#include <IndexLSH.h>

Inheritance diagram for faiss::IndexLSH:

Public Types
typedef unsigned char	uint8_t

Public Types inherited from faiss::Index
typedef long	idx_t
	all indices are this type

Public Member Functions
	IndexLSH (idx_t d, int nbits, bool rotate_data=true, bool train_thresholds=false)

const float *	apply_preprocess (idx_t n, const float *x) const

void	train (idx_t n, const float *x) override

void	add (idx_t n, const float *x) override

void	search (idx_t n, const float x, idx_t k, float distances, idx_t *labels) const override

void	reset () override
	removes all elements from the database.

void	transfer_thresholds (LinearTransform *vt)

Public Member Functions inherited from faiss::Index
	Index (idx_t d=0, MetricType metric=METRIC_INNER_PRODUCT)

virtual void	add_with_ids (idx_t n, const float x, const long xids)

virtual void	range_search (idx_t n, const float x, float radius, RangeSearchResult result) const

void	assign (idx_t n, const float x, idx_t labels, idx_t k=1)

virtual long	remove_ids (const IDSelector &sel)

virtual void	reconstruct (idx_t key, float *recons) const

virtual void	reconstruct_n (idx_t i0, idx_t ni, float *recons) const

void	compute_residual (const float x, float residual, idx_t key) const

void	display () const

Public Attributes
int	nbits
	nb of bits per vector

int	bytes_per_vec
	nb of 8-bits per encoded vector

bool	rotate_data
	whether to apply a random rotation to input

bool	train_thresholds
	whether we train thresholds or use 0

RandomRotationMatrix	rrot
	optional random rotation

std::vector< float >	thresholds
	thresholds to compare with

std::vector< uint8_t >	codes
	encoded dataset

Public Attributes inherited from faiss::Index
int	d
	vector dimension

idx_t	ntotal
	total nb of indexed vectors

bool	verbose
	verbosity level

bool	is_trained
	set if the Index does not require training, or if training is done already

MetricType	metric_type
	type of metric this index uses for search

Detailed Description

The sign of each vector component is put in a binary signature

Definition at line 24 of file IndexLSH.h.

Member Function Documentation

void faiss::IndexLSH::add	(	idx_t	n,
		const float *	x
	)

overridevirtual

Add n vectors of dimension d to the index.

Vectors are implicitly assigned labels ntotal .. ntotal + n - 1 This function slices the input vectors in chuncks smaller than blocksize_add and calls add_core.

Parameters

x	input matrix, size n * d

Implements faiss::Index.

Definition at line 116 of file IndexLSH.cpp.

const float * faiss::IndexLSH::apply_preprocess	(	idx_t	n,
		const float *	x
	)		const

Preprocesses and resizes the input to the size required to binarize the data

Parameters

x	input vectors, size n * d

Returns: output vectors, size n * bits. May be the same pointer as x, otherwise it should be deleted by the caller

Definition at line 50 of file IndexLSH.cpp.

void faiss::IndexLSH::search	(	idx_t	n,
		const float *	x,
		idx_t	k,
		float *	distances,
		idx_t *	labels
	)		const

overridevirtual

query n vectors of dimension d to the index.

return at most k vectors. If there are not enough results for a query, the result array is padded with -1s.

Parameters

x	input vectors to search, size n * d
labels	output labels of the NNs, size n*k
distances	output pairwise distances, size n*k

Implements faiss::Index.

Definition at line 128 of file IndexLSH.cpp.

void faiss::IndexLSH::train	(	idx_t	,
		const float *
	)

overridevirtual

Perform training on a representative set of vectors

Parameters

n	nb of training vectors
x	training vecors, size n * d

Reimplemented from faiss::Index.

Definition at line 85 of file IndexLSH.cpp.

void faiss::IndexLSH::transfer_thresholds ( LinearTransform * vt )

transfer the thresholds to a pre-processing stage (and unset train_thresholds)

Definition at line 160 of file IndexLSH.cpp.

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

/data/users/matthijs/github_faiss/faiss/IndexLSH.h
/data/users/matthijs/github_faiss/faiss/IndexLSH.cpp

Public Types

Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation