Public Types
enum	QuantizerType { QT_8bit, QT_4bit, QT_8bit_uniform, QT_4bit_uniform }

enum	RangeStat { RS_minmax, RS_meanstd, RS_quantiles, RS_optim }

Public Member Functions
	ScalarQuantizer (size_t d, QuantizerType qtype)

void	train (size_t n, const float *x)

void	compute_codes (const float x, uint8_t codes, size_t n) const
	same as compute_code for several vectors

void	decode (const uint8_t code, float x, size_t n) const
	decode a vector from a given code (or n vectors if third argument)

DistanceComputer *	get_distance_computer (MetricType metric=METRIC_L2) const

Public Attributes
QuantizerType	qtype

RangeStat	rangestat

float	rangestat_arg

size_t	d
	dimension of input vectors

size_t	code_size
	bytes per vector

std::vector< float >	trained
	trained values (including the range)

Detailed Description

The uniform quantizer has a range [vmin, vmax]. The range can be the same for all dimensions (uniform) or specific per dimension (default).

Definition at line 30 of file IndexScalarQuantizer.h.

Member Enumeration Documentation

Enumerator
QT_8bit	8 bits per component
QT_4bit	4 bits per component
QT_8bit_uniform	same, shared range for all dimensions

Definition at line 32 of file IndexScalarQuantizer.h.

The uniform encoder can estimate the range of representable values of the unform encoder using different statistics. Here rs = rangestat_arg

Enumerator
RS_minmax	[min - rs(max-min), max + rs(max-min)]
RS_meanstd	[mean - std * rs, mean + std * rs]
RS_quantiles	[Q(rs), Q(1-rs)]
RS_optim	alternate optimization of reconstruction error

Definition at line 46 of file IndexScalarQuantizer.h.

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