[rules-users] Writing a pattern in which each constraint for an event depends on the previous event

[Wolfgang Laun]

A monotonically decreasing sequence a1, a2,... is one without a[i] < a[j]
for all j > i.

$a : StockTick() over window:time(20s)
 not StockTick(this after $a, price > $a.price) over window:time(20s)

But I think that it's more efficient to keep track of the status of a stock
by its last quote and the last time there was an increase. The arrival of a
new StockTick is matched in a couple of rules with the StockStatus, which is
updated accordingly.

-W




On 28 January 2011 11:25, OlliSee <o.roess at seeburger.de> 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-which-each-constraint-for-an-event-depends-on-the-previous-event-tp2366196p2366196.html
> Sent from the Drools - User mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110128/0bfd7f33/attachment.html