infovis.metadata
Class AtLeafAggregation

java.lang.Object
  infovis.metadata.AtLeafAggregation

All Implemented Interfaces:

Aggregation, AggregationConstants, Constants

public class AtLeafAggregation
extends Object
implements Aggregation

A Column in a Tree is considerer aggregated at the leaf level it only its leave nodes have defined values. Such columns can the be used using most aggregation types (additive, min, max, etc.) by filling the inner nodes with the desired aggregation function without breaking the column's visible semantic.

Version:

$Revision: 1.7 $

Author:

Jean-Daniel Fekete

InfoVis factory arguments:

AggregationFactory AtLeaf

Field Summary

Fields inherited from interface infovis.metadata.AggregationConstants

AGGREGATE_COMPATIBLE, AGGREGATE_NO, AGGREGATE_YES, AGGREGATION_TYPE, AGGREGATION_TYPE_ADDITIVE, AGGREGATION_TYPE_ATLEAF, AGGREGATION_TYPE_CONCAT, AGGREGATION_TYPE_MAX, AGGREGATION_TYPE_MEAN, AGGREGATION_TYPE_MIN, AGGREGATION_TYPE_NONE

Fields inherited from interface infovis.metadata.Constants

CONTRIBUTOR, COVERAGE, CREATOR, DATE, DESCRITION, FORMAT, IDENTIFIER, LANGUAGE, PUBLISHER, RELATION, RIGHTS, SOURCE, SUBJECT, TITLE, TYPE

Constructor Summary

AtLeafAggregation()

Method Summary

Column	aggregate(Column src, Tree tree, Column dst) Computes the aggregation values of the specified source column into the destination column.
static AtLeafAggregation	getInstance()
String	getType() Returns the type name of the aggregation.
boolean	isAggregating(Column col, Tree tree) Checks whether a column is aggregating following the class aggregation scheme.
static boolean	isAtLeaf(Column col, Tree tree)

Methods inherited from class java.lang.Object

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

Constructor Detail

AtLeafAggregation

public AtLeafAggregation()

Method Detail

getInstance

public static AtLeafAggregation getInstance()

isAggregating

public boolean isAggregating(Column col,
                             Tree tree)

Description copied from interface: Aggregation

Checks whether a column is aggregating following the class aggregation scheme.

Specified by:

isAggregating in interface Aggregation

Parameters:

col - the column

tree - the tree

Returns:

true if the column follows the aggregation scheme, false otherwise.

aggregate

public Column aggregate(Column src,
                        Tree tree,
                        Column dst)

Description copied from interface: Aggregation

Computes the aggregation values of the specified source column into the destination column. Source and destination should be allocated and of the right type.

Specified by:

aggregate in interface Aggregation

Parameters:

src - the source column

tree - the tree

dst - the destination column

Returns:

the dst column.

getType

public String getType()

Description copied from interface: Aggregation

Returns the type name of the aggregation.

Specified by:

getType in interface Aggregation

Returns:

the type name of the aggregation.

isAtLeaf

public static final boolean isAtLeaf(Column col,
                                     Tree tree)