Re: [rules-users] Drools 5.5 divide by 0 exception

Could you expand upon why this is a poor practice? I assumed that if a part of the pattern doesn't match the expression evaluation is terminated laune wrote > I can anticipate the answer where OP says that there is a constraint > restricting argVolume to > 0. However, I don't think that independent > constraints such as we see them in this rule are evaluated as if they > were in a single logical expression, with Java semantics. > > The seductive possibility of binding to a half-baked expression (i.e., > $ratio:(volumeAccumulations["total"]/consolidatdVolume.avgVolume)) > should be discarded. This value can safely be computed on the RHS > where the denominator's value being !=0 is asserted. > > -W > > On 01/11/2013, Stephen Masters < > stephen.masters@ > > wrote: >> Divide by zero exceptions usually occur when you try to divide by zero. >> >> So … first question … is consolidatdVolume.avgVolume ever zero? >> >> >> On 1 Nov 2013, at 16:17, gboro54 < > gboro54@ > > wrote: >> >>> I have rules like the following: >>> >>> rule "Add Baseline to Context if it does not exists exists or not >>> greater >>> then 0" >>> no-loop true >>> when >>> $context:Context($id:id,baselineParticipation==null || >>> >>> baselineParticipation.baselineRatio==null||baselineParticipation.baselineRatio==0) >>> then >>> modify($firm) {setBaselineParticipation(new >>> BaselineParticipation($id,new >>> BigDecimal(0.00485)))}; >>> >>> end >>> >>> rule "Calculate Participation Ratio" >>> no-loop true >>> when >>> >>> $context:Context(consolidatdVolume!=null,consolidatdVolume.avgVolume>0, >>> >>> volumeAccumulations["total"]!=null,volumeAccumulations["total"]>0, >>> >>> $ratio:(volumeAccumulations["total"]/consolidatdVolume.avgVolume)) >>> then >>> ConcurrentMap calculatedRatios=$firm.getCalculatedRatios(); >>> calculatedRatios.put("fparticipationRatio",new BigDecimal($ratio)); >>> modify($firm){setCalculatedRatios(calculatedRatios)}; >>> end >>> >>> Despite the checks I get the following exception and any insight into >>> why >>> would be great: >>> >>> Exception executing consequence for rule "Calculate Firm Participation >>> Ratio" in com.nasdaq.rms.nq.status: java.lang.ArithmeticException: / by >>> zero >>> Exception executing consequence for rule "Calculate Firm Participation >>> Ratio" in com.nasdaq.rms.nq.status: java.lang.ArithmeticException: / by >>> zero >>> at >>> org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39) >>> at >>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1297) >>> at >>> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1221) >>> at >>> org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1456) >>> at >>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710) >>> at >>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:674) >>> at >>> org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230) >>> at >>> com.nasdaq.fq.rms.workflow.processor.rules.PerformanceStatusAssignmentProcessor.doWork(PerformanceStatusAssignmentProcessor.java:156) >>> at >>> com.ften.ssr.workqueue.WorkItemRunnable.run(WorkItemRunnable.java:48) >>> at >>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) >>> at >>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) >>> at java.lang.Thread.run(Thread.java:724) >>> Caused by: java.lang.ArithmeticException: / by zero >>> at ConditionEvaluatorda6271cf5a744b6bbdb9c717cae2edb7.evaluate(Unknown >>> Source) >>> at >>> org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:200) >>> at >>> org.drools.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:157) >>> at org.drools.reteoo.AlphaNode.modifyObject(AlphaNode.java:154) >>> at >>> org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateModifyObject(CompositeObjectSinkAdapter.java:507) >>> at >>> org.drools.reteoo.CompositeObjectSinkAdapter.propagateModifyObject(CompositeObjectSinkAdapter.java:432) >>> at org.drools.reteoo.AlphaNode.modifyObject(AlphaNode.java:157) >>> at >>> org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateModifyObject(CompositeObjectSinkAdapter.java:507) >>> at >>> org.drools.reteoo.CompositeObjectSinkAdapter.propagateModifyObject(CompositeObjectSinkAdapter.java:432) >>> at >>> org.drools.reteoo.ObjectTypeNode.modifyObject(ObjectTypeNode.java:314) >>> at >>> org.drools.reteoo.EntryPointNode.modifyObject(EntryPointNode.java:265) >>> at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:483) >>> at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:383) >>> at >>> org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:337) >>> at >>> com.nasdaq.rms.nq.status.Rule_Calculate_Firm_Participation_Ratio_cfb033f33c2b404fb2bff8e1b9af0175.defaultConsequence(Unknown >>> Source) >>> at >>> com.nasdaq.rms.nq.status.Rule_Calculate_Firm_Participation_Ratio_cfb033f33c2b404fb2bff8e1b9af0175DefaultConsequenceInvokerGenerated.evaluate(Unknown >>> Source) >>> at >>> com.nasdaq.rms.nq.status.Rule_Calculate_Firm_Participation_Ratio_cfb033f33c2b404fb2bff8e1b9af0175DefaultConsequenceInvoker.evaluate(Unknown >>> Source) >>> at >>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287) >>> ... 10 more >>> >>> >>> >>> -- >>> View this message in context: >>> http://drools.46999.n3.nabble.com/Drools-5-5-divide-by-0-exception-tp4026... >>> Sent from the Drools: User forum mailing list archive at Nabble.com. >>> _______________________________________________ >>> rules-users mailing list >>> > rules-users@.jboss >>> https://lists.jboss.org/mailman/listinfo/rules-users >> >> >> _______________________________________________ >> rules-users mailing list >> > rules-users@.jboss >> https://lists.jboss.org/mailman/listinfo/rules-users >> > > _______________________________________________ > rules-users mailing list > rules-users@.jboss > https://lists.jboss.org/mailman/listinfo/rules-users -- View this message in context: http://drools.46999.n3.nabble.com/Drools-5-5-divide-by-0-exception-tp4026... 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