Interface StructureProducer

All Known Implementing Classes:
Associator, ClassAssigner, ClassValuePicker, CrossValidationFoldMaker, FlowByExpression, Join, Loader, Sorter, TestSetMaker, TrainingSetMaker, TrainTestSplitMaker

public interface StructureProducer
Interface for something that can describe the structure of what is encapsulated in a named event type as an empty set of Instances (i.e. attribute information only). For example, batchAssociationRulesEvent can be described as LHS (String), RHS (String) and a number of metrics (Numeric); dataSetEvent, instanceEvent, trainingSetEvent etc. are all straightforward, since they already encapsulate instances; textEvent can be described in terms of the title (String) and the body (String) of the text. Sometimes it is not possible to know the structure of the encapsulated output in advance (e.g. certain filters may not know how many attributes will be produced until the input data arrives), in this case any implementing class can return null to indicate this.
Version:
$Revision: 8034 $
Author:
Mark Hall (mhall{[at]}pentaho{[dot]}com)
  • Method Summary

    Modifier and Type
    Method
    Description
    getStructure(String eventName)
    Get the structure of the output encapsulated in the named event.
  • Method Details

    • getStructure

      Instances getStructure(String eventName)
      Get the structure of the output encapsulated in the named event. If the structure can't be determined in advance of seeing input, or this StructureProducer does not generate the named event, null should be returned.
      Parameters:
      eventName - the name of the output event that encapsulates the requested output.
      Returns:
      the structure of the output encapsulated in the named event or null if it can't be determined in advance of seeing input or the named event is not generated by this StructureProduce.