Definitively. That for sure will cause a problem, because each entry
point is like a partition in the data set space.
To make this work, just use the "from entry-point":
Number( doubleValue > 1.0 ) *from* *accumulate*(
StockTick( $pr : price, symbol == "IBM" ) over window:time( 5m )
from entry-point "StockTick stream",
average( $pr ) )
[]s
Edson
2009/5/27 Chris Richmond <crichm...@referentia.com>
> I think the problem is that the stockticks aren’t being processed unless
> I use the:
>
>
>
> From entry-point “StockTick stream”
>
>
>
> But I can’t combine “from accumulate” with that from statement
> successfully in that sample I sent. I think that is the problem . The
> sample I sent, none of those ever get processed since it is not looking at
> the proper entry point…
>
>
>
>
>
>
>
>
>
>
> ------------------------------
>
> *From:* rules-users-boun...@lists.jboss.org [mailto:
> rules-users-boun...@lists.jboss.org] *On Behalf Of *Michal Bali
> *Sent:* Wednesday, May 27, 2009 11:09 AM
> *To:* Rules Users List
> *Subject:* Re: [rules-users] keeping running stats
>
>
>
> Hi Chris,
>
>
> You can use 'accumulate' with sliding time window. Have a look here
> http://downloads.jboss.com/drools/docs/5.0.1.26597.FINAL/drools-fusion/html/ch02.html#d0e1169
>
> rule "Sound the alarm in case temperature rises above threshold"
>
> when
>
> TemperatureThreshold( $max : max )
>
> Number( doubleValue > $max ) from accumulate(
>
> SensorReading( $temp : temperature ) over window:time( 10m ),
>
> average( $temp ) )
>
> then
>
> // sound the alarm
>
> end
>
> The engine will automatically discard any SensorReading older than 10
> minutes and keep the calculated average consistent.
>
> Is that what you're looking for?
>
> Michal
>
> 2009/5/27 Chris Richmond <crichm...@referentia.com>
>
> Hello,
>
>
>
> I have modified the stockTicker fusion example to keep some running stats,
> you can see from the rule snippet below that it injects a stats object based
> on the symbol then matches them as updates come in later. You can see for
> now I am just updating the running counts and outputting the readings count
> on each stock tick and this works fine.
>
>
>
> What I would like to do however is only have the running averages,stats
> object reflect stock ticks that are still in memory….essentiall only stock
> tick items that have not expired. As it is now the count just keeps growing
> and growing, I want the count to only reflect the stock ticks within the
> expiration time in the past for stock ticks, but I cannot figure out how to
> make this happen? Could anyone give me a pointer on how to do this? How
> to make the stats object only reflect those stock ticks that have not
> expired? I do not know the strategy for this.
>
>
>
> Thanks,
>
> Chris
>
>
>
> # tells the engine that a StockTick instance will assume the
>
> # role (semantics) of events and that the default retention
>
> # policy will be 2 minutes
>
> *declare* StockTick
>
> @role( event )
>
> @expires( 1m )
>
> *end*
>
>
>
> # One can even declare helper facts to make rules easier and
>
> # simpler to write and maintain
>
> *declare* Statistics
>
> symbol : String @key()
>
> average : *double*
>
> readings : *int*
>
> total : *double*
>
> *end*
>
>
>
> *rule* "Setup statistics"
>
> *when*
>
> $c : Company( $s : symbol )
>
> *not*( Statistics( symbol == $s ) )
>
> *then*
>
> Statistics s = *new* Statistics();
>
> s.symbol = $s;
>
> s.readings = s.readings + 1;
>
> *insert*( s );
>
>
>
> *end*
>
>
>
>
>
>
>
> # a simple rule to show that it is possible to join
>
> # events from an entry-point (stream) with facts
>
> # present in the working memory
>
> *rule* "Update stock stats"
>
> *agenda-group* "evaluation"
>
> *lock-on-active*
>
> *when*
>
>
>
> $cp : Company( $sb : symbol )
>
> $st : StockTick( symbol == $sb, $pr : price ) *from* entry-point
> "StockTick
> stream"
>
>
>
> $stats : Statistics( symbol == $sb )
>
>
>
> *then*
>
>
>
> *modify*( $stats ) { readings = readings + 1};
>
> System.err.println($stats.symbol + "readings: " + $stats.readings);
>
> // This shows an update on working memory facts with data from joined
> events
>
> //modify( $cp ) { currentPrice = $pr }
>
>
>
> // Although events are considered immutable, a common pattern is to
> use a class
>
> // to represent an event and enrich that event instance with data
> derived from other facts/events.
>
> // Bellow we "enrich" the event instance with the percentual change in
> the price,
>
> // based on the previous price
>
> //modify( $st ) { delta = $cp.delta }
>
> //modify( $st ) { readings = 5 }
>
> //System.out.println($st.delta)
>
> *end*
>
>
> _______________________________________________
> rules-users mailing list
> rules-users@lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
> _______________________________________________
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> rules-users@lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
--
Edson Tirelli
JBoss Drools Core Development
JBoss, a division of Red Hat @ www.jboss.com
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