[I need help!] I am training an LSTM model to predict numerical changes...

[Brucia323]

I'm a newbie and I encountered this bug:

Index 3 out of bounds for length 1
java.lang.ArrayIndexOutOfBoundsException: Index 3 out of bounds for length 1
	at ai.djl.ndarray.types.Shape.get(Shape.java:138)
	at io.zcy.todo.djl.DeepJavaLibrary.lambda$getLSTMModel$5(DeepJavaLibrary.java:87)
	at ai.djl.nn.LambdaBlock.lambda$singleton$0(LambdaBlock.java:83)
	at ai.djl.nn.LambdaBlock.forwardInternal(LambdaBlock.java:106)
	at ai.djl.nn.AbstractBaseBlock.forwardInternal(AbstractBaseBlock.java:126)
	at ai.djl.nn.AbstractBaseBlock.forward(AbstractBaseBlock.java:91)
	at ai.djl.nn.SequentialBlock.forwardInternal(SequentialBlock.java:209)
	at ai.djl.nn.AbstractBaseBlock.forward(AbstractBaseBlock.java:91)
	at ai.djl.training.Trainer.forward(Trainer.java:189)
	at ai.djl.training.EasyTrain.trainSplit(EasyTrain.java:122)
	at ai.djl.training.EasyTrain.trainBatch(EasyTrain.java:110)
	at ai.djl.training.EasyTrain.fit(EasyTrain.java:58)
	at io.zcy.todo.djl.DeepJavaLibrary.lstm(DeepJavaLibrary.java:73)
	at io.zcy.todo.djl.DeepJavaLibraryTest.lstm(DeepJavaLibraryTest.java:17)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:727)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86)
	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(InterceptingExecutableInvoker.java:103)
	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.lambda$invoke$0(InterceptingExecutableInvoker.java:93)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:92)
	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:86)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:217)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:213)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:138)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:68)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
	at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
	at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:99)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:62)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
	at jdk.proxy1/jdk.proxy1.$Proxy2.stop(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:193)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
	at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:113)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:65)
	at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
	at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)
	Suppressed: java.lang.NullPointerException: Cannot invoke "java.lang.Float.floatValue()" because the return value of "ai.djl.training.TrainingResult.getValidateEvaluation(String)" is null
		at io.zcy.todo.djl.DeepJavaLibrary.lambda$setupTrainingConfig$6(DeepJavaLibrary.java:111)
		at ai.djl.training.listener.SaveModelTrainingListener.saveModel(SaveModelTrainingListener.java:151)
		at ai.djl.training.listener.SaveModelTrainingListener.onTrainingEnd(SaveModelTrainingListener.java:90)
		at ai.djl.training.Trainer.lambda$close$2(Trainer.java:331)
		at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
		at ai.djl.training.Trainer.notifyListeners(Trainer.java:285)
		at ai.djl.training.Trainer.close(Trainer.java:331)
		at io.zcy.todo.djl.DeepJavaLibrary.lstm(DeepJavaLibrary.java:69)
		... 86 more

I'm monitoring that input has changed from ND: (1, 1, 5, 1) cpu() float32 to ND: (1) cpu() int32 and this 1 seems to be related to the Sampling I set in ArrayDataset. I would like to know what I should do?

private static Block getLSTMModel() {
  SequentialBlock block = new SequentialBlock();
  block.addSingleton(
      input -> {
        log.info("input: {}", input);
        Shape inputShape = input.getShape();
        long batchSize = inputShape.get(0);
        long channel = inputShape.get(3);
        long time = inputShape.size() / (batchSize * channel);
        return input.reshape(new Shape(batchSize, time, channel));
      });
  block.add(
      new LSTM.Builder()
          .setStateSize(64)
          .setNumLayers(1)
          .optDropRate(0)
          .optReturnState(false)
          .build());
  block.add(BatchNorm.builder().optEpsilon(1e-5f).optMomentum(0.9f).build());
  block.add(Blocks.batchFlattenBlock());
  block.add(Linear.builder().setUnits(10).build());
  return block;
}

Here is my code:

public TrainingResult lstm() throws IOException, TranslateException {
    int[] amounts = [30, 40, 90, 100, 100];
    try (NDManager manager = NDManager.newBaseManager()) {
      NDArray labels = manager.arange(amounts.length);
      NDArray data = manager.create(amounts);
      ArrayDataset arrayDataset =
          new ArrayDataset.Builder().optLabels(labels).setData(data).setSampling(1, false).build();
      arrayDataset.prepare(new ProgressBar());
      try (Model model = Model.newInstance("lstm")) {
        model.setBlock(getLSTMModel());
        DefaultTrainingConfig config = setupTrainingConfig();
        try (Trainer trainer = model.newTrainer(config)) {
          trainer.setMetrics(new Metrics());
          Shape shape = new Shape(1, 1, arrayDataset.size(), 1);
          trainer.initialize(shape);
          EasyTrain.fit(trainer, 1, arrayDataset, null);
          return trainer.getTrainingResult();
        }
      }
    }
  }

  private static Block getLSTMModel() {
    SequentialBlock block = new SequentialBlock();
    block.addSingleton(
        input -> {
          Shape inputShape = input.getShape();
          long batchSize = inputShape.get(0);
          long channel = inputShape.get(3);
          long time = inputShape.size() / (batchSize * channel);
          return input.reshape(new Shape(batchSize, time, channel));
        });
    block.add(
        new LSTM.Builder()
            .setStateSize(64)
            .setNumLayers(1)
            .optDropRate(0)
            .optReturnState(false)
            .build());
    block.add(BatchNorm.builder().optEpsilon(1e-5f).optMomentum(0.9f).build());
    block.add(Blocks.batchFlattenBlock());
    block.add(Linear.builder().setUnits(10).build());
    return block;
  }

  private static DefaultTrainingConfig setupTrainingConfig() {
    String outputDir = "/build/model";
    SaveModelTrainingListener listener = new SaveModelTrainingListener(outputDir);
    listener.setSaveModelCallback(
        trainer -> {
          TrainingResult result = trainer.getTrainingResult();
          Model model = trainer.getModel();
          float accuracy = result.getValidateEvaluation("Accuracy");
          model.setProperty("Accuracy", String.format("%.5f", accuracy));
          model.setProperty("Loss", String.format("%.5f", result.getValidateLoss()));
        });

    return new DefaultTrainingConfig(Loss.softmaxCrossEntropyLoss())
        .addEvaluator(new Accuracy())
        .optDevices(Engine.getInstance().getDevices(1))
        .addTrainingListeners(TrainingListener.Defaults.logging(outputDir))
        .addTrainingListeners(listener);
  }

build.gradle.kts:

implementation("ai.djl.spring:djl-spring-boot-starter-pytorch-auto:0.20")
implementation("ai.djl.spring:djl-spring-boot-starter-autoconfigure:0.20")