See the current discussion of accumulate functions. That should satisfy your need. GreG On Jan 29, 2011, at 10:18, OlliSee <o.roess(a)seeburger.de&gt; wrote: > > Hello everyone. > > Lets say we have StockTicks... > Is it possible to detect a monotonically decreasing StockTick stream over a > window? > > If I knew the number of events I want to check on, I'd do it this way > > $a : StockTick() over window:time(20s) > $b : StockTick(this after $a, price < $a.price) over window:time(20s) > ... > > But I don't know for how long the StockTick prices continue to decrease.. > I imagine doing something like that > > $list : List(size > 0) from collect(StockTick() over window:time(20s)) > forall($a : StockTick() from $list > $b : StockTick(this after $a, price < $a.price from $list > ) > > That results in a nice exception. > Any idea how to do this work? And more efficiently than my approach? > > Thanks > Oliver > > > > Exception in thread "Thread-1" java.lang.ClassCastException: > org.drools.common.DefaultFactHandle cannot be cast to > org.drools.common.EventFactHandle > at > org.drools.base.evaluators.AfterEvaluatorDefinition$AfterEvaluator.evaluateCachedLeft(AfterEvaluatorDefinition.java:336) > at > org.drools.rule.VariableRestriction.isAllowedCachedLeft(VariableRestriction.java:110) > at > org.drools.rule.VariableConstraint.isAllowedCachedLeft(VariableConstraint.java:115) > at > org.drools.common.DoubleBetaConstraints.isAllowedCachedLeft(DoubleBetaConstraints.java:166) > at > org.drools.reteoo.FromNode.checkConstraintsAndPropagate(FromNode.java:274) > at org.drools.reteoo.FromNode.assertLeftTuple(FromNode.java:138) > at > org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:220) > at > org.drools.reteoo.CompositeLeftTupleSinkAdapter.propagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:81) > at > org.drools.reteoo.FromNode.checkConstraintsAndPropagate(FromNode.java:279) > at org.drools.reteoo.FromNode.assertLeftTuple(FromNode.java:138) > at > org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:220) > at > org.drools.reteoo.CompositeLeftTupleSinkAdapter.propagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:81) > at > org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:662) > at org.drools.reteoo.AccumulateNode.assertObject(AccumulateNode.java:270) > at > org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:450) > at > org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:378) > at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:190) > at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:145) > at > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1187) > at > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1089) > at > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:893) > at > org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:238) > > -- > View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Writing-a-pattern-in-... > Sent from the Drools - User mailing list archive at Nabble.com. > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

@Wolfgang: I guess you are referring to the list I use. Of course I expect them to be ordered by timestamp.

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Yes, the accumulate function itself should maintain the sort internally.

@OlliSee : See the thread titled "How to write a rule that fires when it matches against specific facts in working memory." --- On Sun, 1/30/11, Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; wrote: From: Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; Subject: Re: [rules-users] Writing a pattern in which each event constraint depends on the previous event To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; Date: Sunday, January 30, 2011, 10:25 AM On 30 January 2011 12:55, OlliSee <o.roess(a)seeburger.de&gt; wrote: @Wolfgang: I guess you are referring to the list I use. Of course I expect them to be ordered by timestamp. You sure do, but the question is whether you get them in this order during processing by accumulate. There is no documentation that accumulate passes through a set of selected facts in the order they were inserted. It could just as well be the (random) order of some hash key, or reverse, or whatever. -W -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Writing-a-pattern-in-... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -----Inline Attachment Follows----- _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users