Class DeltaFunctionKernel

Inheritance Relationships

Base Types

Class Documentation

class DeltaFunctionKernel : public lsst::afw::table::io::PersistableFacade<DeltaFunctionKernel>, public lsst::afw::math::Kernel

A kernel that has only one non-zero pixel (of value 1)

It has no adjustable parameters and so cannot be spatially varying.

Public Types

typedef deltafunction_kernel_tag kernel_fill_factor

Public Functions

DeltaFunctionKernel(int width, int height, lsst::geom::Point2I const &point)

Construct a spatially invariant DeltaFunctionKernel

Parameters

  • width: kernel size (columns)

  • height: kernel size (rows)

  • point: index of active pixel (where 0,0 is the lower left corner)

Exceptions

  • pex::exceptions::InvalidParameterError: if active pixel is off the kernel

DeltaFunctionKernel(const DeltaFunctionKernel&)
DeltaFunctionKernel(DeltaFunctionKernel&&)
DeltaFunctionKernel &operator=(const DeltaFunctionKernel&)
DeltaFunctionKernel &operator=(DeltaFunctionKernel&&)
~DeltaFunctionKernel()
std::shared_ptr<Kernel> clone() const

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.

Return

a pointer to a deep copy of the kernel

std::shared_ptr<Kernel> resized(int width, int height) const

Return a pointer to a clone with specified kernel dimensions

Must be implemented by derived classes.

Return

a pointer to a clone with new dimensions.

Parameters

  • width: Number of columns in pixels

  • height: Number of rows in pixels

lsst::geom::Point2I getPixel() const
std::string toString(std::string const &prefix = "") const

Return a string representation of the kernel

bool isPersistable() const

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

Protected Functions

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

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.

Return

The kernel sum

Parameters

  • image: image whose pixels are to be set (output)

  • doNormalize: normalize the image (so sum is 1)?

std::string getPersistenceName() const

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

Must be less than ArchiveIndexSchema::MAX_NAME_LENGTH characters.

void write(OutputArchiveHandle &handle) const

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.