[rules-users] Why this rule fires immediately ?

[Wolfgang Laun]

First time around I also stumbled over this, especially because the
documention fails to describe the actual behaviour, which is certainly not
intuitive. All uses of "length n" that I know *do not* include things of
length n-1, n-2,... 1. Imagine going into a shop and asking for a belt of
length 60" and getting one of 12". A Java array of length 10 isn't 3 or 5 or
9 elements long. Many mathematical procedures that use a data window of
length n must avoid shorter samples, or use different treatment, e.g., an
initial value problem, or statistical evaluation.

-W


On 18 October 2011 23:33, Mark Proctor <mproctor at codehaus.org> wrote:

> Think about the logic you have written.
>
> length(3) does not mean that it must have 3, but that it is the last
> three. So it could be 0, 1, 2 or 3 in length.
>
> As soon s you have 1, 2, or 3 insertions if any one of those creates an
> average of > 30 the rule fires.
>
> So you are inserting  a ZZZBean that creates an average, even if it's an
> average with a count of 1, over 30.
>
> Mark
> On 18/10/2011 07:20, eskomk wrote:
> > Hi all,
> >
> > Here is the rule:
> >
> > CLIP -->
> > rule "ZZZOver30" dialect "mvel"
> >
> > when
> >      $tsb : ZZZBean($prof : profileID)
> >      $avg : Number( doubleValue>  30 ) from accumulate(
> >          ZZZBean( $tempr : temperature, profileID == $prof) over
> > window:length( 3 ),
> >          average( $tempr ) )
> > then
> >      // do something
> > end
> > CLIP<--
> >
> > The intention as you can see is that the rule fires if the average
> > temperature rises above 30 degrees (of Celsius) in some measuring period.
> > For testing purposes the rule takes a specific number of temperatures
> > (window:length), in production environment the window will be time
> > (window:time(Xm)).
> >
> > My question is, why this rule fires immediately after drools-expert is
> > started ?
> > Is there something wrong in syntax ?
> >
> > In startup there are obviously no objects of this kind (ZZZBean) in
> Working
> > Set's memory, so it really shouldn't fire.
> >
> > We are running Drools ver. 5.1.1 as a web service on top of apache, and
> the
> > facts (events) are fed to Drools via REST interface as XML.
> >
> > thanks and regards,
> > Esko
> > -----
> > Esko Hujanen
> > www.ebsolut.fi
> >
> >
> > --
> > View this message in context:
> http://drools.46999.n3.nabble.com/Why-this-rule-fires-immediately-tp3430427p3430427.html
> > Sent from the Drools: User forum mailing list archive at Nabble.com.
> > _______________________________________________
> > rules-users mailing list
> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
>
>
> _______________________________________________
> 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/20111019/cb3a0277/attachment.html