::shared_ptr< Persistable > const &ptr)
	Dynamically cast a shared_ptr.

Protected Types
using	OutputArchiveHandle = io::OutputArchiveHandle

Protected Member Functions
std::string	getPersistenceName () const override
	Return the unique name used to persist this object and look up its factory.
std::string	getPythonModule () const override
	Return the fully-qualified Python module that should be imported to guarantee that its factory is registered.
void	write (OutputArchiveHandle &handle) const override
	Write the object to one or more catalogs.
virtual std::shared_ptr< Image >	doComputeImage (lsst::geom::Point2D const &position, image::Color const &color) const
	These virtual members are protected (rather than private) so that python-implemented derived classes may opt to use the default implementations.
virtual lsst::geom::Box2I	doComputeImageBBox (lsst::geom::Point2D const &position, image::Color const &color) const

Static Protected Member Functions
template<class T >
static bool	singleClassEquals (T const &lhs, Storable const &rhs)
	Test if a Storable is of a particular class and equal to another object.

Private Member Functions
std::shared_ptr< Image >	doComputeKernelImage (lsst::geom::Point2D const &position, image::Color const &color) const override
	These virtual member functions are private, not protected, because we only want derived classes to implement them, not call them; they should call the corresponding compute*Image member functions instead so as to let the Psf base class handle caching properly.
double	doComputeApertureFlux (double radius, lsst::geom::Point2D const &position, image::Color const &color) const override
geom::ellipses::Quadrupole	doComputeShape (lsst::geom::Point2D const &position, image::Color const &color) const override
lsst::geom::Box2I	doComputeBBox (lsst::geom::Point2D const &position, image::Color const &color) const override

Related Symbols
(Note that these are not member symbols.)
std::ostream &	operator<< (std::ostream &os, Storable const &storable)
	Output operator for Storable.

Detailed Description

A circularly symmetric Gaussian Psf class with no spatial variation, intended mostly for testing purposes.

This class is essentially an alternate implementation of meas::algorithms::SingleGaussianPsf; While SingleGaussianPsf inherits from ImagePsf and KernelPsf, and hence delegates to those various operations relating to the PSF model image (e.g. computeShape()), GaussianPsf computes these analytically.

Definition at line 42 of file GaussianPsf.h.

Member Typedef Documentation

Image

using lsst::afw::detection::Psf::Image = image::Image<Pixel>

inherited

Image type returned by computeImage.

Definition at line 89 of file Psf.h.

OutputArchiveHandle

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

protectedinherited

Definition at line 108 of file Persistable.h.

Pixel

using lsst::afw::detection::Psf::Pixel = math::Kernel::Pixel

inherited

Pixel type of Image returned by computeImage.

Definition at line 88 of file Psf.h.

Member Enumeration Documentation

ImageOwnerEnum

enum lsst::afw::detection::Psf::ImageOwnerEnum

inherited

Enum passed to computeImage and computeKernelImage to determine image ownership.

Enumerator
COPY	The image will be copied before returning; caller will own it.
INTERNAL	An internal image will be returned without copying. The caller must not modify it, and it may be invalidated the next time a Psf member function is called with different color and/or position.

Definition at line 92 of file Psf.h.

                        {
        COPY = 0,    
        INTERNAL = 1 
    };

Constructor & Destructor Documentation

GaussianPsf() [1/4]

lsst::afw::detection::GaussianPsf::GaussianPsf	(	int	width,
		int	height,
		double	sigma )

Constructor for a GaussianPsf.

Parameters

[in]	width	Number of columns in realizations of the PSF at a point.
[in]	height	Number of rows in realizations of the PSF at a point.
[in]	sigma	Radius of the Gaussian.

Definition at line 98 of file GaussianPsf.cc.

        : Psf(true), _dimensions(width, height), _sigma(sigma) {
    checkDimensions(_dimensions);
}

GaussianPsf() [2/4]

lsst::afw::detection::GaussianPsf::GaussianPsf	(	lsst::geom::Extent2I const &	dimensions,
		double	sigma )

Constructor for a GaussianPsf.

Parameters

[in]	dimensions	Number of columns, rows in realizations of the PSF at a point.
[in]	sigma	Radius of the Gaussian.

Definition at line 103 of file GaussianPsf.cc.

        : Psf(true), _dimensions(dimensions), _sigma(sigma) {
    checkDimensions(_dimensions);
}

~GaussianPsf()

lsst::afw::detection::GaussianPsf::~GaussianPsf ( )

overridedefault

GaussianPsf() [3/4]

lsst::afw::detection::GaussianPsf::GaussianPsf ( GaussianPsf const & )

default

GaussianPsf() [4/4]

lsst::afw::detection::GaussianPsf::GaussianPsf ( GaussianPsf && )

default

Member Function Documentation

clone()

std::shared_ptr< afw::detection::Psf > lsst::afw::detection::GaussianPsf::clone ( ) const

overridevirtual

Polymorphic deep copy; should usually be unnecessary because Psfs are immutable.

Implements lsst::afw::detection::Psf.

Definition at line 112 of file GaussianPsf.cc.

                                                        {
    return std::make_shared<GaussianPsf>(_dimensions, _sigma);
}

cloneStorable()

std::shared_ptr< typehandling::Storable > lsst::afw::detection::Psf::cloneStorable ( ) const

inlineoverridevirtualinherited

Polymorphic deep copy; should usually be unnecessary because Psfs are immutable.

This method is an alias of clone that can be called from a reference to Storable.

Reimplemented from lsst::afw::typehandling::Storable.

Definition at line 122 of file Psf.h.

{ return clone(); }

computeApertureFlux()

double Psf::computeApertureFlux ( double radius, lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Compute the "flux" of the Psf model within a circular aperture of the given radius.

Parameters

[in]	radius	Radius of the aperture to measure.
[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

The flux is relative to a Psf image that has been normalized to unit integral, and the radius is in pixels.

Definition at line 165 of file Psf.cc.

                                                                                               {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    return doComputeApertureFlux(radius, position, color);
}

computeBBox()

lsst::geom::Box2I Psf::computeBBox ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Return the bounding box of the image returned by computeKernelImage()

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

Definition at line 127 of file Psf.cc.

                                                                               {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    auto cached_image = _kernelImageCache->get(detail::PsfCacheKey(position, color));
    if (cached_image.has_value()) {
        return cached_image.value()->getBBox();
    } else {
        return doComputeBBox(position, color);
    }
}

computeImage()

std::shared_ptr< Psf::Image > Psf::computeImage ( lsst::geom::Point2D position, image::Color color = image::Color(), ImageOwnerEnum owner = COPY ) const

inherited

Return an Image of the PSF, in a form that can be compared directly with star images.

The specified position is a floating point number, and the resulting image will have a Psf centered on that point when the returned image's xy0 is taken into account.

The returned image is normalized to sum to unity.

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().
[in]	owner	Whether to copy the return value or return an internal image that must be handled with care (see ImageOwnerEnum).

The Psf class caches the most recent return value of computeImage, so repeated calls with the same arguments will be highly optimized.

Note

The real work is done in the virtual private member function Psf::doComputeImage; computeImage only handles caching and default arguments.

Definition at line 101 of file Psf.cc.

                                                                          {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    std::shared_ptr<Psf::Image> result = (*_imageCache)(
            detail::PsfCacheKey(position, color),
            [this](detail::PsfCacheKey const &key) { return doComputeImage(key.position, key.color); });
    if (owner == COPY) {
        result = std::make_shared<Image>(*result, true);
    }
    return result;
}

computeImageBBox()

lsst::geom::Box2I Psf::computeImageBBox ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Return the bounding box of the image returned by computeImage()

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

Definition at line 138 of file Psf.cc.

                                                                                    {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    auto cached_image = _imageCache->get(detail::PsfCacheKey(position, color));
    if (cached_image.has_value()) {
        return cached_image.value()->getBBox();
    } else {
        return doComputeImageBBox(position, color);
    }
}

computeKernelBBox()

lsst::geom::Box2I lsst::afw::detection::Psf::computeKernelBBox ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inlineinherited

Return the bounding box of the image returned by computeImage()

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor(). Alias for computeBBox

Definition at line 282 of file Psf.h.

                                                                               {
        return computeBBox(position, color);
    }

computeKernelImage()

std::shared_ptr< Psf::Image > Psf::computeKernelImage ( lsst::geom::Point2D position, image::Color color = image::Color(), ImageOwnerEnum owner = COPY ) const

inherited

Return an Image of the PSF, in a form suitable for convolution.

While the position need not be an integer, the center of the PSF image returned by computeKernelImage will in the center of the center pixel of the image, which will be (0,0) when the Image's xy0 is taken into account; this is the same behavior as Kernel::computeImage().

The returned image is normalized to sum to unity.

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().
[in]	owner	Whether to copy the return value or return an internal image that must be handled with care (see ImageOwnerEnum).

The Psf class caches the most recent return value of computeKernelImage, so repeated calls with the same arguments will be highly optimized.

Note

The real work is done in the virtual private member function Psf::doComputeKernelImage; computeKernelImage only handles caching and default arguments.

Definition at line 114 of file Psf.cc.

                                                                                {
    if (_isFixed || isPointNull(position)) position = getAveragePosition();
    if (_isFixed || color.isIndeterminate()) color = getAverageColor();
    std::shared_ptr<Psf::Image> result = (*_kernelImageCache)(
            detail::PsfCacheKey(position, color),
            [this](detail::PsfCacheKey const &key) { return doComputeKernelImage(key.position, key.color); });
    if (owner == COPY) {
        result = std::make_shared<Image>(*result, true);
    }
    return result;
}

computePeak()

double Psf::computePeak ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Return the peak value of the PSF image.

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

This calls computeKernelImage internally, but because this will usually be cached, it shouldn't be expensive (but be careful not to accidentally call it with no arguments when you actually want to call it with the same arguments just used to call computeImage or computeKernelImage).

Definition at line 158 of file Psf.cc.

                                                                        {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    std::shared_ptr<Image> image = computeKernelImage(position, color, INTERNAL);
    return (*image)(-image->getX0(), -image->getY0());
}

computeShape()

geom::ellipses::Quadrupole Psf::computeShape ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Compute the ellipse corresponding to the second moments of the Psf.

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

The algorithm used to compute the moments is up to the derived class, and hence this method should not be used when a particular algorithm or weight function is required.

Definition at line 171 of file Psf.cc.

                                                                                         {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    return doComputeShape(position, color);
}

doComputeApertureFlux()

double lsst::afw::detection::GaussianPsf::doComputeApertureFlux ( double radius, lsst::geom::Point2D const & position, image::Color const & color ) const

overrideprivatevirtual

Implements lsst::afw::detection::Psf.

Definition at line 149 of file GaussianPsf.cc.

                                                                         {
    return 1.0 - std::exp(-0.5 * radius * radius / (_sigma * _sigma));
}

doComputeBBox()

lsst::geom::Box2I lsst::afw::detection::GaussianPsf::doComputeBBox ( lsst::geom::Point2D const & position, image::Color const & color ) const

overrideprivatevirtual

Implements lsst::afw::detection::Psf.

Definition at line 159 of file GaussianPsf.cc.

                                                                            {
    return lsst::geom::Box2I(lsst::geom::Point2I(-_dimensions / 2),
                             _dimensions);  // integer truncation intentional
}

doComputeImage()

std::shared_ptr< Psf::Image > Psf::doComputeImage ( lsst::geom::Point2D const & position, image::Color const & color ) const

protectedvirtualinherited

These virtual members are protected (rather than private) so that python-implemented derived classes may opt to use the default implementations.

C++ derived classes may override these methods, but should not call them. Derived classes should call the corresponding compute* member functions instead so as to let the Psf base class handle caching properly.

Derived classes are responsible for ensuring that returned images sum to one.

Reimplemented in lsst::meas::extensions::psfex::PsfexPsf.

Definition at line 177 of file Psf.cc.

                                                                               {
    std::shared_ptr<Psf::Image> im = computeKernelImage(position, color, COPY);
    return recenterKernelImage(im, position);
}

doComputeImageBBox()

lsst::geom::Box2I Psf::doComputeImageBBox ( lsst::geom::Point2D const & position, image::Color const & color ) const

protectedvirtualinherited

Definition at line 183 of file Psf.cc.

                                                                         {
    std::shared_ptr<Psf::Image> im = computeImage(position, color, INTERNAL);
    return im->getBBox();
}

doComputeKernelImage()

std::shared_ptr< GaussianPsf::Image > lsst::afw::detection::GaussianPsf::doComputeKernelImage ( lsst::geom::Point2D const & position, image::Color const & color ) const

overrideprivatevirtual

These virtual member functions are private, not protected, because we only want derived classes to implement them, not call them; they should call the corresponding compute*Image member functions instead so as to let the Psf base class handle caching properly.

Derived classes are responsible for ensuring that returned images sum to one.

Implements lsst::afw::detection::Psf.

Definition at line 134 of file GaussianPsf.cc.

                                                                                               {
    std::shared_ptr<Image> r(new Image(computeBBox(getAveragePosition())));
    Image::Array array = r->getArray();
    double sum = 0.0;
    for (int yIndex = 0, y = r->getY0(); yIndex < _dimensions.getY(); ++yIndex, ++y) {
        Image::Array::Reference row = array[yIndex];
        for (int xIndex = 0, x = r->getX0(); xIndex < _dimensions.getX(); ++xIndex, ++x) {
            sum += row[xIndex] = std::exp(-0.5 * (x * x + y * y) / (_sigma * _sigma));
        }
    }
    ndarray::asEigenMatrix(array) /= sum;
    return r;
}

doComputeShape()

geom::ellipses::Quadrupole lsst::afw::detection::GaussianPsf::doComputeShape ( lsst::geom::Point2D const & position, image::Color const & color ) const

overrideprivatevirtual

Implements lsst::afw::detection::Psf.

Definition at line 154 of file GaussianPsf.cc.

                                                                                      {
    return geom::ellipses::Quadrupole(_sigma * _sigma, _sigma * _sigma, 0.0);
}

dynamicCast() [1/2]

template std::shared_ptr< meas::extensions::psfex::PsfexPsf > lsst::afw::table::io::PersistableFacade< Psf >::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.

dynamicCast() [2/2]

template std::shared_ptr< meas::extensions::psfex::PsfexPsf > lsst::afw::table::io::PersistableFacade< GaussianPsf >::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.

equals()

bool lsst::afw::typehandling::Storable::equals ( Storable const & other ) const

virtualnoexceptinherited

Compare this object to another Storable.

Subclasses that implement equality comparison must override this method to give results consistent with operator== for all inputs that are accepted by both.

Returns

This implementation returns whether the two objects are the same.

Warning

This method compares an object to any type of Storable, although cross-class comparisons should usually return false. If cross-class comparisons are valid, implementers should take care that they are symmetric and will give the same result no matter what the compile-time types of the left- and right-hand sides are.

See also

singleClassEquals

Note

When called on Python classes, this method delegates to __eq__ if it exists.

Reimplemented in lsst::afw::typehandling::StorableHelper< Base >, lsst::afw::geom::polygon::Polygon, lsst::afw::geom::SkyWcs, lsst::afw::image::PhotoCalib, and lsst::afw::image::VisitInfo.

Definition at line 48 of file Storable.cc.

{ return this == &other; }

getAverageColor()

image::Color lsst::afw::detection::Psf::getAverageColor ( ) const

inlineinherited

Return the average Color of the stars used to construct the Psf.

This is also the Color used to return an image if you don't specify a Color.

Definition at line 245 of file Psf.h.

{ return image::Color(); }

getAveragePosition()

lsst::geom::Point2D Psf::getAveragePosition ( ) const

virtualinherited

Return the average position of the stars used to construct the Psf.

This is also the position used to return an image if you don't specify a position.

Reimplemented in lsst::meas::algorithms::CoaddPsf, lsst::meas::algorithms::KernelPsf, lsst::meas::algorithms::WarpedPsf, and lsst::meas::extensions::psfex::PsfexPsf.

Definition at line 189 of file Psf.cc.

{ return lsst::geom::Point2D(); }

getCacheCapacity()

std::size_t Psf::getCacheCapacity ( ) const

inherited

Return the capacity of the caches.

Both the image and kernel image caches have the same capacity.

Definition at line 191 of file Psf.cc.

{ return _kernelImageCache->capacity(); }

getDimensions()

lsst::geom::Extent2I lsst::afw::detection::GaussianPsf::getDimensions ( ) const

inline

Return the dimensions of the images returned by computeImage()

Definition at line 74 of file GaussianPsf.h.

{ return _dimensions; }

getLocalKernel()

std::shared_ptr< math::Kernel const > Psf::getLocalKernel ( lsst::geom::Point2D position, image::Color color = image::Color() ) const

inherited

Return a FixedKernel corresponding to the Psf image at the given point.

Parameters

[in]	position	Position at which to evaluate the PSF.
[in]	color	Color of the source for which to evaluate the PSF; defaults to getAverageColor().

This is implemented by calling computeKernelImage, and is simply provided for convenience.

Definition at line 149 of file Psf.cc.

                                                                                {
    if (isPointNull(position)) position = getAveragePosition();
    if (color.isIndeterminate()) color = getAverageColor();
    // FixedKernel ctor will deep copy image, so we can use INTERNAL.
    std::shared_ptr<Image> image = computeKernelImage(position, color, INTERNAL);
    return std::make_shared<math::FixedKernel>(*image);
}

getPersistenceName()

std::string lsst::afw::detection::GaussianPsf::getPersistenceName ( ) const

overrideprotectedvirtual

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

Must be less than ArchiveIndexSchema::MAX_NAME_LENGTH characters.

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

Definition at line 120 of file GaussianPsf.cc.

{ return "GaussianPsf"; }

getPythonModule()

std::string lsst::afw::detection::GaussianPsf::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 122 of file GaussianPsf.cc.

{ return "lsst.afw.detection"; }

getSigma()

double lsst::afw::detection::GaussianPsf::getSigma ( ) const

inline

Return the radius of the Gaussian.

Definition at line 77 of file GaussianPsf.h.

{ return _sigma; }

hash_value()

std::size_t lsst::afw::typehandling::Storable::hash_value ( ) const

virtualinherited

Return a hash of this object (optional operation).

Exceptions

UnsupportedOperationException

Thrown if this object is not hashable.

Note

C++ subclass authors are responsible for any associated specializations of std::hash.

When called on Python classes, this method delegates to __hash__ if it exists.

Reimplemented in lsst::afw::geom::polygon::Polygon, lsst::afw::image::FilterLabel, lsst::afw::image::VisitInfo, and lsst::afw::typehandling::StorableHelper< Base >.

Definition at line 44 of file Storable.cc.

                                     {
    throw LSST_EXCEPT(UnsupportedOperationException, "Hashes are not supported.");
}

isPersistable()

bool lsst::afw::detection::GaussianPsf::isPersistable ( ) const

inlineoverridevirtualnoexcept

Whether the Psf is persistable; always true.

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

Definition at line 80 of file GaussianPsf.h.

{ return true; }

operator=() [1/2]

GaussianPsf & lsst::afw::detection::GaussianPsf::operator= ( GaussianPsf && )

delete

operator=() [2/2]

GaussianPsf & lsst::afw::detection::GaussianPsf::operator= ( GaussianPsf const & )

delete

readFits() [1/6]

static std::shared_ptr< GaussianPsf > lsst::afw::table::io::PersistableFacade< GaussianPsf >::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.

readFits() [2/6]

static std::shared_ptr< Psf > lsst::afw::table::io::PersistableFacade< Psf >::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.

readFits() [3/6]

static std::shared_ptr< GaussianPsf > lsst::afw::table::io::PersistableFacade< GaussianPsf >::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.

readFits() [4/6]

static std::shared_ptr< Psf > lsst::afw::table::io::PersistableFacade< Psf >::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.

readFits() [5/6]

static std::shared_ptr< GaussianPsf > lsst::afw::table::io::PersistableFacade< GaussianPsf >::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.

readFits() [6/6]

static std::shared_ptr< Psf > lsst::afw::table::io::PersistableFacade< Psf >::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.

recenterKernelImage()

std::shared_ptr< image::Image< double > > Psf::recenterKernelImage ( std::shared_ptr< Image > im, lsst::geom::Point2D const & position, std::string const & warpAlgorithm = "lanczos5", unsigned int warpBuffer = 5 )

staticinherited

Helper function for Psf::doComputeImage(): converts a kernel image (centered at (0,0) when xy0 is taken into account) to an image centered at position when xy0 is taken into account.

warpAlgorithm is passed to afw::math::makeWarpingKernel() and can be "nearest", "bilinear", or "lanczosN"

warpBuffer zero-pads the image before recentering. Recommended value is 1 for bilinear, N for lanczosN (note that it would be cleaner to infer this value from the warping algorithm but this would require mild API changes; same issue occurs in e.g. afw::math::offsetImage()).

The point with integer coordinates (0,0) in the source image (with xy0 taken into account) corresponds to the point position in the destination image. If position is not integer-valued then we will need to fractionally shift the image using interpolation.

Note: if fractional recentering is performed, then a new image will be allocated and returned. If not, then the original image will be returned (after setting XY0).

Definition at line 85 of file Psf.cc.

                                                                                        {
    // "ir" : (integer, residual)
    std::pair<int, double> const irX = image::positionToIndex(position.getX(), true);
    std::pair<int, double> const irY = image::positionToIndex(position.getY(), true);
 
    if (irX.second != 0.0 || irY.second != 0.0) {
        im = math::offsetImage(*im, irX.second, irY.second, warpAlgorithm, warpBuffer);
    }
 
    im->setXY0(irX.first + im->getX0(), irY.first + im->getY0());
    return im;
}

resized()

std::shared_ptr< afw::detection::Psf > lsst::afw::detection::GaussianPsf::resized ( int width, int height ) const

overridevirtual

Return a clone with specified kernel dimensions.

Implements lsst::afw::detection::Psf.

Definition at line 116 of file GaussianPsf.cc.

                                                                               {
    return std::make_shared<GaussianPsf>(lsst::geom::Extent2I(width, height), _sigma);
}

setCacheCapacity()

void Psf::setCacheCapacity ( std::size_t capacity )

inherited

Set the capacity of the caches.

Both the image and kernel image caches will be set to this capacity.

Definition at line 193 of file Psf.cc.

                                             {
    _imageCache->reserve(capacity);
    _kernelImageCache->reserve(capacity);
}

singleClassEquals()

template<class T >

static bool lsst::afw::typehandling::Storable::singleClassEquals ( T const & lhs, Storable const & rhs )

inlinestaticprotectedinherited

Test if a Storable is of a particular class and equal to another object.

This method template simplifies implementations of equals that delegate to operator== without supporting cross-class comparisons.

Template Parameters

T	The class expected of the two objects to be compared.

Parameters

lhs,rhs

The objects to compare. Note that rhs need not be a T, while lhs must be.

Returns

true if rhs is a T and lhs == rhs; false otherwise.

Exception Safety

Provides the same level of exception safety as operator==. Most implementations of operator== do not throw.

Note

This method template calls operator== with both arguments of compile-time type T const&. Its use is not recommended if there would be any ambiguity as to which operator== gets picked by overload resolution.

This method template is typically called from equals as:

bool MyType::equals(Storable const& other) const noexcept {
    return singleClassEquals(*this, other);
}

Definition at line 151 of file Storable.h.

                                                                     {
        auto typedRhs = dynamic_cast<T const*>(&rhs);
        if (typedRhs != nullptr) {
            return lhs == *typedRhs;
        } else {
            return false;
        }
    }

toString()

std::string lsst::afw::typehandling::Storable::toString ( ) const

virtualinherited

Create a string representation of this object (optional operation).

Exceptions

UnsupportedOperationException

Thrown if this object does not have a string representation.

Note

When called on Python classes, this method delegates to __repr__.

Reimplemented in lsst::afw::geom::polygon::Polygon, lsst::afw::geom::SkyWcs, lsst::afw::image::FilterLabel, lsst::afw::image::PhotoCalib, lsst::afw::image::VisitInfo, and lsst::afw::typehandling::StorableHelper< Base >.

Definition at line 40 of file Storable.cc.

                                   {
    throw LSST_EXCEPT(UnsupportedOperationException, "No string representation available.");
}

write()

void lsst::afw::detection::GaussianPsf::write ( OutputArchiveHandle & handle ) const

overrideprotectedvirtual

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

Definition at line 124 of file GaussianPsf.cc.

                                                         {
    static GaussianPsfPersistenceHelper const& keys = GaussianPsfPersistenceHelper::get();
    afw::table::BaseCatalog catalog = handle.makeCatalog(keys.schema);
    std::shared_ptr<afw::table::BaseRecord> record = catalog.addNew();
    (*record)[keys.dimensions.getX()] = _dimensions.getX();
    (*record)[keys.dimensions.getY()] = _dimensions.getY();
    (*record)[keys.sigma] = getSigma();
    handle.saveCatalog(catalog);
}

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);
}

Friends And Related Symbol Documentation

operator<<()

std::ostream & operator<< ( std::ostream & os, Storable const & storable )

related

Output operator for Storable.

Parameters

os	the desired output stream
storable	the object to print

Returns

a reference to os

Exceptions

UnsupportedOperationException

Thrown if storable does not have an implementation of Storable::toString.

Definition at line 174 of file Storable.h.

                                                                        {
    return os << storable.toString();
}

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/afw/g9726552aa6+10f999ec6a/include/lsst/afw/detection/GaussianPsf.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/afw/g9726552aa6+10f999ec6a/src/detection/GaussianPsf.cc