lshkit::Repeat< LSH > Class Template Reference

Concatenation of a number of LSHes. More...

#include <composite.h>

List of all members.

Public Types
typedef LSH	Super
typedef Super::Domain	Domain
Public Member Functions
template<typename RNG>
void	reset (const Parameter &param, RNG &rng)
template<typename RNG>
	Repeat (const Parameter &param, RNG &rng)
unsigned	getRange () const
unsigned	operator() (Domain obj) const
template<class Archive>
void	serialize (Archive &ar, const unsigned int version)
Protected Attributes
std::vector< Super >	lsh_
unsigned	dup_
unsigned	range_
unsigned	unit_
Classes
struct	Parameter

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Detailed Description

template<typename LSH>
class lshkit::Repeat< LSH >

Concatenation of a number of LSHes.

The concatenation of a number of LSHes of the same class is usually used as a new LSH to augment the locality sensitivity. The Repeat class is to concatenate N independent LSH instances.

The domain of LSH remains the same. The new parameter is defined as:

      struct Parameter {
          unsigned repeat;     // # of LSHes to concatenate.
          ...                  // all parameters of the base LSH are inherited.
      };

Because the hash value is represented as unsigned int, which has only 32 bits, the range of the original LSH need to be small enough so that the concatenated value does not overflow. Specifically, we require that

We also require that the range of the base LSH only depends on the parameter, so an array of such LSHes initialized with the same parameter but independent random numbers have the same range.

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

• include/lshkit/composite.h

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