lsst::gauss2d::fit::SersicMixComponent Class Reference

A Gaussian mixture approximation to a Sersic profile Component. More...

#include <sersicmixcomponent.h>

Inheritance diagram for lsst::gauss2d::fit::SersicMixComponent:

Classes
class	SersicMixGaussianComponent

Public Member Functions
	SersicMixComponent (std::shared_ptr< SersicParametricEllipse > ellipse=nullptr, std::shared_ptr< CentroidParameters > centroid=nullptr, std::shared_ptr< IntegralModel > integralmodel=nullptr, std::shared_ptr< SersicMixComponentIndexParameterD > sersicindex=nullptr)
	~SersicMixComponent ()
void	add_extra_param_map (const Channel &channel, ExtraParamMap &map_extra, const GradParamMap &map_grad, ParameterMap &offsets) const override
	Add extra Parameter indices to a map.
void	add_extra_param_factors (const Channel &channel, ExtraParamFactors &factors) const override
	Add extra Parameter gradient factors to an existing vector.
void	add_grad_param_map (const Channel &channel, GradParamMap &map, ParameterMap &offsets) const override
	Add Parameter gradient indices to an existing map.
void	add_grad_param_factors (const Channel &channel, GradParamFactors &factor) const override
	Add Parameter gradient factors to an existing map.
std::unique_ptr< const lsst::gauss2d::Gaussians >	get_gaussians (const Channel &channel) const override
	Return the vector of Gaussian sub-components controlled by this model.
size_t	get_n_gaussians (const Channel &channel) const override
	Return the number of Gaussian sub-components controlled by this model.
ParamRefs &	get_parameters (ParamRefs &params, ParamFilter *filter=nullptr) const override
	Add Parameter refs matching the filter to a vector, in order.
ParamCRefs &	get_parameters_const (ParamCRefs &params, ParamFilter *filter=nullptr) const override
	Same as get_parameters(), but for const refs.
double	get_sersicindex () const
SersicMixComponentIndexParameterD &	get_sersicindex_param () const
std::shared_ptr< SersicMixComponentIndexParameterD >	get_sersicindex_param_ptr ()
void	set_extra_param_factors (const Channel &channel, ExtraParamFactors &factors, size_t index) const override
	Set extra Parameter gradient factors in an existing map.
void	set_grad_param_factors (const Channel &channel, GradParamFactors &factors, size_t index) const override
	Set Parameter gradient factors in an existing map.
void	set_sersicindex (double value)
std::string	repr (bool name_keywords=false, std::string_view namespace_separator=Object::CC_NAMESPACE_SEPARATOR) const override
	Return a full, callable string representation of this.
std::string	str () const override
	Return a brief, human-readable string representation of this.
const CentroidParameters &	get_centroid () const
	Get the centroid Parameter container.
const ParametricEllipse &	get_ellipse () const
	Get the ellipse Parameter container.
const IntegralModel &	get_integralmodel () const override
ParamRefs	get_parameters_new (ParamFilter *filter=nullptr) const
	Same as get_parameters(), but returning a new vector.
ParamCRefs	get_parameters_const_new (ParamFilter *filter=nullptr) const
	Same as get_parameters_const(), but returning a new vector.

Static Public Member Functions
static std::string_view	null_str (const std::string_view &namespace_separator)

Static Public Attributes
static const size_t	N_PARAMS = N_PARAMS_GAUSS2D + 1
static constexpr std::string_view	CC_NAMESPACE_SEPARATOR = "::"
	The C++ namespace separator.
static constexpr std::string_view	NULL_STR_GENERAL = "None"
static constexpr std::string_view	PY_NAMESPACE_SEPARATOR = "."

Protected Attributes
std::shared_ptr< ParametricEllipse >	_ellipse
std::shared_ptr< CentroidParameters >	_centroid
std::shared_ptr< IntegralModel >	_integralmodel

Detailed Description

A Gaussian mixture approximation to a Sersic profile Component.

This Component approximates the Sersic (1968) profile, which is a widely-used (in astronomy) exponentially-declining radial profile with a single shape parameter. It is also functionally a generalization of the Gaussian (Sersic index n=0.5), exponential (n=1) and de Vaucouleurs (1948) (n=4) profiles.

This particular implementation closely matches the majority of the profile, but deliberately excludes the very inner and outermost regions.

Note

See Graham & Driver 2005 for a useful summary of various properties of the Sersic profile.

Definition at line 85 of file sersicmixcomponent.h.

Constructor & Destructor Documentation

SersicMixComponent()

lsst::gauss2d::fit::SersicMixComponent::SersicMixComponent ( std::shared_ptr< SersicParametricEllipse > ellipse = nullptr, std::shared_ptr< CentroidParameters > centroid = nullptr, std::shared_ptr< IntegralModel > integralmodel = nullptr, std::shared_ptr< SersicMixComponentIndexParameterD > sersicindex = nullptr )

explicit

Definition at line 270 of file sersicmixcomponent.cc.

        : SersicParametricEllipseHolder(std::move(ellipse)),
          EllipticalComponent(_ellipsedata, centroid, integralmodel),
          _sersicindex(sersicindex != nullptr ? std::move(sersicindex)
                                              : std::make_shared<SersicMixComponentIndexParameterD>()) {
    for (const Channel& channel : _integralmodel->get_channels()) {
        auto& gaussians = _gaussians[channel];
        gaussians.reserve(_sersicindex->get_order());
        for (size_t index = 0; index < _sersicindex->get_order(); ++index) {
            auto ell = std::make_shared<SersicEllipseData>(
                    _ellipsedata->get_reff_x_param_ptr(), _ellipsedata->get_reff_y_param_ptr(),
                    _ellipsedata->get_rho_param_ptr(), _sersicindex, index);
            auto integral
                    = std::make_shared<SersicModelIntegral>(channel, _integralmodel, _sersicindex, index);
            gaussians.emplace_back(
                    std::make_unique<SersicMixGaussianComponent>(ell, this->_centroid, integral));
        }
    };
}

~SersicMixComponent()

lsst::gauss2d::fit::SersicMixComponent::~SersicMixComponent

(

)

Definition at line 293 of file sersicmixcomponent.cc.

{};

Member Function Documentation

add_extra_param_factors()

void lsst::gauss2d::fit::SersicMixComponent::add_extra_param_factors ( const Channel & channel, ExtraParamFactors & factors ) const

overridevirtual

Add extra Parameter gradient factors to an existing vector.

Parameters

channel	The Channel to add factors for.
factors	The ExtraParamFactors to add to.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 320 of file sersicmixcomponent.cc.

                                                                                                         {
    for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
        factors.push_back({0, 0, 0});
    }
}

add_extra_param_map()

void lsst::gauss2d::fit::SersicMixComponent::add_extra_param_map ( const Channel & channel, ExtraParamMap & map_extra, const GradParamMap & map_grad, ParameterMap & offsets ) const

overridevirtual

Add extra Parameter indices to a map.

Parameters

channel	The Channel to add indices for.
map_extra	The ExtraParamMap to add to.
map_grad	The completed GradParamMap.
offsets	A map of index offsets for Parameters that have already been added.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 295 of file sersicmixcomponent.cc.

                                                                                                        {
    if (_sersicindex->get_free()) {
        auto found = offsets.find(*_sersicindex);
        if (found == offsets.end()) {
            throw std::runtime_error("_sersicindex=" + _sersicindex->str()
                                     + " not found in offsets; was add_grad_param_map called?");
        }
        const auto& offset = (*found).second;
        const size_t order = _sersicindex->get_order();
        const size_t size_map_grad = map_grad.size();
        if (!(size_map_grad >= order)) {
            throw std::invalid_argument("map_grad.size()=" + std::to_string(map_grad.size())
                                        + "!>=order=" + std::to_string(order));
        }
        for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
            map_extra.push_back({size_map_grad - order + idx_g, offset});
        }
    } else {
        for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
            map_extra.push_back({0, 0});
        }
    }
}

add_grad_param_factors()

void lsst::gauss2d::fit::SersicMixComponent::add_grad_param_factors ( const Channel & channel, GradParamFactors & factors ) const

overridevirtual

Add Parameter gradient factors to an existing map.

Parameters

channel	The Channel to add factors for.
factors	The GradParamFactors to add to.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 364 of file sersicmixcomponent.cc.

                                                                                                       {
    ParamCRefs params;
    ParamFilter filter{};
    filter.channel = channel;
    this->get_parameters_const(params, &filter);
 
    if (params.size() != N_PARAMS) {
        throw std::runtime_error(this->str() + "get_parameters_const with channel=" + channel.str() + " size="
                                 + std::to_string(params.size()) + "!=N_PARAMS=" + std::to_string(N_PARAMS));
    }
 
    for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
        std::array<double, N_PARAMS_GAUSS2D> values{1., 1., 1., 1., 1., 1.};
        factors.push_back(values);
    }
}

add_grad_param_map()

void lsst::gauss2d::fit::SersicMixComponent::add_grad_param_map ( const Channel & channel, GradParamMap & map, ParameterMap & offsets ) const

overridevirtual

Add Parameter gradient indices to an existing map.

Parameters

channel	The Channel to add indices for.
map	The map to add to.
offsets	A map of index offsets for Parameters that have already been added.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 326 of file sersicmixcomponent.cc.

                                                                         {
    ParamCRefs params;
    ParamFilter filter{};
    filter.channel = channel;
    this->get_parameters_const(params, &filter);
 
    if (params.size() != N_PARAMS) {
        throw std::runtime_error(this->str() + "get_parameters_const with channel=" + channel.str() + " size="
                                 + std::to_string(params.size()) + "!=N_PARAMS=" + std::to_string(N_PARAMS));
    }
 
    std::array<size_t, N_PARAMS_GAUSS2D> values{0, 0, 0, 0, 0, 0};
 
    size_t size_map = offsets.size();
    size_t index_param_map;
    for (size_t idx_param = 0; idx_param < N_PARAMS_GAUSS2D; ++idx_param) {
        const size_t& order_param = IDX_ORDER[idx_param];
        // The parameters must be in the same order as returned by get_parameters(_const)
        const auto& param = params.at(idx_param).get();
        if (!param.get_fixed()) {
            if (offsets.find(param) == offsets.end()) {
                index_param_map = ++size_map;
                offsets[param] = index_param_map;
            } else {
                index_param_map = offsets[param];
            }
            values[order_param] = index_param_map;
        }
    }
    if (_sersicindex->get_free() && (offsets.find(*_sersicindex) == offsets.end())) {
        offsets[params[N_PARAMS_GAUSS2D]] = offsets.size() + 1;
    }
    for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
        map.push_back(values);
    }
}

get_centroid()

const CentroidParameters & lsst::gauss2d::fit::EllipticalComponent::get_centroid ( ) const

inherited

Get the centroid Parameter container.

Definition at line 23 of file ellipticalcomponent.cc.

{ return *_centroid; }

get_ellipse()

const ParametricEllipse & lsst::gauss2d::fit::EllipticalComponent::get_ellipse ( ) const

inherited

Get the ellipse Parameter container.

Definition at line 24 of file ellipticalcomponent.cc.

{ return *_ellipse; }

get_gaussians()

std::unique_ptr< const lsst::gauss2d::Gaussians > lsst::gauss2d::fit::SersicMixComponent::get_gaussians ( const Channel & channel ) const

overridevirtual

Return the vector of Gaussian sub-components controlled by this model.

Parameters

channel

The Channel to return Gaussians for.

Returns

The Gaussians controlled by this model.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 381 of file sersicmixcomponent.cc.

                                      {
    std::vector<std::optional<const lsst::gauss2d::Gaussians::Data>> in;
    // TODO: This isn't sufficient; need to implement get_n_components
    const auto& components = _gaussians.at(channel);
    in.reserve(components.size());
    for (auto& component : components) {
        in.push_back(component->get_gaussians(channel)->get_data());
    }
    return std::make_unique<lsst::gauss2d::Gaussians>(in);
}

get_integralmodel()

const IntegralModel & lsst::gauss2d::fit::EllipticalComponent::get_integralmodel ( ) const

overridevirtualinherited

Implements lsst::gauss2d::fit::Component.

Definition at line 25 of file ellipticalcomponent.cc.

{ return *_integralmodel; }

get_n_gaussians()

size_t lsst::gauss2d::fit::SersicMixComponent::get_n_gaussians ( const Channel & channel ) const

overridevirtual

Return the number of Gaussian sub-components controlled by this model.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 393 of file sersicmixcomponent.cc.

                                                                       {
    return _gaussians.at(channel).size();
};

get_parameters()

ParamRefs & lsst::gauss2d::fit::SersicMixComponent::get_parameters ( ParamRefs & params, ParamFilter * filter = nullptr ) const

overridevirtual

Add Parameter refs matching the filter to a vector, in order.

Parameters

params	The vector to add to.
filter	The filter to apply to this Object's parameters.

Returns

A ref to params (for method chaining)

Reimplemented from lsst::gauss2d::fit::EllipticalComponent.

Definition at line 397 of file sersicmixcomponent.cc.

                                                                                          {
    EllipticalComponent::get_parameters(params, filter);
    insert_param(*_sersicindex, params, filter);
    return params;
}

get_parameters_const()

ParamCRefs & lsst::gauss2d::fit::SersicMixComponent::get_parameters_const ( ParamCRefs & params, ParamFilter * filter = nullptr ) const

overridevirtual

Same as get_parameters(), but for const refs.

Reimplemented from lsst::gauss2d::fit::EllipticalComponent.

Definition at line 403 of file sersicmixcomponent.cc.

                                                                                                  {
    EllipticalComponent::get_parameters_const(params, filter);
    insert_param(*_sersicindex, params, filter);
    return params;
}

get_parameters_const_new()

ParamCRefs lsst::gauss2d::fit::Parametric::get_parameters_const_new ( ParamFilter * filter = nullptr ) const

inlineinherited

Same as get_parameters_const(), but returning a new vector.

Definition at line 33 of file parametric.h.

                                                                             {
        ParamCRefs params{};
        get_parameters_const(params, filter);
        return params;
    }

get_parameters_new()

ParamRefs lsst::gauss2d::fit::Parametric::get_parameters_new ( ParamFilter * filter = nullptr ) const

inlineinherited

Same as get_parameters(), but returning a new vector.

Definition at line 27 of file parametric.h.

                                                                      {
        ParamRefs params{};
        get_parameters(params, filter);
        return params;
    }

get_sersicindex()

double lsst::gauss2d::fit::SersicMixComponent::get_sersicindex

(

)

const

Definition at line 409 of file sersicmixcomponent.cc.

{ return this->_sersicindex->get_value(); }

get_sersicindex_param()

SersicMixComponentIndexParameterD & lsst::gauss2d::fit::SersicMixComponent::get_sersicindex_param

(

)

const

Definition at line 411 of file sersicmixcomponent.cc.

                                                                                   {
    return *(this->_sersicindex);
}

get_sersicindex_param_ptr()

std::shared_ptr< SersicMixComponentIndexParameterD > lsst::gauss2d::fit::SersicMixComponent::get_sersicindex_param_ptr

(

)

Definition at line 415 of file sersicmixcomponent.cc.

                                                                                               {
    return this->_sersicindex;
}

null_str()

static std::string_view lsst::gauss2d::Object::null_str ( const std::string_view & namespace_separator )

inlinestaticinherited

Definition at line 49 of file object.h.

                                                                              {
        return namespace_separator == CC_NAMESPACE_SEPARATOR ? "nullptr" : NULL_STR_GENERAL;
    }

repr()

std::string lsst::gauss2d::fit::SersicMixComponent::repr ( bool name_keywords = false, std::string_view namespace_separator = Object::CC_NAMESPACE_SEPARATOR ) const

overridevirtual

Return a full, callable string representation of this.

Parameters

name_keywords	Whether to prefix arguments with "{name}=", where name is the arg name in the header (as with keyword arguments in Python).
namespace_separator	The string to use to delimit namespaces, i.e. :: in C++ and . in Python.

Returns

A callable string representation of this, which should return an an identical object to this.

Note

The representation with name_keywords=false must be callable in C++. The representation with name_keywords=true should be callable in Python, if there are any bindings.

Reimplemented from lsst::gauss2d::fit::EllipticalComponent.

Definition at line 484 of file sersicmixcomponent.cc.

                                                                                               {
    return type_name_str<SersicMixComponent>(false, namespace_separator) + "("
           + EllipticalComponent::repr(name_keywords, namespace_separator) + ", "
           + (name_keywords ? "sersicindex=" : "") + _sersicindex->repr(name_keywords, namespace_separator)
           + ")";
}

set_extra_param_factors()

void lsst::gauss2d::fit::SersicMixComponent::set_extra_param_factors ( const Channel & channel, ExtraParamFactors & factors, size_t index ) const

overridevirtual

Set extra Parameter gradient factors in an existing map.

Parameters

channel	The Channel to set factors for.
factors	The ExtraParamFactors to set factors for.
index	The index to begin setting factors at.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 419 of file sersicmixcomponent.cc.

                                                                     {
    if (_sersicindex->get_free()) {
        const auto& integralmodel = this->get_integralmodel();
        double dx = 1. / _sersicindex->get_transform_derivative();
        const double dintegral = dx * integralmodel.get_integral(channel);
        const double dreff_x = dx * _ellipse->get_size_x_param().get_size();
        const double dreff_y = dx * _ellipse->get_size_y_param().get_size();
        for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
            const double dsizeratio = _sersicindex->get_sizeratio_deriv(idx_g);
            auto& values = factors.at(index + idx_g);
            values[0] = dintegral * _sersicindex->get_integralratio_deriv(idx_g);
            values[1] = dreff_x * dsizeratio;
            values[2] = dreff_y * dsizeratio;
        }
    } else {
        for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
            auto& values = factors[index + idx_g];
            values[0] = 0;
            values[1] = 0;
            values[2] = 0;
        }
    }
}

set_grad_param_factors()

void lsst::gauss2d::fit::SersicMixComponent::set_grad_param_factors ( const Channel & channel, GradParamFactors & factors, size_t index ) const

overridevirtual

Set Parameter gradient factors in an existing map.

Parameters

channel	The Channel to set factors for.
factors	The GradParamFactors to set factors for.
index	The index to begin setting factors at.

Implements lsst::gauss2d::fit::ParametricModel.

Definition at line 444 of file sersicmixcomponent.cc.

                                                                    {
    ParamCRefs params;
    ParamFilter filter{};
    filter.channel = channel;
    this->get_parameters_const(params, &filter);
 
    std::array<double, N_PARAMS_GAUSS2D> values_base{1., 1., 1., 1., 1., 1.};
 
    for (size_t idx_param = 0; idx_param < N_PARAMS_GAUSS2D; ++idx_param) {
        const size_t& order_param = IDX_ORDER[idx_param];
        // The parameters must be in the same order as returned by get_parameters(_const)
        const auto& param = params.at(idx_param).get();
        if (param.get_fixed()) {
            values_base[order_param] = 0;
        } else {
            const auto deriv = param.get_transform_derivative();
            if (deriv == 0)
                throw std::runtime_error("Param[idx=" + std::to_string(idx_param) + "]=" + param.str()
                                         + " get_transform_derivative=0 (will result in divide by 0)");
            values_base[order_param] /= deriv;
        }
    }
 
    const auto& subcomps = _gaussians.at(channel);
    for (size_t idx_g = 0; idx_g < _sersicindex->get_order(); ++idx_g) {
        const auto& subcomp = subcomps[idx_g];
        auto& values = factors[index + idx_g];
        values[0] = values_base[0];
        values[1] = values_base[1];
        values[2] = values_base[2] * subcomp->get_integralmodel().get_integralratio();
        const double sizeratio = subcomp->get_ellipse().get_sizeratio();
        values[3] = values_base[3] * sizeratio;
        values[4] = values_base[4] * sizeratio;
        values[5] = values_base[5];
    }
}

set_sersicindex()

void lsst::gauss2d::fit::SersicMixComponent::set_sersicindex

(

double

value

)

Definition at line 482 of file sersicmixcomponent.cc.

{ this->_sersicindex->set_value(value); }

str()

std::string lsst::gauss2d::fit::SersicMixComponent::str ( ) const

overridevirtual

Return a brief, human-readable string representation of this.

Reimplemented from lsst::gauss2d::fit::EllipticalComponent.

Definition at line 491 of file sersicmixcomponent.cc.

                                        {
    return type_name_str<SersicMixComponent>(true) + "(" + EllipticalComponent::str()
           + ", sersicindex=" + _sersicindex->str() + ")";
}

Member Data Documentation

_centroid

std::shared_ptr<CentroidParameters> lsst::gauss2d::fit::EllipticalComponent::_centroid

protectedinherited

Definition at line 42 of file ellipticalcomponent.h.

_ellipse

std::shared_ptr<ParametricEllipse> lsst::gauss2d::fit::EllipticalComponent::_ellipse

protectedinherited

Definition at line 41 of file ellipticalcomponent.h.

_integralmodel

std::shared_ptr<IntegralModel> lsst::gauss2d::fit::EllipticalComponent::_integralmodel

protectedinherited

Definition at line 43 of file ellipticalcomponent.h.

CC_NAMESPACE_SEPARATOR

std::string_view lsst::gauss2d::Object::CC_NAMESPACE_SEPARATOR = "::"

staticconstexprinherited

The C++ namespace separator.

Definition at line 45 of file object.h.

N_PARAMS

const size_t lsst::gauss2d::fit::SersicMixComponent::N_PARAMS = N_PARAMS_GAUSS2D + 1

static

Definition at line 110 of file sersicmixcomponent.h.

NULL_STR_GENERAL

std::string_view lsst::gauss2d::Object::NULL_STR_GENERAL = "None"

staticconstexprinherited

Definition at line 46 of file object.h.

PY_NAMESPACE_SEPARATOR

std::string_view lsst::gauss2d::Object::PY_NAMESPACE_SEPARATOR = "."

staticconstexprinherited

Definition at line 47 of file object.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.1.0/Linux/gauss2d_fit/g199a45376c+5137f08352/include/lsst/gauss2d/fit/sersicmixcomponent.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.1.0/Linux/gauss2d_fit/g199a45376c+5137f08352/src/sersicmixcomponent.cc