Hello, I'm having trouble using sliding length windows. Either I'm implementing them wrong or I have misunderstood how they're supposed to work. I have a class named Notif: *public class Notif implements Serializable{ ... private String specificProblem; ... public String getSpecificProblem() { return specificProblem; } public void setSpecificProblem(String specificProblem) { this.specificProblem = specificProblem; } }* These Notif's represent my events. I want to know how many Notifs with specificProblem "New ONT" are there in the last 2 received events. My .drl file looks like this: *declare Notif @role( event ) end rule "Rule1" when $event : Notif() $nNewONT : Number() from accumulate ( Notif( specificProblem == "New ONT" ) over window:length(2), count() ) then System.out.println("In the last 2 events there were "+$nNewONT+" events 'New ONT'"); end* My test file: *... session.insert(ONTIsInactive1); session.insert(newONT1); session.insert(ONTIsInactive2); session.insert(newONT2); session.insert(LOKS1); session.insert(LOKS2); session.insert(LOKS3); session.insert(newONT3); session.fireAllRules(); * As you probably can tell by the names, the events I'm looking for are the 2nd, the 4th and the last one. But the output I get is: In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' In the last 2 events there were 2 events 'New ONT' The output I'm looking for is: In the last 2 events there were 0 events 'New ONT' (because the received event is "ONTIsInactive") In the last 2 events there were 1 events 'New ONT' (because the last 2 received events are "ONTIsInactive" and "New ONT") In the last 2 events there were 1 events 'New ONT' (because the last 2 received events are "New ONT" and "ONTIsInactive") ... and so on... What am I doing wrong? Any help would be appreciated! Thanks in advance, Diana -- View this message in context: http://drools.46999.n3.nabble.com/Sliding-Length-Windows-tp3438408p343840... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Hello, Thank you for your response, I understand how the sliding window works now. However, when I use the code you wrote I get the following error: Exception in thread "main" java.lang.RuntimeException: Unable to resolve ObjectType 'List' : [Rule name='Rule2'] Unable to Analyse Expression $last2: [Error: unable to resolve method using strict-mode: java.lang.Object.$last2()] My rule looks like this: rule "Rule2" when $last2: List() from collect( Notif() over window:length(2) ) $nNewONT : Number() from accumulate ( Notif( specificProblem == "New ONT" ) from $last2, count() ) then ... end Do Lists require any additional code?... Thanks in advance, Diana -- View this message in context: http://drools.46999.n3.nabble.com/Sliding-Length-Windows-tp3438408p346743... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users