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gmx::DensityFittingForce Class Reference

#include <gromacs/math/densityfittingforce.h>

Description

Manages evaluation of density-fitting forces for particles that were spread with a kernel.

The density fitting force is the inner product of the derivative of the density-density goodness-of-fit function at all density values and the gradient of the spreading kernel used to simulate the density.

For a discrete Gauss transform spreading kernel and density derivative $D$ it is the Gauss transform of a single coordinate, weighted by a distance vector and density derivative at each lattice point

\[ \sum_v D_v \frac{\vec{x_v} - \vec{x}}{\sigma^2} \frac{1}{\sigma^3 \sqrt(2^3*\pi^3)} * \exp(-\frac{(x_v-x)^2}{2 \sigma^2}) \]

Public Member Functions

 DensityFittingForce (const GaussianSpreadKernelParameters::Shape &kernelShapeParameters)
 Construct density fitting force evaluator. More...
 
 DensityFittingForce (const DensityFittingForce &other)
 Copy constructor.
 
DensityFittingForceoperator= (const DensityFittingForce &other)
 Copy assignment.
 
 DensityFittingForce (DensityFittingForce &&other) noexcept
 Move constructor.
 
DensityFittingForceoperator= (DensityFittingForce &&other) noexcept
 Move assignment.
 
RVec evaluateForce (const GaussianSpreadKernelParameters::PositionAndAmplitude &localParameters, basic_mdspan< const float, dynamicExtents3D > densityDerivative)
 Evaluate density-fitting force between a reference density and the density generated by a kernel. More...
 

Constructor & Destructor Documentation

gmx::DensityFittingForce::DensityFittingForce ( const GaussianSpreadKernelParameters::Shape kernelShapeParameters)

Construct density fitting force evaluator.

Parameters
[in]kernelShapeParametersthe global parameters of the density spreading kernel

Member Function Documentation

RVec gmx::DensityFittingForce::evaluateForce ( const GaussianSpreadKernelParameters::PositionAndAmplitude localParameters,
basic_mdspan< const float, dynamicExtents3D densityDerivative 
)

Evaluate density-fitting force between a reference density and the density generated by a kernel.

Implements the equation in the class description.

Parameters
[in]localParameterslocal parameters of the spreading kernel
[in]densityDerivativethe spatial derivative of the similarity measure between the reference density and a density that was generated using the spreading kernel
Returns
the force that increases the measure of the goodness of fit used to calculate the density derivative

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