lsst::meas::base::SincCoeffs< PixelT > Class Template Reference

A singleton to calculate and cache the coefficients for sinc photometry. More...

#include <SincCoeffs.h>

Public Types
typedef afw::image::Image< PixelT >	CoeffT

Static Public Member Functions
static void	cache (float rInner, float rOuter)
	Cache the coefficients for a particular aperture.
static std::shared_ptr< CoeffT const >	get (afw::geom::ellipses::Axes const &outerEllipse, float const innerRadiusFactor=0.0)
	Get the coefficients for an aperture.
static std::shared_ptr< CoeffT >	calculate (afw::geom::ellipses::Axes const &outerEllipse, double const innerFactor=0.0)
	Calculate the coefficients for an aperture.

Detailed Description

template<typename PixelT>
class lsst::meas::base::SincCoeffs< PixelT >

A singleton to calculate and cache the coefficients for sinc photometry.

Caching is only performed for circular apertures (because elliptical apertures are assumed to be generated dynamically, and hence not expected to recur). Caching must be explicitly requested for a particular circular aperture (using the 'cache' method).

Definition at line 45 of file SincCoeffs.h.

Member Typedef Documentation

CoeffT

template<typename PixelT >

typedef afw::image::Image<PixelT> lsst::meas::base::SincCoeffs< PixelT >::CoeffT

Definition at line 47 of file SincCoeffs.h.

Member Function Documentation

cache()

template<typename PixelT >

void lsst::meas::base::SincCoeffs< PixelT >::cache ( float rInner, float rOuter )

static

Cache the coefficients for a particular aperture.

The aperture is a circular annulus.

Definition at line 491 of file SincCoeffs.cc.

                                                 {
    if (r1 < 0.0 || r2 < r1) {
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          (boost::format("Invalid r1,r2 = %f,%f") % r1 % r2).str());
    }
    double const innerFactor = r1 / r2;
    afw::geom::ellipses::Axes axes(r2, r2, 0.0);
    if (!getInstance()._lookup(axes, innerFactor)) {
        std::shared_ptr<typename SincCoeffs<PixelT>::CoeffT> coeff = calculate(axes, innerFactor);
        getInstance()._cache[r2][innerFactor] = coeff;
    }
}

calculate()

template<typename PixelT >

std::shared_ptr< typename SincCoeffs< PixelT >::CoeffT > lsst::meas::base::SincCoeffs< PixelT >::calculate ( afw::geom::ellipses::Axes const & outerEllipse, double const innerFactor = 0.0 )

static

Calculate the coefficients for an aperture.

Definition at line 535 of file SincCoeffs.cc.

                                                                                       {
    if (innerFactor < 0.0 || innerFactor > 1.0) {
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          (boost::format("innerFactor = %f is not between 0 and 1") % innerFactor).str());
    }
 
    // Kspace-real is fastest, but only slightly faster than kspace cplx
    // but real won't work for elliptical apertures due to symmetries assumed for real transform
 
    double const rad1 = axes.getA() * innerFactor;
    double const rad2 = axes.getA();
    // if there's no angle and no ellipticity
    if (FuzzyCompare<float>().isEqual(axes.getA(), axes.getB())) {
        // here we call the real transform
        return calcImageKSpaceReal<PixelT>(rad1, rad2);
    } else {
        // here we call the complex transform
        double const ellipticity = 1.0 - axes.getB() / axes.getA();
        return calcImageKSpaceCplx<PixelT>(rad1, rad2, axes.getTheta(), ellipticity);
    }
}

get()

template<typename PixelT >

std::shared_ptr< typename SincCoeffs< PixelT >::CoeffT const > lsst::meas::base::SincCoeffs< PixelT >::get ( afw::geom::ellipses::Axes const & outerEllipse, float const innerRadiusFactor = 0.0 )

static

Get the coefficients for an aperture.

Coefficients are retrieved from the cache, if available; otherwise they will be generated.

Definition at line 506 of file SincCoeffs.cc.

                                                                                {
    std::shared_ptr<CoeffT const> coeff = getInstance()._lookup(axes, innerFactor);
    return coeff ? coeff : calculate(axes, innerFactor);
}

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/meas_base/gacf8899fa4+c69c5206e8/include/lsst/meas/base/SincCoeffs.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/meas_base/gacf8899fa4+c69c5206e8/src/SincCoeffs.cc