flexiblesusy::Root_finder< dimension > Class Template Reference

Function root finder. More...

#include <root_finder.hpp>

Inheritance diagram for flexiblesusy::Root_finder< dimension >:

Collaboration diagram for flexiblesusy::Root_finder< dimension >:

Public Types
using	Function_t = std::function< Vector_t(const Vector_t &)>
enum	Solver_type { GSLHybrid , GSLHybridS , GSLBroyden , GSLNewton }
using	Vector_t = Eigen::Matrix< double, dimension, 1 >
Public Types inherited from flexiblesusy::EWSB_solver
enum	Status : int { SUCCESS = 0 , FAIL = 1 }

Public Member Functions
int	find_root (const Vector_t &)
virtual Eigen::VectorXd	get_solution () const override
virtual std::string	name () const override
	Root_finder ()=default
	Root_finder (const Function_t &, std::size_t, double, Solver_type solver_type_=GSLHybrid)
void	set_function (const Function_t &f)
void	set_max_iterations (std::size_t n)
void	set_precision (double p)
void	set_solver_type (Solver_type t)
virtual int	solve (const Eigen::VectorXd &) override
virtual	~Root_finder ()=default
Public Member Functions inherited from flexiblesusy::EWSB_solver
virtual Eigen::VectorXd	get_solution () const =0
virtual std::string	name () const =0
virtual int	solve (const Eigen::VectorXd &)=0
virtual	~EWSB_solver ()=default

Private Member Functions
const char *	solver_type_name () const
const gsl_multiroot_fsolver_type *	solver_type_to_gsl_pointer () const

Static Private Member Functions
static int	gsl_function (const gsl_vector *, void *, gsl_vector *)
static bool	is_finite (const Vector_t &v)

Private Attributes
Function_t	function {nullptr}
	function to minimize More...
std::size_t	max_iterations {100}
	maximum number of iterations More...
double	precision {1.e-2}
	precision goal More...
Vector_t	root {Vector_t::Zero()}
	the root More...
Solver_type	solver_type {GSLHybrid}
	solver type More...

Detailed Description

template<std::size_t dimension>
class flexiblesusy::Root_finder< dimension >

Function root finder.

The user has to provide the function (of which the root should be found) of the type Function_t. This function gets as arguments an Eigen vector of lenght ‘dimension’ and returns an Eigen vector of the same length.

Example:

auto parabola = [](const Eigen::Matrix<double,2,1>& x) {
   const double y = x(0);
   const double z = x(1);
   Eigen::Matrix<double,2,1> f;
   f << y*(y - 5.0), z*(z - 1.0);
   return f;
};
 
Root_finder<2> root_finder(parabola, 100, 1.0e-5);
const double start[2] = { 10, 10 };
const int status = root_finder.find_root(start);

Definition at line 64 of file root_finder.hpp.

Member Typedef Documentation

Function_t

template<std::size_t dimension>

using flexiblesusy::Root_finder< dimension >::Function_t = std::function<Vector_t(const Vector_t&)>

Definition at line 67 of file root_finder.hpp.

Vector_t

template<std::size_t dimension>

using flexiblesusy::Root_finder< dimension >::Vector_t = Eigen::Matrix<double,dimension,1>

Definition at line 66 of file root_finder.hpp.

Member Enumeration Documentation

Solver_type

template<std::size_t dimension>

enum flexiblesusy::Root_finder::Solver_type

Enumerator
GSLHybrid
GSLHybridS
GSLBroyden
GSLNewton

Definition at line 68 of file root_finder.hpp.

Constructor & Destructor Documentation

Root_finder() [1/2]

template<std::size_t dimension>

flexiblesusy::Root_finder< dimension >::Root_finder ( )

default

Root_finder() [2/2]

template<std::size_t dimension>

flexiblesusy::Root_finder< dimension >::Root_finder	(	const Function_t &	function_,
		std::size_t	max_iterations_,
		double	precision_,
		Solver_type	solver_type_ = GSLHybrid
	)

Constructor

Parameters

function_	pointer to the function to minimize
max_iterations_	maximum number of iterations
precision_	precision goal
solver_type_	GSL multiroot solver type

Definition at line 111 of file root_finder.hpp.

~Root_finder()

template<std::size_t dimension>

virtual flexiblesusy::Root_finder< dimension >::~Root_finder ( )

virtualdefault

Member Function Documentation

find_root()

template<std::size_t dimension>

int flexiblesusy::Root_finder< dimension >::find_root

(

const Vector_t &

start

)

Start the minimization

Parameters

start

starting point

Returns

GSL error code (GSL_SUCCESS if minimum found)

Definition at line 132 of file root_finder.hpp.

References flexiblesusy::f(), flexiblesusy::GSL_multiroot_fsolver::get_root(), flexiblesusy::GSL_multiroot_fsolver::iterate(), parameters(), flexiblesusy::GSL_multiroot_fsolver::print_state(), flexiblesusy::GSL_vector::raw(), flexiblesusy::GSL_multiroot_fsolver::test_residual(), flexiblesusy::to_GSL_vector(), and VERBOSE_MSG.

get_solution()

template<std::size_t dimension>

virtual Eigen::VectorXd flexiblesusy::Root_finder< dimension >::get_solution ( ) const

inlineoverridevirtual

Implements flexiblesusy::EWSB_solver.

Definition at line 83 of file root_finder.hpp.

References flexiblesusy::Root_finder< dimension >::root.

gsl_function()

template<std::size_t dimension>

int flexiblesusy::Root_finder< dimension >::gsl_function ( const gsl_vector *  x, void *  params, gsl_vector *  f  )

staticprivate

Definition at line 166 of file root_finder.hpp.

References flexiblesusy::arg(), flexiblesusy::f(), and flexiblesusy::is_finite().

is_finite()

template<std::size_t dimension>

static bool flexiblesusy::Root_finder< dimension >::is_finite ( const Vector_t &  v )

inlinestaticprivate

Definition at line 96 of file root_finder.hpp.

name()

template<std::size_t dimension>

virtual std::string flexiblesusy::Root_finder< dimension >::name ( ) const

inlineoverridevirtual

Implements flexiblesusy::EWSB_solver.

Definition at line 81 of file root_finder.hpp.

References flexiblesusy::Root_finder< dimension >::solver_type_name().

set_function()

template<std::size_t dimension>

void flexiblesusy::Root_finder< dimension >::set_function ( const Function_t &  f )

inline

Definition at line 74 of file root_finder.hpp.

References flexiblesusy::f(), and flexiblesusy::Root_finder< dimension >::function.

set_max_iterations()

template<std::size_t dimension>

void flexiblesusy::Root_finder< dimension >::set_max_iterations ( std::size_t  n )

inline

Definition at line 76 of file root_finder.hpp.

References flexiblesusy::Root_finder< dimension >::max_iterations.

set_precision()

template<std::size_t dimension>

void flexiblesusy::Root_finder< dimension >::set_precision ( double  p )

inline

Definition at line 75 of file root_finder.hpp.

References flexiblesusy::Root_finder< dimension >::precision.

set_solver_type()

template<std::size_t dimension>

void flexiblesusy::Root_finder< dimension >::set_solver_type ( Solver_type  t )

inline

Definition at line 77 of file root_finder.hpp.

References flexiblesusy::Root_finder< dimension >::solver_type.

solve()

template<std::size_t dimension>

int flexiblesusy::Root_finder< dimension >::solve ( const Eigen::VectorXd &  start )

overridevirtual

Implements flexiblesusy::EWSB_solver.

Definition at line 227 of file root_finder.hpp.

References flexiblesusy::EWSB_solver::FAIL, and flexiblesusy::EWSB_solver::SUCCESS.

solver_type_name()

template<std::size_t dimension>

const char * flexiblesusy::Root_finder< dimension >::solver_type_name

private

Definition at line 195 of file root_finder.hpp.

References flexiblesusy::to_string().

Referenced by flexiblesusy::Root_finder< dimension >::name().

solver_type_to_gsl_pointer()

template<std::size_t dimension>

const gsl_multiroot_fsolver_type * flexiblesusy::Root_finder< dimension >::solver_type_to_gsl_pointer

private

Definition at line 211 of file root_finder.hpp.

References flexiblesusy::to_string().

Member Data Documentation

function

template<std::size_t dimension>

Function_t flexiblesusy::Root_finder< dimension >::function {nullptr}

private

function to minimize

Definition at line 89 of file root_finder.hpp.

Referenced by flexiblesusy::Root_finder< dimension >::set_function().

max_iterations

template<std::size_t dimension>

std::size_t flexiblesusy::Root_finder< dimension >::max_iterations {100}

private

maximum number of iterations

Definition at line 86 of file root_finder.hpp.

Referenced by flexiblesusy::Root_finder< dimension >::set_max_iterations().

precision

template<std::size_t dimension>

double flexiblesusy::Root_finder< dimension >::precision {1.e-2}

private

precision goal

Definition at line 87 of file root_finder.hpp.

Referenced by flexiblesusy::Root_finder< dimension >::set_precision().

root

template<std::size_t dimension>

Vector_t flexiblesusy::Root_finder< dimension >::root {Vector_t::Zero()}

private

the root

Definition at line 88 of file root_finder.hpp.

Referenced by flexiblesusy::Root_finder< dimension >::get_solution().

solver_type

template<std::size_t dimension>

Solver_type flexiblesusy::Root_finder< dimension >::solver_type {GSLHybrid}

private

solver type

Definition at line 90 of file root_finder.hpp.

Referenced by flexiblesusy::Root_finder< dimension >::set_solver_type().

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

• root_finder.hpp