edu.mssm.crover.tables.treatments
Class Aggregation

java.lang.Object
  edu.mssm.crover.tables.treatments.Aggregation

public class Aggregation
extends Object

Aggregation operation on tables, similar to Mineset aggregation. Just a little bit more flexible about the aggregation operations (Mineset proposes: Sum, Average, Count, Min, Max); This class supports any operation that accept a set of instances from the source table and computes an object or a primitive type.

Nested Class Summary

protected class

Aggregation.Aggregate

Field Summary

protected Object

parameter

Constructor Summary

Aggregation()

Aggregation(Object parameter)
Variant useful for customization.

Method Summary

void	aggregate(String columnIdentifier)
Table	aggregate(Table source) Performs the aggregation operation on source, returns the new table.
protected void	begin(Table source, Table dest) Override to add the aggregation columns to the destination table.
void	doNotAggregate(String columnIdentifier)
void	doNotGroupBy(String columnIdentifier)
void	doNotRemove(String columnIdentifier)
protected void	end(Table source, Table dest) Invoked after every row has been processed.
Object	getParameter() Returns the parameter passed at construction time.
void	groupBy(String columnIdentifier)
boolean	isAggregateColumn(String columnIdentifier)
boolean	isGroupByColumn(String columnIdentifier)
protected boolean	isInGroup(String element, String[] group)
boolean	isRemoveColumn(String columnIdentifier)
static void	main(String[] args) Example and test of use for this class.
void	remove(String columnIdentifier)
protected void	treatAggregate(Table source, Table.RowIterator[] aggregate, Table dest) Called for each aggregat of the source table.
void	treatInstance(Table dest, Table.RowIterator ri)
protected int	whereInGroup(String element, String[] group) Returns the index of the element in the group.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

parameter

protected Object parameter

Constructor Detail

Aggregation

public Aggregation(Object parameter)

Variant useful for customization. Pass whatever parameter you will need during the aggregation, and retrieve it latter through getParameter()

See Also:

getParameter()

Aggregation

public Aggregation()

Method Detail

getParameter

public Object getParameter()

Returns the parameter passed at construction time.

groupBy

public void groupBy(String columnIdentifier)

doNotGroupBy

public void doNotGroupBy(String columnIdentifier)

isGroupByColumn

public boolean isGroupByColumn(String columnIdentifier)

isRemoveColumn

public boolean isRemoveColumn(String columnIdentifier)

isAggregateColumn

public boolean isAggregateColumn(String columnIdentifier)

isInGroup

protected boolean isInGroup(String element,
                            String[] group)

remove

public void remove(String columnIdentifier)

doNotRemove

public void doNotRemove(String columnIdentifier)

aggregate

public void aggregate(String columnIdentifier)

doNotAggregate

public void doNotAggregate(String columnIdentifier)

whereInGroup

protected int whereInGroup(String element,
                           String[] group)

Returns the index of the element in the group.

Returns:

-1 when the element is not part of the group.

aggregate

public Table aggregate(Table source)
                throws TreatmentInterrupted

Performs the aggregation operation on source, returns the new table. When no groupBy table is specified, the aggregation typically creates only one aggregate that contains all the instances of the source table.

Throws:

TreatmentInterrupted

treatInstance

public void treatInstance(Table dest,
                          Table.RowIterator ri)

begin

protected void begin(Table source,
                     Table dest)
              throws Exception

Override to add the aggregation columns to the destination table. Invoked before any row has had a chance to be processed.

Throws:

Exception

end

protected void end(Table source,
                   Table dest)

Invoked after every row has been processed.

treatAggregate

protected void treatAggregate(Table source,
                              Table.RowIterator[] aggregate,
                              Table dest)
                       throws Exception

Called for each aggregat of the source table. An aggregat is the set of row iterators of the source table that have the same values of the n-uplet (c1, ... cn), ci being a column of the source table. An aggregation can be seen as a projection, from the space of the complete source table columns to the space of the aggregated columns.

Throws:

Exception

main

public static void main(String[] args)

Example and test of use for this class. TODO: Convert to junit test