#include <toolkits/pattern_mining/fp_results_tree.hpp>

Public Member Functions
void	save (oarchive &oarc) const

void	load (iarchive &iarc)

void	add_itemset (const std::vector< size_t > &potential_itemset, const size_t &support)

size_t	get_min_support_bound ()

void	insert_support (const size_t &support)

gl_sframe	get_closed_itemsets (const std::shared_ptr< topk_indexer > &indexer=nullptr) const

bool	is_itemset_redundant (const std::vector< size_t > &potential_itemset, const size_t &support) const

void	build_tree (const gl_sframe &closed_itemsets)

std::vector< dense_bitset >	get_top_k_closed_bitsets (const size_t &size, const size_t &top_k=TOP_K_MAX, const size_t &min_length=1) const

gl_sframe	get_top_k_closed_itemsets (const size_t &top_k=TOP_K_MAX, const size_t &min_length=1, const std::shared_ptr< topk_indexer > &indexer=nullptr) const

std::vector< size_t >	sort_itemset (const std::vector< size_t > &itemset) const

size_t	get_support (const std::vector< size_t > &sorted_itemset, const size_t &lower_bound_on_support=0) const

size_t	get_num_transactions () const

void	prune_tree (const size_t &min_support)

Detailed Description

Tree data structure for keeping track of the top_k frequent 'closed' itemsets of length at least min_length This is a compressed, memory efficient data structure used to store and during the mining of 'closed' itemsets.

Extends the fp_results_tree class Additional Vars: top_k (size_t) - maximum number of closed itemsets to mine top_k should be less than TOP_K_MAX min_length (size_t) - minimum length of a closed itemset min_support_heap (min_heap) - min heap of top_k supports

Definition at line 244 of file fp_results_tree.hpp.

Member Function Documentation

◆ add_itemset()

void turi::pattern_mining::fp_top_k_results_tree::add_itemset	(	const std::vector< size_t > &	potential_itemset,
		const size_t &	support
	)

virtual

Add a potential closed itemset to the tree

Args: potential_itemset (vector of size_ts) - itemset to add support (size_t) - support of the itemset

Reimplemented from turi::pattern_mining::fp_results_tree.

◆ build_tree()

void turi::pattern_mining::fp_results_tree::build_tree ( const gl_sframe & closed_itemsets )

inherited

Build results tree from a collection of closed itemsets

Args: closed_itemsets (gl_sframe) - sframe of closed itemset (ids), support

◆ get_closed_itemsets()

gl_sframe turi::pattern_mining::fp_top_k_results_tree::get_closed_itemsets ( const std::shared_ptr< topk_indexer > & indexer = nullptr ) const

Overrides fp_result_tree::get_closed_itemsets Return the current collection of closed itemsets Args: indexer: An indexer to convert from id to the value.

Returns: closed_itemsets (gl_sframe) - sframe of closed itemset (ids), support

◆ get_min_support_bound()

size_t turi::pattern_mining::fp_top_k_results_tree::get_min_support_bound ( )

Get a bound for the min_support.

Returns: A current estimate of min support.

◆ get_num_transactions()

size_t turi::pattern_mining::fp_results_tree::get_num_transactions ( ) const

inlineinherited

Get the number of transaction

Definition at line 191 of file fp_results_tree.hpp.

◆ get_support()

size_t turi::pattern_mining::fp_results_tree::get_support	(	const std::vector< size_t > &	sorted_itemset,
		const size_t &	lower_bound_on_support = `0`
	)		const

inherited

Get the support for a frequent itemset Note: the support for the empty set is the total number of transactions

Args: sorted_itemset (vector of size_t) - a sorted frequent itemset (not necessarily closed) (see sort_itemset). lower_bound_on_support (size_t) - optional, for efficiency Returns: support (size_t)

◆ get_top_k_closed_bitsets()

std::vector<dense_bitset> turi::pattern_mining::fp_results_tree::get_top_k_closed_bitsets	(	const size_t &	size,
		const size_t &	top_k = `TOP_K_MAX`,
		const size_t &	min_length = `1`
	)		const

inherited

Return the current collection of closed itemsets as bitsets.

Args: size: Size of each bitset returned. top_k (size_t) - maximum number of closed itemsets to returns min_length (size_t) - minimum required length for a closed itemset

Returns: closed_bitsets - Vector of bitsets representing each set.

◆ get_top_k_closed_itemsets()

gl_sframe turi::pattern_mining::fp_results_tree::get_top_k_closed_itemsets	(	const size_t &	top_k = `TOP_K_MAX`,
		const size_t &	min_length = `1`,
		const std::shared_ptr< topk_indexer > &	indexer = `nullptr`
	)		const

inherited

Return the top_k closed itemsets in descending order.

Takes longer than get_closed_itemsets() due to sorting, but is faster than trying to sort a gl_sframe.

Args: top_k (size_t) - maximum number of closed itemsets to returns min_length (size_t) - minimum required length for a closed itemset

Returns: top_k_closed_itemsets (gl_sframe) - sframe of top_k itemsets, support

◆ insert_support()

void turi::pattern_mining::fp_top_k_results_tree::insert_support ( const size_t & support )

Insert support into the min_support heap.

Args: support (size_t) - support of the itemset

◆ is_itemset_redundant()

bool turi::pattern_mining::fp_results_tree::is_itemset_redundant	(	const std::vector< size_t > &	potential_itemset,
		const size_t &	support
	)		const

inherited

Check if frequent itemset cannot be closed

Checks if the itemset is a subset of an existing itemset in the tree with equal support. Returns true if a subset with equal support exists.

Args: potential_itemset (vector of size_t) - itemset to check Returns: is_redundant (bool) - whether the itemset passes the test

◆ load()

void turi::pattern_mining::fp_top_k_results_tree::load ( iarchive & iarc )

inline

Load the fp_results_tree from an iarc.

Definition at line 276 of file fp_results_tree.hpp.

◆ prune_tree()

void turi::pattern_mining::fp_results_tree::prune_tree ( const size_t & min_support )

inherited

Prune Tree Pass over the tree, removing all nodes (corresponding to itemsets) with support strictly less than the given (final) min support Rebuilds tree -> Should be rarely called (ideally only at the end)

Args: min_support (size_t)

◆ save()

void turi::pattern_mining::fp_top_k_results_tree::save ( oarchive & oarc ) const

inline

Save the fp_results_tree into a oarc.

Definition at line 259 of file fp_results_tree.hpp.

◆ sort_itemset()

std::vector<size_t> turi::pattern_mining::fp_results_tree::sort_itemset ( const std::vector< size_t > & itemset ) const

inherited

Sort itemset by id_order_map (last element first) Args: itemset (vector of size_ts) Returns: sorted_itemset (vector of size_ts)

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

toolkits/pattern_mining/fp_results_tree.hpp

Public Member Functions

Detailed Description

Member Function Documentation

◆ add_itemset()

◆ build_tree()

◆ get_closed_itemsets()

◆ get_min_support_bound()

◆ get_num_transactions()

◆ get_support()

◆ get_top_k_closed_bitsets()

◆ get_top_k_closed_itemsets()

◆ insert_support()

◆ is_itemset_redundant()

◆ load()

◆ prune_tree()

◆ save()

◆ sort_itemset()