lsst::gauss2d::fit::LogitLimitedTransform Class Reference

#include <transforms.h>

Inheritance diagram for lsst::gauss2d::fit::LogitLimitedTransform:

Public Member Functions
	LogitLimitedTransform (std::shared_ptr< parameters::Limits< double > > limits, double factor=1)
std::string	description () const override
	Return a description of this transform.
std::string	repr (bool name_keywords=false, const std::string_view &namespace_separator=parameters::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.
double	get_factor () const
parameters::Limits< double > &	get_limits () const
double	derivative (double x) const override
double	forward (double x) const override
double	reverse (double x) const override
void	set_factor (double factor)
void	set_limits (std::shared_ptr< parameters::Limits< double > > limits)
virtual T	derivative (T x) const =0
	Return the derivative of this tranform at the value x.
virtual T	forward (T x) const =0
	Return the transformed value of x.
virtual T	reverse (T x) const =0
	Return the original value of x given a transformed value.

Static Public Attributes
static constexpr std::string_view	CC_NAMESPACE_SEPARATOR = "::"
	The C++ namespace separator.

Detailed Description

Definition at line 111 of file transforms.h.

Constructor & Destructor Documentation

LogitLimitedTransform()

lsst::gauss2d::fit::LogitLimitedTransform::LogitLimitedTransform ( std::shared_ptr< parameters::Limits< double > > limits, double factor = 1 )

inlineexplicit

Definition at line 113 of file transforms.h.

                                                                                                      {
        set_limits(std::move(limits));
        set_factor(factor);
        _set_range();
    }

Member Function Documentation

derivative() [1/2]

double lsst::gauss2d::fit::LogitLimitedTransform::derivative ( double x ) const

override

Definition at line 10 of file transforms.cc.

                                                       {
    double y = (x - _limits->get_min()) / _range;
    if (y == 1)
        return INF;
    else if (y == 0)
        return -INF;
    return (1 / y + 1 / (1 - y)) * _factor / _range;
}

derivative() [2/2]

template<class T >

virtual T lsst::modelfit::parameters::Transform< T >::derivative ( T x ) const

pure virtualinherited

Return the derivative of this tranform at the value x.

Implemented in lsst::modelfit::parameters::UnitTransform< T >.

description()

std::string lsst::gauss2d::fit::LogitLimitedTransform::description ( ) const

inlineoverridevirtual

Return a description of this transform.

Implements lsst::modelfit::parameters::Transform< T >.

Definition at line 119 of file transforms.h.

{ return "Logit limited (to finite range) transform"; }

forward() [1/2]

double lsst::gauss2d::fit::LogitLimitedTransform::forward ( double x ) const

override

Definition at line 19 of file transforms.cc.

                                                    {
    double min = _limits->get_min();
    double max = _limits->get_max();
    if (x == min)
        return -std::numeric_limits<double>::infinity();
    else if (x == max)
        return std::numeric_limits<double>::infinity();
    double y = (x - min) / _range;
    if (!(y < 1) || !(y > 0)) return nan("");
    return log(y / (1 - y)) * _factor;
}

forward() [2/2]

template<class T >

virtual T lsst::modelfit::parameters::Transform< T >::forward ( T x ) const

pure virtualinherited

Return the transformed value of x.

Implemented in lsst::modelfit::parameters::UnitTransform< T >.

get_factor()

double lsst::gauss2d::fit::LogitLimitedTransform::get_factor ( ) const

inline

Definition at line 132 of file transforms.h.

{ return _factor; }

get_limits()

parameters::Limits< double > & lsst::gauss2d::fit::LogitLimitedTransform::get_limits ( ) const

inline

Definition at line 133 of file transforms.h.

{ return *_limits; }

repr()

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

inlineoverridevirtual

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.

Implements lsst::modelfit::parameters::Object.

Definition at line 120 of file transforms.h.

                                                                              {
        return parameters::type_name_str<LogitLimitedTransform>(false, namespace_separator) + "("
               + (name_keywords ? "limits=" : "") + _limits->repr(name_keywords, namespace_separator) + ", "
               + (name_keywords ? "factor=" : "") + std::to_string(_factor) + ")";
    }

reverse() [1/2]

double lsst::gauss2d::fit::LogitLimitedTransform::reverse ( double x ) const

override

Definition at line 31 of file transforms.cc.

                                                    {
    double y = -x * _factor;
    // math.log(np.finfo(np.float64) = 709.782712893384
    // things will go badly well before then
    if (y > 709.7827) return _limits->get_min();
    y = 1 + exp(y);
    return _range / y + _limits->get_min();
}

reverse() [2/2]

template<class T >

virtual T lsst::modelfit::parameters::Transform< T >::reverse ( T x ) const

pure virtualinherited

Return the original value of x given a transformed value.

Implemented in lsst::modelfit::parameters::UnitTransform< T >.

set_factor()

void lsst::gauss2d::fit::LogitLimitedTransform::set_factor ( double factor )

inline

Definition at line 139 of file transforms.h.

                                   {
        if (!(factor > 0))
            throw std::invalid_argument("LogitLimitedTransform factor=" + std::to_string(factor) + " !>0");
        _factor = factor;
    }

set_limits()

void lsst::gauss2d::fit::LogitLimitedTransform::set_limits ( std::shared_ptr< parameters::Limits< double > > limits )

inline

Definition at line 145 of file transforms.h.

                                                                    {
        _limits = (limits == nullptr) ? std::make_shared<parameters::Limits<double>>() : std::move(limits);
        _set_range();
    }

str()

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

inlineoverridevirtual

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

Implements lsst::modelfit::parameters::Object.

Definition at line 127 of file transforms.h.

                                   {
        return parameters::type_name_str<LogitLimitedTransform>(true) + "(limits=" + _limits->str()
               + ", factor=" + std::to_string(_factor) + ")";
    }

Member Data Documentation

CC_NAMESPACE_SEPARATOR

constexpr std::string_view lsst::modelfit::parameters::Object::CC_NAMESPACE_SEPARATOR = "::"

staticconstexprinherited

The C++ namespace separator.

Definition at line 42 of file object.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/gauss2d_fit/gb58c049af0+ace264a4f2/include/lsst/gauss2d/fit/transforms.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/gauss2d_fit/gb58c049af0+ace264a4f2/src/transforms.cc