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Why am I getting a NullPointerException?

DravenDraven Member Posts: 3 Learner I
in Help

I'm having trouble identifying an error that tells me there are no obvious errors and to look at the log. All of my data is either integer or binominal. Everyone else in my class was able to use the data, whereas I encountered this problem. I'm on version 10.2. 

Here's the log:

SEVERE: Process failed: operator cannot be executed. Check the log messages...

SEVERE: Here: 

SEVERE:           Process[1] (Process)

SEVERE:            subprocess 'Main Process'

SEVERE:              +- Retrieve EastWestAirlinesNN+_1_-1[1] (Retrieve)

SEVERE:        ==>   +- Cross Validation[1] (Cross Validation)

SEVERE:            subprocess 'Training'

SEVERE:                 |  +- Replace Missing Values[0] (Replace Missing Values)

SEVERE:                 |  +- Neural Net[0] (Neural Net)

SEVERE:            subprocess 'Testing'

SEVERE:                    +- Apply Model[0] (Apply Model)

SEVERE:                    +- Performance (2)[0] (Performance (Binominal Classification))

SEVERE: java.lang.NullPointerException

Best Answer

  • ClaudioKeckClaudioKeck Employee-RapidMiner, Member Posts: 38 Guru
    Solution Accepted
    Hi, Can you try the process again with having the replace missing values operator outside the cross validation? this worked for me. 

Answers

  • ClaudioKeckClaudioKeck Employee-RapidMiner, Member Posts: 38 Guru
    Hi @Draven, 

    Could you please share the Process XML and if possible the data with us? happy to take a look into process.
  • MartinLiebigMartinLiebig Administrator, Moderator, Employee-RapidMiner, RapidMiner Certified Analyst, RapidMiner Certified Expert, University Professor Posts: 3,533 RM Data Scientist
    Hi,
    please also check the rapidminer-studio.log for the stack trace.
    Best,
    Martin
    - Sr. Director Data Solutions, Altair RapidMiner -
    Dortmund, Germany
  • DravenDraven Member Posts: 3 Learner I
    I've attached the data and process XML. 

    Here's the stack trace I found in the rapidminer-studio.log file, though I don't know how to interpret it:

    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE: Here: 
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:           Process[1] (Process)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:            subprocess 'Main Process'
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:              +- Retrieve EastWestAirlinesNN+_1_-1[1] (Retrieve)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:        ==>   +- Cross Validation[1] (Cross Validation)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:            subprocess 'Training'
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:                 |  +- Replace Missing Values[0] (Replace Missing Values)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:                 |  +- Neural Net[0] (Neural Net)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:            subprocess 'Testing'
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:                    +- Apply Model[0] (Apply Model)
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread logProcessTreeList
    SEVERE:                    +- Performance[0] (Performance (Binominal Classification))
    Oct 26, 2023 9:20:33 AM com.rapidminer.gui.ProcessThread run
    SEVERE: java.lang.NullPointerException
    java.lang.NullPointerException
    at com.rapidminer.example.set.StratifiedPartitionBuilder$ExampleIndex.compareTo(StratifiedPartitionBuilder.java:71)
    at com.rapidminer.example.set.StratifiedPartitionBuilder$ExampleIndex.compareTo(StratifiedPartitionBuilder.java:58)
    at java.base/java.util.ComparableTimSort.binarySort(Unknown Source)
    at java.base/java.util.ComparableTimSort.sort(Unknown Source)
    at java.base/java.util.Arrays.sort(Unknown Source)
    at java.base/java.util.Arrays.sort(Unknown Source)
    at java.base/java.util.ArrayList.sort(Unknown Source)
    at java.base/java.util.Collections.sort(Unknown Source)
    at com.rapidminer.example.set.StratifiedPartitionBuilder.createPartitionFromIndices(StratifiedPartitionBuilder.java:201)
    at com.rapidminer.example.set.ColumnStratifiedPartitionBuilder.createEqualPartition(ColumnStratifiedPartitionBuilder.java:125)
    at com.rapidminer.example.set.ColumnStratifiedPartitionBuilder.createPartition(ColumnStratifiedPartitionBuilder.java:109)
    at com.rapidminer.example.set.ImmutablePartition.<init>(ImmutablePartition.java:74)
    at com.rapidminer.example.set.TableSplitter.<init>(TableSplitter.java:195)
    at com.rapidminer.example.set.TableSplitterWithCompatibility.create(TableSplitterWithCompatibility.java:69)
    at com.rapidminer.extension.concurrency.operator.validation.CrossValidationOperator.doTableWork(CrossValidationOperator.java:371)
    at com.rapidminer.extension.concurrency.operator.validation.CrossValidationOperator.doWork(CrossValidationOperator.java:249)
    at com.rapidminer.operator.Operator.execute(Operator.java:1024)
    at com.rapidminer.operator.execution.SimpleUnitExecutor.execute(SimpleUnitExecutor.java:77)
    at com.rapidminer.operator.ExecutionUnit$2.run(ExecutionUnit.java:804)
    at com.rapidminer.operator.ExecutionUnit$2.run(ExecutionUnit.java:799)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at com.rapidminer.operator.ExecutionUnit.execute(ExecutionUnit.java:799)
    at com.rapidminer.operator.OperatorChain.doWork(OperatorChain.java:423)
    at com.rapidminer.operator.Operator.execute(Operator.java:1024)
    at com.rapidminer.Process.executeRoot(Process.java:1476)
    at com.rapidminer.Process.lambda$executeRootInPool$5(Process.java:1452)
    at com.rapidminer.studio.concurrency.internal.AbstractConcurrencyContext$AdaptedCallable.exec(AbstractConcurrencyContext.java:362)
    at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
    at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source)
    at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source)
    at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
    at java.base/java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
  • DravenDraven Member Posts: 3 Learner I
    Worked for me as well, thanks! Any idea why that would create this error?
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