Small class to compute switching functions. More...

#include <SwitchingFunction.h>

Public Member Functions
double	calculate (double x, double &df) const
	Compute the switching function.

double	calculateSqr (double distance2, double &dfunc) const
	Compute the switching function.

std::string	description () const
	Returns a string with a description of the switching function.

double	get_d0 () const
	Returns d0.

const switchContainers::Data &	get_data () const
	Return the settings of the switching function.

double	get_dmax () const
	Return dmax.

double	get_dmax2 () const
	Return dmax squared.

double	get_r0 () const
	Returns r0.

void	removeFromACCDevice () const

void	set (const std::string &definition, std::string &errormsg)
	Set an arbitrary switching function.

void	set (int nn, int mm, double r_0, double d_0)
	Set a "rational" switching function.

void	toACCDevice () const

Static Public Member Functions
static void	registerKeywords (Keywords &keys)

Private Attributes
switchContainers::Data	switchData

switchContainers::switchType	type =switchContainers::switchType::not_initialized

Detailed Description

Small class to compute switching functions.

Switching functions are created using set() and then can be used with function calculate() or calculateSqr(). Since this is typically computed on a distance vector, the second all (calculateSqr()) allows to skip the calculation of a square root in some case, thus potentially increasing performances.

Member Function Documentation

◆ calculate()

double PLMD::SwitchingFunctionAccelerable::calculate	(	double	x,
		double &	df ) const

Compute the switching function.

Returns s(x). df will be set to the value of the derivative of the switching function _divided_by_x

◆ calculateSqr()

double PLMD::SwitchingFunctionAccelerable::calculateSqr	(	double	distance2,
		double &	dfunc ) const

Compute the switching function.

Returns \( s(\sqrt{x})\) . df will be set to the \( \frac{1}{\sqrt{x}}\frac{ds}{d\sqrt{x}}= 2 \frac{ds}{dx}\) (same as calculate()). The advantage is that in some case the expensive square root can be avoided (namely for rational functions, if nn and mm are even and d0 is zero)

◆ description()

std::string PLMD::SwitchingFunctionAccelerable::description ( ) const

Returns a string with a description of the switching function.

◆ get_d0()

double PLMD::SwitchingFunctionAccelerable::get_d0 ( ) const

Returns d0.

◆ get_data()

const switchContainers::Data & PLMD::SwitchingFunctionAccelerable::get_data ( ) const

Return the settings of the switching function.

◆ get_dmax()

double PLMD::SwitchingFunctionAccelerable::get_dmax ( ) const

Return dmax.

◆ get_dmax2()

double PLMD::SwitchingFunctionAccelerable::get_dmax2 ( ) const

Return dmax squared.

◆ get_r0()

double PLMD::SwitchingFunctionAccelerable::get_r0 ( ) const

Returns r0.

◆ registerKeywords()

void PLMD::SwitchingFunctionAccelerable::registerKeywords ( Keywords & keys )

static

◆ removeFromACCDevice()

void PLMD::SwitchingFunctionAccelerable::removeFromACCDevice ( ) const

◆ set() [1/2]

void PLMD::SwitchingFunctionAccelerable::set	(	const std::string &	definition,
		std::string &	errormsg )

Set an arbitrary switching function.

Parse the string in definition and possibly returns errors in the errormsg string

◆ set() [2/2]

void PLMD::SwitchingFunctionAccelerable::set	(	int	nn,
		int	mm,
		double	r_0,
		double	d_0 )

Set a "rational" switching function.

Notice that a d_max is set automatically to a value such that f(d_max)=0.00001.

◆ toACCDevice()

void PLMD::SwitchingFunctionAccelerable::toACCDevice ( ) const

Member Data Documentation

◆ switchData

switchContainers::Data PLMD::SwitchingFunctionAccelerable::switchData

private

◆ type

switchContainers::switchType PLMD::SwitchingFunctionAccelerable::type =switchContainers::switchType::not_initialized