SSAGES::RationalSwitchPK Class Reference

Rational Switching Function. More...

#include <PairwiseKernel.h>

Inheritance diagram for SSAGES::RationalSwitchPK:

Public Member Functions
	RationalSwitchPK (double d0, double r0, int n, int m)
	Constructor. More...
double	Evaluate (double rij, double &df) const override
	Evaluate the pairwise kernel function. More...
Public Member Functions inherited from SSAGES::PairwiseKernel
virtual	~PairwiseKernel ()
	Destructor.

Static Public Member Functions
static RationalSwitchPK *	Build (const Json::Value &json, const std::string &path)
	Build RationalSwitchPK from JSON value. More...
Static Public Member Functions inherited from SSAGES::PairwiseKernel
static PairwiseKernel *	Build (const Json::Value &json, const std::string &path)
	Build PairwiseKernel from JSON value. More...

Private Attributes
double	d0_
	Minimum linear shift value.
double	r0_
	Cutoff distance.
int	n_
	Exponent of numerator in switching function (controls stiffness).
int	m_
	Exponent of denominator in switching function (controls stiffness).

Detailed Description

Rational Switching Function.

A switching function of a rational form.

Definition at line 120 of file PairwiseKernel.h.

Constructor & Destructor Documentation

RationalSwitchPK()

SSAGES::RationalSwitchPK::RationalSwitchPK ( double  d0, double  r0, int  n, int  m  )

inline

Constructor.

Parameters

d0	Minimum linear shift value.
r0	Cutoff distance.
m	An exponent of the switching function.
n	An exponent of the switching function.

Construct a GaussianPK.

Definition at line 139 of file PairwiseKernel.h.

                                                             : 
        d0_(d0), r0_(r0), n_(n), m_(m) {}

Referenced by Build().

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Member Function Documentation

Build()

RationalSwitchPK * SSAGES::RationalSwitchPK::Build ( const Json::Value &  json, const std::string &  path  )

static

Build RationalSwitchPK from JSON value.

Parameters

json	JSON value node.
path	Path for JSON path specification.

Returns

Pointer to new RationalSwitchPK.

Parameters

json	JSON value node.

Returns

Pointer to new RationalSwitchPK.

Definition at line 77 of file PairwiseKernel.cpp.

    {
        Json::ObjectRequirement validator;
        Json::Value schema;
        Json::CharReaderBuilder rbuilder;
        Json::CharReader* reader = rbuilder.newCharReader();
 
        reader->parse(JsonSchema::RationalSwitchPK.c_str(),
                      JsonSchema::RationalSwitchPK.c_str() + JsonSchema::RationalSwitchPK.size(),
                      &schema, nullptr);
        validator.Parse(schema, path);
 
        // Validate inputs.
        validator.Validate(json, path);
        if(validator.HasErrors())
            throw BuildException(validator.GetErrors());
        return new RationalSwitchPK(
                    json["d0"].asDouble(), 
                    json["r0"].asDouble(), 
                    json["n"].asInt(), 
                    json["m"].asInt()
                );
    }

References Json::Requirement::GetErrors(), Json::Requirement::HasErrors(), Json::ObjectRequirement::Parse(), RationalSwitchPK(), and Json::ObjectRequirement::Validate().

Referenced by SSAGES::PairwiseKernel::Build().

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Evaluate()

double SSAGES::RationalSwitchPK::Evaluate ( double  rij, double &  df  ) const

inlineoverridevirtual

Evaluate the pairwise kernel function.

Parameters

rij	distance between two atoms.
df	Reference to variable which will store the gradient.

Returns

value of pairwise kernel function.

Implements SSAGES::PairwiseKernel.

Definition at line 142 of file PairwiseKernel.h.

        {
            const auto xarg = (rij - d0_)/r0_;
            const auto xn = std::pow(xarg, n_);
            const auto xm = std::pow(xarg, m_);
            const auto f = (1.-xn)/(1.-xm);
            
            df = f/(d0_-rij)*(n_*xn/(1.-xn)+m_*xm/(xm-1.));
            return  f;
        }

References d0_, m_, n_, and r0_.

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

• /home/michael/development/SSAGES/src/Utility/PairwiseKernel.h
• /home/michael/development/SSAGES/src/Utility/PairwiseKernel.cpp