Input_Output_Manager Class Reference

This class is responsible for the input, output and recode operations. More...

#include <Input_Output_Manager.hpp>

List of all members.

Public Member Functions
	Input_Output_Manager (ifstream &basket_file, const char *output_file_name)
int	read_in_a_line (vector< itemtype > &basket)
	Reads in one transaction from the basketfile.
unsigned long	find_frequent_items (const unsigned long min_supp, vector< unsigned long > &support_of_items)
	Determines the frequent items, fills in the new_code an new_code_inverse vectors.
void	basket_recode (const vector< itemtype > &original_basket, vector< itemtype > &new_basket)
	Creates an other basket that contains only the frequent items recoded.
void	write_out_basket (const set< itemtype > &itemset)
	Writes out an itemset to the output file.
void	write_out_basket_and_counter (const set< itemtype > &itemset, const unsigned long counter)
	Writes out an itemset and its counter to the output file.
void	rewind ()
	~Input_Output_Manager ()
Private Attributes
ifstream &	basket_file
	The file that contain the transactions (i.e baskets).
vector< itemtype >	new_code
	The new codes of the frequent items.
vector< itemtype >	new_code_inverse
	The inverse of new_code vector.

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Detailed Description

This class is responsible for the input, output and recode operations.

In frequent itemset mining (FIM) algorithms only frequent items are of interest. Hence it is useful to represent frequent items with integers: 1, 2, ..., n, where n is the number of frequent items. In the original transactional database, the items are also represented with integers, so we have to assign new integers to the frequent items.

Definition at line 34 of file Input_Output_Manager.hpp.

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Constructor & Destructor Documentation

Input_Output_Manager::Input_Output_Manager (  ifstream &  basket_file, const char *  output_file_name )

Author: Ferenc Bodon Definition at line 16 of file Input_Output_Manager.cpp.

Input_Output_Manager::~Input_Output_Manager (   )

Definition at line 156 of file Input_Output_Manager.cpp.

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Member Function Documentation

void Input_Output_Manager::basket_recode (  const vector< itemtype > &  original_basket, vector< itemtype > &  new_basket )

Creates an other basket that contains only the frequent items recoded. Parameters: original_basket  The basket to filter and recode. new_basket  The created reduced basket Definition at line 116 of file Input_Output_Manager.cpp. References new_code. Referenced by Apriori::support().

unsigned long Input_Output_Manager::find_frequent_items (  const unsigned long  min_supp, vector< unsigned long > &  support_of_items )

Determines the frequent items, fills in the new_code an new_code_inverse vectors. Parameters: min_supp  The (relative) support threshold. support_of_items  The support of the items. The ith least frequent item's support is given by support_of_items[i]. Returns: The number of transactions that the basketfile contains. Determining the support of the items Finding the frequent items Definition at line 58 of file Input_Output_Manager.cpp. References itemtype, new_code, new_code_inverse, and read_in_a_line(). Referenced by Apriori::APRIORI_alg().

int Input_Output_Manager::read_in_a_line (  vector< itemtype > &  basket  )

Reads in one transaction from the basketfile. Parameters: basket  The basket that will be filled with the next row of the file. Returns: 0 if the end of file is reached, otherwise 1; Definition at line 26 of file Input_Output_Manager.cpp. References basket_file, and itemtype. Referenced by find_frequent_items(), and Apriori::support().

void Input_Output_Manager::rewind (   )

Definition at line 150 of file Input_Output_Manager.cpp. References basket_file. Referenced by Apriori::APRIORI_alg().

void Input_Output_Manager::write_out_basket (  const set< itemtype > &  itemset  )

Writes out an itemset to the output file. Definition at line 126 of file Input_Output_Manager.cpp. References new_code_inverse.

void Input_Output_Manager::write_out_basket_and_counter (  const set< itemtype > &  itemset, const unsigned long  counter )

Writes out an itemset and its counter to the output file. Definition at line 136 of file Input_Output_Manager.cpp. References new_code_inverse. Referenced by Apriori::APRIORI_alg(), and Apriori_Trie::candidate_generation_assist().

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Member Data Documentation

ifstream& Input_Output_Manager::basket_file [private]

The file that contain the transactions (i.e baskets). Definition at line 67 of file Input_Output_Manager.hpp. Referenced by read_in_a_line(), and rewind().

vector<itemtype> Input_Output_Manager::new_code [private]

The new codes of the frequent items. if new_code[i] is 0, then i is not frequent, otherwise the new code of item i is new_code[i]-1. Definition at line 74 of file Input_Output_Manager.hpp. Referenced by basket_recode(), and find_frequent_items().

vector<itemtype> Input_Output_Manager::new_code_inverse [private]

The inverse of new_code vector. new_code_inverse[new_code[i]-1]=i if i is a frequent item. Definition at line 80 of file Input_Output_Manager.hpp. Referenced by find_frequent_items(), write_out_basket(), and write_out_basket_and_counter().

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

• Input_Output_Manager.hpp
• Input_Output_Manager.cpp

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