87 lines
3.0 KiB
C++
87 lines
3.0 KiB
C++
/*
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----
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This file is part of SECONDO.
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Copyright (C) 2021, University in Hagen, Department of Computer Science,
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Database Systems for New Applications.
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SECONDO is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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SECONDO is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with SECONDO; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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----
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//paragraph [1] Title: [{\Large \bf \begin {center}] [\end {center}}]
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[1] Association Analysis Algebra Implementation
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January 2021 - April 2021, P. Fedorow for bachelor thesis.
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*/
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#pragma once
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#include "Algebras/Collection/IntSet.h"
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#include "Algebras/Relation-C++/RelationAlgebra.h" // rel, trel, tuple
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#include "NestedList.h"
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#include "Operator.h"
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#include <utility>
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#include <vector>
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namespace AssociationAnalysis {
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// Local info class for the eclat operator. Contains the implementation of the
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// eclat-algorithm.
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class eclatLI {
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public:
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// Finds all frequent itemsets that satisfy the support given by minSupport.
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// The itemset of a transaction is extracted from each tuple of the relation
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// by an index given by itemsetAttr.
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eclatLI(GenericRelation *relation, int minSupport, int itemsetAttr,
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int deoptimize);
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~eclatLI() { this->tupleType->DeleteIfAllowed(); }
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// Returns the next frequent itemset as a tuple.
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Tuple *getNext();
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private:
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// Used to generate a stream of the frequent itemsets.
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std::vector<std::pair<std::vector<int>, double>>::const_iterator it;
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// Contains the frequent itemsets annotated by their support.
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std::vector<std::pair<std::vector<int>, double>> frequentItemsets;
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// Describes the resulting tuple type: tuple(Itemset: intset, Support: real).
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TupleType *tupleType;
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};
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// Operator info for the eclat operator.
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struct eclatInfo : OperatorInfo {
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eclatInfo() : OperatorInfo() {
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this->name = "eclat";
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this->signature = "rel(tuple(...)) attr real -> stream(tuple(Itemset: "
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"intset, Support: real))";
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this->appendSignature("rel(tuple(...)) attr int -> stream(tuple(Itemset: "
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"intset, Support: real))");
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this->syntax = "_ eclat[_, _]";
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this->meaning = "Discovers the frequent itemsets in the given relation of "
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"transactions by using the eclat-algorithm. The expected "
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"arguments are: the relation that contains the "
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"transactions, the name of the attribute that contains the "
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"items as an intset and the minimum support to look for.";
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this->usesArgsInTypeMapping = true;
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}
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};
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} // namespace AssociationAnalysis
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