/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.view.stat;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.collection.SingleEventIterator;
import com.espertech.esper.core.context.util.AgentInstanceContext;
import com.espertech.esper.epl.expression.ExprEvaluator;
import com.espertech.esper.epl.expression.ExprNode;
import com.espertech.esper.event.EventAdapterService;
import com.espertech.esper.view.DerivedValueView;
import com.espertech.esper.view.ViewSupport;
import java.util.Iterator;
/**
* View for computing statistics that require 2 input variable arrays containing X and Y datapoints.
* Subclasses compute correlation or regression values, for instance.
*/
public abstract class BaseBivariateStatisticsView extends ViewSupport implements DerivedValueView
{
/**
* This bean can be overridden by subclasses providing extra values such as correlation, regression.
*/
protected BaseStatisticsBean statisticsBean = new BaseStatisticsBean();
private final ExprNode expressionX;
private final ExprNode expressionY;
private final ExprEvaluator expressionXEval;
private final ExprEvaluator expressionYEval;
private final EventBean[] eventsPerStream = new EventBean[1];
/**
* Services required by implementing classes.
*/
protected final AgentInstanceContext agentInstanceContext;
/**
* Additional properties.
*/
protected final StatViewAdditionalProps additionalProps;
/**
* Event type.
*/
protected final EventType eventType;
protected Object[] lastValuesEventNew;
private EventBean lastNewEvent;
/**
* Populate bean.
* @param baseStatisticsBean results
* @param eventAdapterService event adapters
* @param eventType type
* @param additionalProps additional props
* @param decoration decoration values
* @return bean
*/
protected abstract EventBean populateMap(BaseStatisticsBean baseStatisticsBean, EventAdapterService eventAdapterService,
EventType eventType, StatViewAdditionalProps additionalProps, Object[] decoration);
/**
* Constructor requires the name of the two fields to use in the parent view to compute the statistics.
* @param expressionX is the expression to get the X values from
* @param expressionY is the expression to get the Y values from
* @param agentInstanceContext contains required view services
* @param eventType type of event
* @param additionalProps additional props
*/
public BaseBivariateStatisticsView(AgentInstanceContext agentInstanceContext,
ExprNode expressionX,
ExprNode expressionY,
EventType eventType,
StatViewAdditionalProps additionalProps
)
{
this.agentInstanceContext = agentInstanceContext;
this.expressionX = expressionX;
this.expressionXEval = expressionX.getExprEvaluator();
this.expressionY = expressionY;
this.expressionYEval = expressionY.getExprEvaluator();
this.eventType = eventType;
this.additionalProps = additionalProps;
}
public void update(EventBean[] newData, EventBean[] oldData)
{
// If we have child views, keep a reference to the old values, so we can fireStatementStopped them as old data event.
EventBean oldValues = null;
if (lastNewEvent == null)
{
if (this.hasViews())
{
oldValues = populateMap(statisticsBean, agentInstanceContext.getStatementContext().getEventAdapterService(), eventType, additionalProps, lastValuesEventNew);
}
}
// add data points to the bean
if (newData != null)
{
for (int i = 0; i < newData.length; i++)
{
eventsPerStream[0] = newData[i];
Number xnum = (Number) expressionXEval.evaluate(eventsPerStream, true, agentInstanceContext);
Number ynum = (Number) expressionYEval.evaluate(eventsPerStream, true, agentInstanceContext);
if (xnum != null && ynum != null) {
double X = xnum.doubleValue();
double Y = ynum.doubleValue();
statisticsBean.addPoint(X, Y);
}
}
if ((additionalProps != null) && (newData.length != 0)) {
if (lastValuesEventNew == null) {
lastValuesEventNew = new Object[additionalProps.getAdditionalExpr().length];
}
for (int val = 0; val < additionalProps.getAdditionalExpr().length; val++) {
lastValuesEventNew[val] = additionalProps.getAdditionalExpr()[val].evaluate(eventsPerStream, true, agentInstanceContext);
}
}
}
// remove data points from the bean
if (oldData != null)
{
for (int i = 0; i < oldData.length; i++)
{
eventsPerStream[0] = oldData[i];
Number xnum = (Number) expressionXEval.evaluate(eventsPerStream, true, agentInstanceContext);
Number ynum = (Number) expressionYEval.evaluate(eventsPerStream, true, agentInstanceContext);
if (xnum != null && ynum != null) {
double X = xnum.doubleValue();
double Y = ynum.doubleValue();
statisticsBean.removePoint(X, Y);
}
}
}
// If there are child view, fireStatementStopped update method
if (this.hasViews())
{
EventBean newDataMap = populateMap(statisticsBean, agentInstanceContext.getStatementContext().getEventAdapterService(), eventType, additionalProps, lastValuesEventNew);
if (lastNewEvent == null)
{
updateChildren(new EventBean[] {newDataMap}, new EventBean[] {oldValues});
}
else
{
updateChildren(new EventBean[] {newDataMap}, new EventBean[] {lastNewEvent});
}
lastNewEvent = newDataMap;
}
}
public final Iterator<EventBean> iterator()
{
return new SingleEventIterator(populateMap(statisticsBean,
agentInstanceContext.getStatementContext().getEventAdapterService(),
eventType, additionalProps, lastValuesEventNew));
}
/**
* Returns the expression supplying X data points.
* @return X expression
*/
public final ExprNode getExpressionX()
{
return expressionX;
}
/**
* Returns the expression supplying Y data points.
* @return Y expression
*/
public final ExprNode getExpressionY()
{
return expressionY;
}
public BaseStatisticsBean getStatisticsBean() {
return statisticsBean;
}
public Object[] getLastValuesEventNew() {
return lastValuesEventNew;
}
public void setLastValuesEventNew(Object[] lastValuesEventNew) {
this.lastValuesEventNew = lastValuesEventNew;
}
public StatViewAdditionalProps getAdditionalProps() {
return additionalProps;
}
}