infovis.metadata
Interface Aggregation

All Superinterfaces:

AggregationConstants, Constants

All Known Implementing Classes:

AdditiveAggregation, AtLeafAggregation, MinAggregation

public interface Aggregation
extends AggregationConstants

Interface Aggregation is used to check whether a column is aggregating following a specified rule in a tree. Aggregation can be additive, mean, min, max, etc.

Version:

$Revision: 1.4 $

Author:

Jean-Daniel Fekete

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

Method Summary

Column	aggregate(Column src, Tree tree, Column dst) Computes the aggregation values of the specified source column into the destination column.
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.

Method Detail

isAggregating

boolean isAggregating(Column col,
                      Tree tree)

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

Parameters:

col - the column

tree - the tree

Returns:

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

aggregate

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

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

Parameters:

src - the source column

tree - the tree

dst - the destination column

Returns:

the dst column.

getType

String getType()

Returns the type name of the aggregation.

Returns:

the type name of the aggregation.