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This page gives some advice to create a new Aggregation function.

This page is under construction.


Interfaces for a new function

An aggregation function needs to implement one of the following interfaces:

  • de.uniol.inf.is.odysseus.aggregation.functions.IIncrementalAggregationFunction
    An incremental aggregation functions gets a notification when an element gets valid (enters the window) or gets invalid (leaves the window). You have to hold a state to return the current aggregation value on request. 
    • void addNew(T newElement);
      This function is called when a new element gets valid. You should add this value to the state.
      For example AVG function: State holds sum and count. sum += newElement and count++ 
  • de.uniol.inf.is.odysseus.aggregation.functions.INonIncrementalAggregationFunction

 

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