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.


Copyright 2005 by Jean-Daniel Fekete and INRIA, France All rights reserved.