net.esper.view.stat
Class UnivariateStatisticsView

java.lang.Object
  extended by net.esper.view.ViewSupport
      extended by net.esper.view.stat.UnivariateStatisticsView
All Implemented Interfaces:
Iterable<EventBean>, CloneableView, EventCollection, View, Viewable

public final class UnivariateStatisticsView
extends ViewSupport
implements CloneableView

View for computing statistics, which the view exposes via fields representing the sum, count, standard deviation for sample and for population and variance.


Field Summary
 
Fields inherited from class net.esper.view.ViewSupport
parent
 
Constructor Summary
UnivariateStatisticsView(StatementContext statementContext, String fieldName)
          Constructor requires the name of the field to use in the parent view to compute the statistics.
 
Method Summary
 View cloneView(StatementContext statementContext)
          Duplicates the view.
protected static EventType createEventType(StatementContext statementContext)
          Creates the event type for this view.
 EventType getEventType()
          Provides metadata information about the type of object the event collection contains.
 String getFieldName()
          Returns field name of the field to report statistics on.
 Iterator<EventBean> iterator()
          Allows iteration through all elements in this event collection.
 void setParent(Viewable parent)
          Called when the View is added to a Viewable object.
 String toString()
           
 void update(EventBean[] newData, EventBean[] oldData)
          Notify that data has been added or removed from the Viewable parent.
 
Methods inherited from class net.esper.view.ViewSupport
addView, dumpChildViews, dumpUpdateParams, findDescendent, getParent, getViews, hasViews, removeView, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

UnivariateStatisticsView

public UnivariateStatisticsView(StatementContext statementContext,
                                String fieldName)
Constructor requires the name of the field to use in the parent view to compute the statistics.

Parameters:
fieldName - is the name of the field within the parent view to use to get numeric data points for this view to compute the statistics on.
statementContext - contains required view services
Method Detail

cloneView

public View cloneView(StatementContext statementContext)
Description copied from interface: CloneableView
Duplicates the view.

Expected to return a same view in initialized state for grouping.

Specified by:
cloneView in interface CloneableView
Parameters:
statementContext - is services for the view
Returns:
duplicated view

setParent

public void setParent(Viewable parent)
Description copied from interface: View
Called when the View is added to a Viewable object.

Specified by:
setParent in interface View
Overrides:
setParent in class ViewSupport
Parameters:
parent - is the parent that this view is a child of

getFieldName

public final String getFieldName()
Returns field name of the field to report statistics on.

Returns:
field name

update

public final void update(EventBean[] newData,
                         EventBean[] oldData)
Description copied from interface: View
Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view. If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification. When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

Specified by:
update in interface View
Parameters:
newData - is the new data that has been added to the parent view
oldData - is the old data that has been removed from the parent view

getEventType

public final EventType getEventType()
Description copied from interface: EventCollection
Provides metadata information about the type of object the event collection contains.

Specified by:
getEventType in interface EventCollection
Returns:
metadata for the objects in the collection

iterator

public final Iterator<EventBean> iterator()
Description copied from interface: EventCollection
Allows iteration through all elements in this event collection. The iterator will return the elements in the collection in their natural order, or, if there is no natural ordering, in some unpredictable order.

Specified by:
iterator in interface Iterable<EventBean>
Specified by:
iterator in interface EventCollection
Returns:
an iterator which will go through all current elements in the collection.

toString

public final String toString()
Overrides:
toString in class Object

createEventType

protected static EventType createEventType(StatementContext statementContext)
Creates the event type for this view.

Parameters:
statementContext - is the event adapter service
Returns:
event type of view