moost::algorithm Namespace Reference

Classes
struct	FastHashFunctor
	functor that uses fast_hash More...
class	ketama_partitioner
	ketama_partitioner implements consistent hashing, such that the addition or removal of buckets does not significantly change the mapping of keys to buckets. By using consistent hashing, only K/n keys need to be remapped on average, where K is the number of keys, and n is the number of buckets. More...
class	modulo_partitioner
	modulo_partitioner hashes the key then modulos the result against the number of buckets. This results in an even spread given a reasonable hasher. More...
class	partitioner
	A partitioner can assign templatized types to a specified number of buckets. More...
struct	SimpleAccumulatorPolicy
class	spline_interpolation
	Generate a spline interpolation of X and Y data points using the GNU Scientific Library. More...
struct	variable_length_encoding
Typedefs
typedef FastHashFunctor	FastHash
Functions
size_t	fast_hash (const void *data_in, size_t size, size_t seed=DEFAULT_SEED)
	free hash function
template<class ForwardIterator , class InputIterator >
ForwardIterator	inplace_set_intersection (ForwardIterator first1, ForwardIterator last1, InputIterator first2, InputIterator last2)
template<class ForwardIterator , class InputIterator , class StrictWeakOrdering >
ForwardIterator	inplace_set_intersection (ForwardIterator first1, ForwardIterator last1, InputIterator first2, InputIterator last2, StrictWeakOrdering comp)
template<typename FloatType , class ForwardIteratorX , class WeightAccessPolicyX , class ForwardIteratorY , class WeightAccessPolicyY , class AccumulatorPolicy >
FloatType	cosine_similarity (ForwardIteratorX x_beg, ForwardIteratorX x_end, WeightAccessPolicyX x_weight, ForwardIteratorY y_beg, ForwardIteratorY y_end, WeightAccessPolicyY y_weight, AccumulatorPolicy &accu)
template<typename FloatType , class ForwardIteratorX , class WeightAccessPolicyX , class ForwardIteratorY , class WeightAccessPolicyY >
FloatType	cosine_similarity (ForwardIteratorX x_beg, ForwardIteratorX x_end, WeightAccessPolicyX x_weight, ForwardIteratorY y_beg, ForwardIteratorY y_end, WeightAccessPolicyY y_weight)
Variables
static const size_t	DEFAULT_SEED = 5381

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Typedef Documentation

typedef FastHashFunctor moost::algorithm::FastHash

Definition at line 143 of file fast_hash.hpp.

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Function Documentation

template<typename FloatType , class ForwardIteratorX , class WeightAccessPolicyX , class ForwardIteratorY , class WeightAccessPolicyY , class AccumulatorPolicy >

FloatType moost::algorithm::cosine_similarity	(	ForwardIteratorX	x_beg,
		ForwardIteratorX	x_end,
		WeightAccessPolicyX	x_weight,
		ForwardIteratorY	y_beg,
		ForwardIteratorY	y_end,
		WeightAccessPolicyY	y_weight,
		AccumulatorPolicy &	accu
	)

Cosine similarity algorithm

This function template implements a generic cosine similarity algorithm for two arbitrary dimension feature vectors X and Y.

Note that this implementation requires both input vectors to be sorted and that dimensions of both vectors must be less-than comparable.

Template Parameters:

FloatType	Floating point type used for internal computation and return value.
ForwardIteratorX	Iterator type of vector X.
WeightAccessPolicyX	Policy for accessing the weight of a dimension in X.
ForwardIteratorY	Iterator type of vector Y.
WeightAccessPolicyY	Policy for accessing the weight of a dimension in Y.
AccumulatorPolicy	Policy for summing the feature matches (dot product parts). Defaults to SimpleAccumulatorPolicy<FloatType>, but a different policy could be used e.g. for counting the number of matches.

Parameters:

x_beg	Iterator to the start of vector X.
x_end	Iterator to the end of vector X.
x_weight	Policy to access the weight of a dimension in vector X.
y_beg	Iterator to the start of vector Y.
y_end	Iterator to the end of vector Y.
y_weight	Policy to access the weight of a dimension in vector Y.
accu	Accumulator policy.

Definition at line 83 of file similarity.hpp.

template<typename FloatType , class ForwardIteratorX , class WeightAccessPolicyX , class ForwardIteratorY , class WeightAccessPolicyY >

FloatType moost::algorithm::cosine_similarity	(	ForwardIteratorX	x_beg,
		ForwardIteratorX	x_end,
		WeightAccessPolicyX	x_weight,
		ForwardIteratorY	y_beg,
		ForwardIteratorY	y_end,
		WeightAccessPolicyY	y_weight
	)

Definition at line 143 of file similarity.hpp.

size_t moost::algorithm::fast_hash	(	const void *	data_in,
		size_t	size,
		size_t	seed = DEFAULT_SEED
	)		[inline]

free hash function

Definition at line 92 of file fast_hash.hpp.

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template<class ForwardIterator , class InputIterator >

ForwardIterator moost::algorithm::inplace_set_intersection	(	ForwardIterator	first1,
		ForwardIterator	last1,
		InputIterator	first2,
		InputIterator	last2
	)

Definition at line 42 of file inplace_set_intersection.hpp.

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template<class ForwardIterator , class InputIterator , class StrictWeakOrdering >

ForwardIterator moost::algorithm::inplace_set_intersection	(	ForwardIterator	first1,
		ForwardIterator	last1,
		InputIterator	first2,
		InputIterator	last2,
		StrictWeakOrdering	comp
	)

Definition at line 65 of file inplace_set_intersection.hpp.

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Variable Documentation

const size_t moost::algorithm::DEFAULT_SEED = 5381 [static]

Definition at line 87 of file fast_hash.hpp.