Neighbours Class Reference

Calculate neighbour lists. More...

#include <neighbours.h>

Public Member Functions
	Neighbours (const std::vector< Atom > &atoms, float domainSideLength=-1.0)
	Construct a Neighbour list from some Atoms.
void	build (const std::vector< Atom > &atoms)
	Build the neighbour list from some Atoms.
void	clear ()
	Reset the spatial domains.
std::vector< std::pair< uint64_t, float > >	neighbours (const std::vector< Atom > &atoms, glm::vec3 position, float cutoff, bool noDirect=false, bool nearestImage=true) const
	Get the neighbours to a position within a cutoff using the spatial domains.
std::vector< std::pair< uint64_t, float > >	neighboursDirect (const std::vector< Atom > &atoms, glm::vec3 position, float cutoff, bool nearestImage=true) const
	Get the neighbours to a position within a cutoff by a direct evaluation.

Detailed Description

Calculate neighbour lists.

Remarks

spatial hashing based upon a fixed grid.

Constructor & Destructor Documentation

Neighbours()

Neighbours::Neighbours ( const std::vector< Atom > &  atoms, float  domainSideLength = -1.0  )

inline

Construct a Neighbour list from some Atoms.

Parameters

atoms

the Atoms to hash into spatial domains.

Member Function Documentation

build()

void Neighbours::build ( const std::vector< Atom > &  atoms )

inline

Build the neighbour list from some Atoms.

Parameters

atoms

the Atoms to hash into spatial domains.

clear()

void Neighbours::clear ( )

inline

Reset the spatial domains.

neighbours()

std::vector< std::pair< uint64_t, float > > Neighbours::neighbours ( const std::vector< Atom > &  atoms, glm::vec3  position, float  cutoff, bool  noDirect = false, bool  nearestImage = true  ) const

inline

Get the neighbours to a position within a cutoff using the spatial domains.

Parameters

atoms	the Atoms passed to Neighbours::build.
position	the position to find neighbours to.
cutoff	the spatial cutoff.
noDirect	force use of the spatial partitioning.
nearestImage	whether to use the nearest image convention.

Returns

std::vector<std::pair<uint64_t, float>> the indices of Atom neighbours to position and distances. In ascending distance order.

Remarks

The Atoms are passed as reference here and in Neighbours::build to avoid copying data. If different Atoms are passed in each distances will be wrong. If more Atoms are passed those with higher indices are ignored.

Atoms outside of bounds are ignored.

Unless noDirect is true. If the cutoff > the half-width of the spatial partitioning, a direct evaluation is performed.

Distance sorting ties are solved by atom index.

neighboursDirect()

std::vector< std::pair< uint64_t, float > > Neighbours::neighboursDirect ( const std::vector< Atom > &  atoms, glm::vec3  position, float  cutoff, bool  nearestImage = true  ) const

inline

Get the neighbours to a position within a cutoff by a direct evaluation.

Parameters

atoms	the Atoms passed to Neighbours::build.
position	the position to find neighbours to.
cutoff	the spatial cutoff.
nearestImage	whether to use the nearest image convention.

Returns

std::vector<std::pair<uint64_t, float>> the indices of Atom neighbours to position and distances. In ascending distance order.

Remarks

A direct O(atoms.size()) comparision is performed.

Distance sorting ties are solved by atom index.

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

• include/neighbours.h