训练分类或回归模型

本页面介绍如何使用 Google Cloud 控制台或 Vertex AI API 根据表格数据集训练分类或回归模型。

准备工作

在训练模型之前,您必须先完成以下操作:

训练模型

Google Cloud 控制台

  1. 在 Google Cloud 控制台的 Vertex AI 部分中,前往数据集页面。

    转到“数据集”页面

  2. 点击要用于训练模型的数据集的名称,以打开其详情页面。

  3. 如果您的数据类型使用注释集,请选择要用于此模型的注释集。

  4. 点击训练新模型

  5. 选择其他

  6. 训练新模型页面中,完成以下步骤:

    1. 选择模型训练方法。

      • AutoML 非常适合各种用例。

      点击继续

    2. 输入新模型的显示名。

    3. 选择目标列。

      目标列是模型将预测的值。

      详细了解目标列要求

    4. 可选:如需将测试数据集导出到 BigQuery,请选中将测试数据集导出到 BigQuery 并提供表的名称。

    5. 可选:如需选择如何在训练集、测试集和验证集之间拆分数据,请打开高级选项。您可以从以下数据拆分选项中进行选择:

      • 随机(默认):Vertex AI 会随机选择与每个数据集关联的行。默认情况下,Vertex AI 选择 80% 的数据行分配给训练集、10% 分配给验证集、10% 分配给测试集。
      • 手动:Vertex AI 会根据数据拆分列中的值为每个数据集选择数据行。提供数据拆分列的名称。
      • 按时间顺序:Vertex AI 根据时间列中的时间戳拆分数据。提供时间列的名称。

      详细了解数据拆分

    6. 点击继续

    7. 可选:点击生成统计信息。生成统计信息会填充转换下拉菜单。

    8. 在“训练选项”页面上,查看列列表,并从训练中排除任何不应用于训练模型的列。

    9. 查看为包含的特征选择的转换,以及是否允许无效数据,并进行任何所需更新。

      详细了解转换无效数据

    10. 如果要指定权重列,或更改默认的优化目标,请打开高级选项并进行选择。

      详细了解权重列优化目标

    11. 点击继续

    12. 计算和价格窗口中,配置如下:

      输入模型训练的最大小时数。

      此设置有助于限制训练费用。实际所用的时间可能超过此值,因为创建新模型涉及其他操作。

      建议的训练时间与训练数据的大小有关。 下表按行数显示了建议的训练时间范围;列数较多则所需训练时间更长。

      建议的训练时间
      少于 10 万 1 - 3 小时
      10 万 - 100 万 1 - 6 小时
      100 万 - 1000 万 1 - 12 小时
      超过 1000 万 3 - 24 小时
      如需了解训练价格,请参阅价格页面

    13. 点击开始训练

      模型训练可能需要几个小时,具体取决于数据的大小和复杂性,以及训练预算(如果指定)。您可以关闭此标签页,稍后再返回。模型完成训练后,您会收到电子邮件。

API

选择表格数据类型目标。

分类

选择语言或环境标签页:

REST

您可以使用 trainingPipelines.create 命令训练模型。

训练模型。

在使用任何请求数据之前,请先进行以下替换:

  • LOCATION:您的区域。
  • PROJECT:您的项目 ID
  • TRAININGPIPELINE_DISPLAY_NAME:为此操作创建的训练流水线的显示名称。
  • TARGET_COLUMN:您希望此模型预测的列(值)。
  • WEIGHT_COLUMN:(可选)权重列。了解详情
  • TRAINING_BUDGET:您希望模型训练的最长时间,以毫节点时为单位(1,000 毫节点时等于一节点时)。
  • OPTIMIZATION_OBJECTIVE:仅当您不希望预测类型的默认优化目标时,才需要。了解详情
  • TRANSFORMATION_TYPE:将为用于训练模型的每一列提供转换类型。了解详情
  • COLUMN_NAME:具有指定转换类型的列的名称。必须指定用于训练模型的每一列。
  • MODEL_DISPLAY_NAME:新训练模型的显示名称。
  • DATASET_ID:训练数据集的 ID。
  • 您可以提供 Split 对象来控制数据拆分。如需了解如何控制数据拆分,请参阅使用 REST 控制数据拆分
  • PROJECT_NUMBER:自动生成的项目编号

HTTP 方法和网址:

POST https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT/locations/LOCATION/trainingPipelines

请求 JSON 正文:

{
    "displayName": "TRAININGPIPELINE_DISPLAY_NAME",
    "trainingTaskDefinition": "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tabular_1.0.0.yaml",
    "trainingTaskInputs": {
        "targetColumn": "TARGET_COLUMN",
        "weightColumn": "WEIGHT_COLUMN",
        "predictionType": "classification",
        "trainBudgetMilliNodeHours": TRAINING_BUDGET,
        "optimizationObjective": "OPTIMIZATION_OBJECTIVE",
        "transformations": [
            {"TRANSFORMATION_TYPE_1":  {"column_name" : "COLUMN_NAME_1"} },
            {"TRANSFORMATION_TYPE_2":  {"column_name" : "COLUMN_NAME_2"} },
            ...
    },
    "modelToUpload": {"displayName": "MODEL_DISPLAY_NAME"},
    "inputDataConfig": {
      "datasetId": "DATASET_ID",
    }
}

如需发送您的请求,请展开以下选项之一:

您应该收到类似以下内容的 JSON 响应:

{
  "name": "projects/PROJECT_NUMBER/locations/us-central1/trainingPipelines/4567",
  "displayName": "myModelName",
  "trainingTaskDefinition": "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tabular_1.0.0.yaml",
  "modelToUpload": {
    "displayName": "myModelName"
  },
  "state": "PIPELINE_STATE_PENDING",
  "createTime": "2020-08-18T01:22:57.479336Z",
  "updateTime": "2020-08-18T01:22:57.479336Z"
}

Java

在尝试此示例之前,请按照《Vertex AI 快速入门:使用客户端库》中的 Java 设置说明执行操作。如需了解详情,请参阅 Vertex AI Java API 参考文档

如需向 Vertex AI 进行身份验证,请设置应用默认凭据。 如需了解详情,请参阅为本地开发环境设置身份验证


import com.google.cloud.aiplatform.util.ValueConverter;
import com.google.cloud.aiplatform.v1.DeployedModelRef;
import com.google.cloud.aiplatform.v1.EnvVar;
import com.google.cloud.aiplatform.v1.FilterSplit;
import com.google.cloud.aiplatform.v1.FractionSplit;
import com.google.cloud.aiplatform.v1.InputDataConfig;
import com.google.cloud.aiplatform.v1.LocationName;
import com.google.cloud.aiplatform.v1.Model;
import com.google.cloud.aiplatform.v1.ModelContainerSpec;
import com.google.cloud.aiplatform.v1.PipelineServiceClient;
import com.google.cloud.aiplatform.v1.PipelineServiceSettings;
import com.google.cloud.aiplatform.v1.Port;
import com.google.cloud.aiplatform.v1.PredefinedSplit;
import com.google.cloud.aiplatform.v1.PredictSchemata;
import com.google.cloud.aiplatform.v1.TimestampSplit;
import com.google.cloud.aiplatform.v1.TrainingPipeline;
import com.google.cloud.aiplatform.v1.schema.trainingjob.definition.AutoMlTablesInputs;
import com.google.cloud.aiplatform.v1.schema.trainingjob.definition.AutoMlTablesInputs.Transformation;
import com.google.cloud.aiplatform.v1.schema.trainingjob.definition.AutoMlTablesInputs.Transformation.AutoTransformation;
import com.google.rpc.Status;
import java.io.IOException;
import java.util.ArrayList;

public class CreateTrainingPipelineTabularClassificationSample {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String project = "YOUR_PROJECT_ID";
    String modelDisplayName = "YOUR_DATASET_DISPLAY_NAME";
    String datasetId = "YOUR_DATASET_ID";
    String targetColumn = "TARGET_COLUMN";
    createTrainingPipelineTableClassification(project, modelDisplayName, datasetId, targetColumn);
  }

  static void createTrainingPipelineTableClassification(
      String project, String modelDisplayName, String datasetId, String targetColumn)
      throws IOException {
    PipelineServiceSettings pipelineServiceSettings =
        PipelineServiceSettings.newBuilder()
            .setEndpoint("us-central1-aiplatform.googleapis.com:443")
            .build();

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (PipelineServiceClient pipelineServiceClient =
        PipelineServiceClient.create(pipelineServiceSettings)) {
      String location = "us-central1";
      LocationName locationName = LocationName.of(project, location);
      String trainingTaskDefinition =
          "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tables_1.0.0.yaml";

      // Set the columns used for training and their data types
      Transformation transformation1 =
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("sepal_width").build())
              .build();
      Transformation transformation2 =
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("sepal_length").build())
              .build();
      Transformation transformation3 =
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("petal_length").build())
              .build();
      Transformation transformation4 =
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("petal_width").build())
              .build();

      ArrayList<Transformation> transformationArrayList = new ArrayList<>();
      transformationArrayList.add(transformation1);
      transformationArrayList.add(transformation2);
      transformationArrayList.add(transformation3);
      transformationArrayList.add(transformation4);

      AutoMlTablesInputs autoMlTablesInputs =
          AutoMlTablesInputs.newBuilder()
              .setTargetColumn(targetColumn)
              .setPredictionType("classification")
              .addAllTransformations(transformationArrayList)
              .setTrainBudgetMilliNodeHours(8000)
              .build();

      FractionSplit fractionSplit =
          FractionSplit.newBuilder()
              .setTrainingFraction(0.8)
              .setValidationFraction(0.1)
              .setTestFraction(0.1)
              .build();

      InputDataConfig inputDataConfig =
          InputDataConfig.newBuilder()
              .setDatasetId(datasetId)
              .setFractionSplit(fractionSplit)
              .build();
      Model modelToUpload = Model.newBuilder().setDisplayName(modelDisplayName).build();

      TrainingPipeline trainingPipeline =
          TrainingPipeline.newBuilder()
              .setDisplayName(modelDisplayName)
              .setTrainingTaskDefinition(trainingTaskDefinition)
              .setTrainingTaskInputs(ValueConverter.toValue(autoMlTablesInputs))
              .setInputDataConfig(inputDataConfig)
              .setModelToUpload(modelToUpload)
              .build();

      TrainingPipeline trainingPipelineResponse =
          pipelineServiceClient.createTrainingPipeline(locationName, trainingPipeline);

      System.out.println("Create Training Pipeline Tabular Classification Response");
      System.out.format("\tName: %s\n", trainingPipelineResponse.getName());
      System.out.format("\tDisplay Name: %s\n", trainingPipelineResponse.getDisplayName());
      System.out.format(
          "\tTraining Task Definition: %s\n", trainingPipelineResponse.getTrainingTaskDefinition());
      System.out.format(
          "\tTraining Task Inputs: %s\n", trainingPipelineResponse.getTrainingTaskInputs());
      System.out.format(
          "\tTraining Task Metadata: %s\n", trainingPipelineResponse.getTrainingTaskMetadata());

      System.out.format("\tState: %s\n", trainingPipelineResponse.getState());
      System.out.format("\tCreate Time: %s\n", trainingPipelineResponse.getCreateTime());
      System.out.format("\tStart Time: %s\n", trainingPipelineResponse.getStartTime());
      System.out.format("\tEnd Time: %s\n", trainingPipelineResponse.getEndTime());
      System.out.format("\tUpdate Time: %s\n", trainingPipelineResponse.getUpdateTime());
      System.out.format("\tLabels: %s\n", trainingPipelineResponse.getLabelsMap());

      InputDataConfig inputDataConfigResponse = trainingPipelineResponse.getInputDataConfig();
      System.out.println("\tInput Data Config");
      System.out.format("\t\tDataset Id: %s\n", inputDataConfigResponse.getDatasetId());
      System.out.format(
          "\t\tAnnotations Filter: %s\n", inputDataConfigResponse.getAnnotationsFilter());

      FractionSplit fractionSplitResponse = inputDataConfigResponse.getFractionSplit();
      System.out.println("\t\tFraction Split");
      System.out.format(
          "\t\t\tTraining Fraction: %s\n", fractionSplitResponse.getTrainingFraction());
      System.out.format(
          "\t\t\tValidation Fraction: %s\n", fractionSplitResponse.getValidationFraction());
      System.out.format("\t\t\tTest Fraction: %s\n", fractionSplitResponse.getTestFraction());

      FilterSplit filterSplit = inputDataConfigResponse.getFilterSplit();
      System.out.println("\t\tFilter Split");
      System.out.format("\t\t\tTraining Fraction: %s\n", filterSplit.getTrainingFilter());
      System.out.format("\t\t\tValidation Fraction: %s\n", filterSplit.getValidationFilter());
      System.out.format("\t\t\tTest Fraction: %s\n", filterSplit.getTestFilter());

      PredefinedSplit predefinedSplit = inputDataConfigResponse.getPredefinedSplit();
      System.out.println("\t\tPredefined Split");
      System.out.format("\t\t\tKey: %s\n", predefinedSplit.getKey());

      TimestampSplit timestampSplit = inputDataConfigResponse.getTimestampSplit();
      System.out.println("\t\tTimestamp Split");
      System.out.format("\t\t\tTraining Fraction: %s\n", timestampSplit.getTrainingFraction());
      System.out.format("\t\t\tValidation Fraction: %s\n", timestampSplit.getValidationFraction());
      System.out.format("\t\t\tTest Fraction: %s\n", timestampSplit.getTestFraction());
      System.out.format("\t\t\tKey: %s\n", timestampSplit.getKey());

      Model modelResponse = trainingPipelineResponse.getModelToUpload();
      System.out.println("\tModel To Upload");
      System.out.format("\t\tName: %s\n", modelResponse.getName());
      System.out.format("\t\tDisplay Name: %s\n", modelResponse.getDisplayName());
      System.out.format("\t\tDescription: %s\n", modelResponse.getDescription());
      System.out.format("\t\tMetadata Schema Uri: %s\n", modelResponse.getMetadataSchemaUri());
      System.out.format("\t\tMeta Data: %s\n", modelResponse.getMetadata());
      System.out.format("\t\tTraining Pipeline: %s\n", modelResponse.getTrainingPipeline());
      System.out.format("\t\tArtifact Uri: %s\n", modelResponse.getArtifactUri());

      System.out.format(
          "\t\tSupported Deployment Resources Types: %s\n",
          modelResponse.getSupportedDeploymentResourcesTypesList().toString());
      System.out.format(
          "\t\tSupported Input Storage Formats: %s\n",
          modelResponse.getSupportedInputStorageFormatsList().toString());
      System.out.format(
          "\t\tSupported Output Storage Formats: %s\n",
          modelResponse.getSupportedOutputStorageFormatsList().toString());

      System.out.format("\t\tCreate Time: %s\n", modelResponse.getCreateTime());
      System.out.format("\t\tUpdate Time: %s\n", modelResponse.getUpdateTime());
      System.out.format("\t\tLables: %s\n", modelResponse.getLabelsMap());
      PredictSchemata predictSchemata = modelResponse.getPredictSchemata();

      System.out.println("\tPredict Schemata");
      System.out.format("\t\tInstance Schema Uri: %s\n", predictSchemata.getInstanceSchemaUri());
      System.out.format(
          "\t\tParameters Schema Uri: %s\n", predictSchemata.getParametersSchemaUri());
      System.out.format(
          "\t\tPrediction Schema Uri: %s\n", predictSchemata.getPredictionSchemaUri());

      for (Model.ExportFormat supportedExportFormat :
          modelResponse.getSupportedExportFormatsList()) {
        System.out.println("\tSupported Export Format");
        System.out.format("\t\tId: %s\n", supportedExportFormat.getId());
      }
      ModelContainerSpec containerSpec = modelResponse.getContainerSpec();

      System.out.println("\tContainer Spec");
      System.out.format("\t\tImage Uri: %s\n", containerSpec.getImageUri());
      System.out.format("\t\tCommand: %s\n", containerSpec.getCommandList());
      System.out.format("\t\tArgs: %s\n", containerSpec.getArgsList());
      System.out.format("\t\tPredict Route: %s\n", containerSpec.getPredictRoute());
      System.out.format("\t\tHealth Route: %s\n", containerSpec.getHealthRoute());

      for (EnvVar envVar : containerSpec.getEnvList()) {
        System.out.println("\t\tEnv");
        System.out.format("\t\t\tName: %s\n", envVar.getName());
        System.out.format("\t\t\tValue: %s\n", envVar.getValue());
      }

      for (Port port : containerSpec.getPortsList()) {
        System.out.println("\t\tPort");
        System.out.format("\t\t\tContainer Port: %s\n", port.getContainerPort());
      }

      for (DeployedModelRef deployedModelRef : modelResponse.getDeployedModelsList()) {
        System.out.println("\tDeployed Model");
        System.out.format("\t\tEndpoint: %s\n", deployedModelRef.getEndpoint());
        System.out.format("\t\tDeployed Model Id: %s\n", deployedModelRef.getDeployedModelId());
      }

      Status status = trainingPipelineResponse.getError();
      System.out.println("\tError");
      System.out.format("\t\tCode: %s\n", status.getCode());
      System.out.format("\t\tMessage: %s\n", status.getMessage());
    }
  }
}

Node.js

在尝试此示例之前,请按照《Vertex AI 快速入门:使用客户端库》中的 Node.js 设置说明执行操作。如需了解详情,请参阅 Vertex AI Node.js API 参考文档

如需向 Vertex AI 进行身份验证,请设置应用默认凭据。 如需了解详情,请参阅为本地开发环境设置身份验证

/**
 * TODO(developer): Uncomment these variables before running the sample.\
 * (Not necessary if passing values as arguments)
 */

// const datasetId = 'YOUR_DATASET_ID';
// const modelDisplayName = 'YOUR_MODEL_DISPLAY_NAME';
// const trainingPipelineDisplayName = 'YOUR_TRAINING_PIPELINE_DISPLAY_NAME';
// const targetColumn = 'YOUR_TARGET_COLUMN';
// const project = 'YOUR_PROJECT_ID';
// const location = 'YOUR_PROJECT_LOCATION';
const aiplatform = require('@google-cloud/aiplatform');
const {definition} =
  aiplatform.protos.google.cloud.aiplatform.v1.schema.trainingjob;

// Imports the Google Cloud Pipeline Service Client library
const {PipelineServiceClient} = aiplatform.v1;
// Specifies the location of the api endpoint
const clientOptions = {
  apiEndpoint: 'us-central1-aiplatform.googleapis.com',
};

// Instantiates a client
const pipelineServiceClient = new PipelineServiceClient(clientOptions);

async function createTrainingPipelineTablesClassification() {
  // Configure the parent resource
  const parent = `projects/${project}/locations/${location}`;

  const transformations = [
    {auto: {column_name: 'sepal_width'}},
    {auto: {column_name: 'sepal_length'}},
    {auto: {column_name: 'petal_length'}},
    {auto: {column_name: 'petal_width'}},
  ];
  const trainingTaskInputsObj = new definition.AutoMlTablesInputs({
    targetColumn: targetColumn,
    predictionType: 'classification',
    transformations: transformations,
    trainBudgetMilliNodeHours: 8000,
    disableEarlyStopping: false,
    optimizationObjective: 'minimize-log-loss',
  });
  const trainingTaskInputs = trainingTaskInputsObj.toValue();

  const modelToUpload = {displayName: modelDisplayName};
  const inputDataConfig = {
    datasetId: datasetId,
    fractionSplit: {
      trainingFraction: 0.8,
      validationFraction: 0.1,
      testFraction: 0.1,
    },
  };
  const trainingPipeline = {
    displayName: trainingPipelineDisplayName,
    trainingTaskDefinition:
      'gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tables_1.0.0.yaml',
    trainingTaskInputs,
    inputDataConfig,
    modelToUpload,
  };
  const request = {
    parent,
    trainingPipeline,
  };

  // Create training pipeline request
  const [response] =
    await pipelineServiceClient.createTrainingPipeline(request);

  console.log('Create training pipeline tabular classification response');
  console.log(`Name : ${response.name}`);
  console.log('Raw response:');
  console.log(JSON.stringify(response, null, 2));
}
createTrainingPipelineTablesClassification();

Python

如需了解如何安装或更新 Python,请参阅安装 Python 版 Vertex AI SDK。 如需了解详情,请参阅 Python API 参考文档

def create_training_pipeline_tabular_classification_sample(
    project: str,
    display_name: str,
    dataset_id: str,
    location: str = "us-central1",
    model_display_name: str = None,
    target_column: str = "target_column",
    training_fraction_split: float = 0.8,
    validation_fraction_split: float = 0.1,
    test_fraction_split: float = 0.1,
    budget_milli_node_hours: int = 8000,
    disable_early_stopping: bool = False,
    sync: bool = True,
):
    aiplatform.init(project=project, location=location)

    tabular_classification_job = aiplatform.AutoMLTabularTrainingJob(
        display_name=display_name, optimization_prediction_type="classification"
    )

    my_tabular_dataset = aiplatform.TabularDataset(dataset_name=dataset_id)

    model = tabular_classification_job.run(
        dataset=my_tabular_dataset,
        target_column=target_column,
        training_fraction_split=training_fraction_split,
        validation_fraction_split=validation_fraction_split,
        test_fraction_split=test_fraction_split,
        budget_milli_node_hours=budget_milli_node_hours,
        model_display_name=model_display_name,
        disable_early_stopping=disable_early_stopping,
        sync=sync,
    )

    model.wait()

    print(model.display_name)
    print(model.resource_name)
    print(model.uri)
    return model

回归

选择语言或环境标签页:

REST

您可以使用 trainingPipelines.create 命令训练模型。

训练模型。

在使用任何请求数据之前,请先进行以下替换:

  • LOCATION:您的区域。
  • PROJECT:您的项目 ID
  • TRAININGPIPELINE_DISPLAY_NAME:为此操作创建的训练流水线的显示名称。
  • TARGET_COLUMN:您希望此模型预测的列(值)。
  • WEIGHT_COLUMN:(可选)权重列。了解详情
  • TRAINING_BUDGET:您希望模型训练的最长时间,以毫节点时为单位(1,000 毫节点时等于一节点时)。
  • OPTIMIZATION_OBJECTIVE:仅当您不希望预测类型的默认优化目标时,才需要。了解详情
  • TRANSFORMATION_TYPE:将为用于训练模型的每一列提供转换类型。了解详情
  • COLUMN_NAME:具有指定转换类型的列的名称。必须指定用于训练模型的每一列。
  • MODEL_DISPLAY_NAME:新训练模型的显示名称。
  • DATASET_ID:训练数据集的 ID。
  • 您可以提供 Split 对象来控制数据拆分。如需了解如何控制数据拆分,请参阅使用 REST 控制数据拆分
  • PROJECT_NUMBER:自动生成的项目编号

HTTP 方法和网址:

POST https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT/locations/LOCATION/trainingPipelines

请求 JSON 正文:

{
    "displayName": "TRAININGPIPELINE_DISPLAY_NAME",
    "trainingTaskDefinition": "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tabular_1.0.0.yaml",
    "trainingTaskInputs": {
        "targetColumn": "TARGET_COLUMN",
        "weightColumn": "WEIGHT_COLUMN",
        "predictionType": "regression",
        "trainBudgetMilliNodeHours": TRAINING_BUDGET,
        "optimizationObjective": "OPTIMIZATION_OBJECTIVE",
        "transformations": [
            {"TRANSFORMATION_TYPE_1":  {"column_name" : "COLUMN_NAME_1"} },
            {"TRANSFORMATION_TYPE_2":  {"column_name" : "COLUMN_NAME_2"} },
            ...
    },
    "modelToUpload": {"displayName": "MODEL_DISPLAY_NAME"},
    "inputDataConfig": {
      "datasetId": "DATASET_ID",
    }
}

如需发送您的请求,请展开以下选项之一:

您应该收到类似以下内容的 JSON 响应:

{
  "name": "projects/PROJECT_NUMBER/locations/us-central1/trainingPipelines/4567",
  "displayName": "myModelName",
  "trainingTaskDefinition": "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tabular_1.0.0.yaml",
  "modelToUpload": {
    "displayName": "myModelName"
  },
  "state": "PIPELINE_STATE_PENDING",
  "createTime": "2020-08-18T01:22:57.479336Z",
  "updateTime": "2020-08-18T01:22:57.479336Z"
}

Java

在尝试此示例之前,请按照《Vertex AI 快速入门:使用客户端库》中的 Java 设置说明执行操作。如需了解详情,请参阅 Vertex AI Java API 参考文档

如需向 Vertex AI 进行身份验证,请设置应用默认凭据。 如需了解详情,请参阅为本地开发环境设置身份验证


import com.google.cloud.aiplatform.util.ValueConverter;
import com.google.cloud.aiplatform.v1.DeployedModelRef;
import com.google.cloud.aiplatform.v1.EnvVar;
import com.google.cloud.aiplatform.v1.FilterSplit;
import com.google.cloud.aiplatform.v1.FractionSplit;
import com.google.cloud.aiplatform.v1.InputDataConfig;
import com.google.cloud.aiplatform.v1.LocationName;
import com.google.cloud.aiplatform.v1.Model;
import com.google.cloud.aiplatform.v1.ModelContainerSpec;
import com.google.cloud.aiplatform.v1.PipelineServiceClient;
import com.google.cloud.aiplatform.v1.PipelineServiceSettings;
import com.google.cloud.aiplatform.v1.Port;
import com.google.cloud.aiplatform.v1.PredefinedSplit;
import com.google.cloud.aiplatform.v1.PredictSchemata;
import com.google.cloud.aiplatform.v1.TimestampSplit;
import com.google.cloud.aiplatform.v1.TrainingPipeline;
import com.google.cloud.aiplatform.v1beta1.schema.trainingjob.definition.AutoMlTablesInputs;
import com.google.cloud.aiplatform.v1beta1.schema.trainingjob.definition.AutoMlTablesInputs.Transformation;
import com.google.cloud.aiplatform.v1beta1.schema.trainingjob.definition.AutoMlTablesInputs.Transformation.AutoTransformation;
import com.google.cloud.aiplatform.v1beta1.schema.trainingjob.definition.AutoMlTablesInputs.Transformation.TimestampTransformation;
import com.google.rpc.Status;
import java.io.IOException;
import java.util.ArrayList;

public class CreateTrainingPipelineTabularRegressionSample {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String project = "YOUR_PROJECT_ID";
    String modelDisplayName = "YOUR_DATASET_DISPLAY_NAME";
    String datasetId = "YOUR_DATASET_ID";
    String targetColumn = "TARGET_COLUMN";
    createTrainingPipelineTableRegression(project, modelDisplayName, datasetId, targetColumn);
  }

  static void createTrainingPipelineTableRegression(
      String project, String modelDisplayName, String datasetId, String targetColumn)
      throws IOException {
    PipelineServiceSettings pipelineServiceSettings =
        PipelineServiceSettings.newBuilder()
            .setEndpoint("us-central1-aiplatform.googleapis.com:443")
            .build();

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (PipelineServiceClient pipelineServiceClient =
        PipelineServiceClient.create(pipelineServiceSettings)) {
      String location = "us-central1";
      LocationName locationName = LocationName.of(project, location);
      String trainingTaskDefinition =
          "gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tables_1.0.0.yaml";

      // Set the columns used for training and their data types
      ArrayList<Transformation> tranformations = new ArrayList<>();
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("STRING_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("INTEGER_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("FLOAT_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("FLOAT_5000unique_REPEATED"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("NUMERIC_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("BOOLEAN_2unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setTimestamp(
                  TimestampTransformation.newBuilder()
                      .setColumnName("TIMESTAMP_1unique_NULLABLE")
                      .setInvalidValuesAllowed(true))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("DATE_1unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(AutoTransformation.newBuilder().setColumnName("TIME_1unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setTimestamp(
                  TimestampTransformation.newBuilder()
                      .setColumnName("DATETIME_1unique_NULLABLE")
                      .setInvalidValuesAllowed(true))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.STRING_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.INTEGER_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.FLOAT_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.FLOAT_5000unique_REQUIRED"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.FLOAT_5000unique_REPEATED"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.NUMERIC_5000unique_NULLABLE"))
              .build());
      tranformations.add(
          Transformation.newBuilder()
              .setAuto(
                  AutoTransformation.newBuilder()
                      .setColumnName("STRUCT_NULLABLE.TIMESTAMP_1unique_NULLABLE"))
              .build());

      AutoMlTablesInputs trainingTaskInputs =
          AutoMlTablesInputs.newBuilder()
              .addAllTransformations(tranformations)
              .setTargetColumn(targetColumn)
              .setPredictionType("regression")
              .setTrainBudgetMilliNodeHours(8000)
              .setDisableEarlyStopping(false)
              // supported regression optimisation objectives: minimize-rmse,
              // minimize-mae, minimize-rmsle
              .setOptimizationObjective("minimize-rmse")
              .build();

      FractionSplit fractionSplit =
          FractionSplit.newBuilder()
              .setTrainingFraction(0.8)
              .setValidationFraction(0.1)
              .setTestFraction(0.1)
              .build();

      InputDataConfig inputDataConfig =
          InputDataConfig.newBuilder()
              .setDatasetId(datasetId)
              .setFractionSplit(fractionSplit)
              .build();
      Model modelToUpload = Model.newBuilder().setDisplayName(modelDisplayName).build();

      TrainingPipeline trainingPipeline =
          TrainingPipeline.newBuilder()
              .setDisplayName(modelDisplayName)
              .setTrainingTaskDefinition(trainingTaskDefinition)
              .setTrainingTaskInputs(ValueConverter.toValue(trainingTaskInputs))
              .setInputDataConfig(inputDataConfig)
              .setModelToUpload(modelToUpload)
              .build();

      TrainingPipeline trainingPipelineResponse =
          pipelineServiceClient.createTrainingPipeline(locationName, trainingPipeline);

      System.out.println("Create Training Pipeline Tabular Regression Response");
      System.out.format("\tName: %s\n", trainingPipelineResponse.getName());
      System.out.format("\tDisplay Name: %s\n", trainingPipelineResponse.getDisplayName());
      System.out.format(
          "\tTraining Task Definition: %s\n", trainingPipelineResponse.getTrainingTaskDefinition());
      System.out.format(
          "\tTraining Task Inputs: %s\n", trainingPipelineResponse.getTrainingTaskInputs());
      System.out.format(
          "\tTraining Task Metadata: %s\n", trainingPipelineResponse.getTrainingTaskMetadata());

      System.out.format("\tState: %s\n", trainingPipelineResponse.getState());
      System.out.format("\tCreate Time: %s\n", trainingPipelineResponse.getCreateTime());
      System.out.format("\tStart Time: %s\n", trainingPipelineResponse.getStartTime());
      System.out.format("\tEnd Time: %s\n", trainingPipelineResponse.getEndTime());
      System.out.format("\tUpdate Time: %s\n", trainingPipelineResponse.getUpdateTime());
      System.out.format("\tLabels: %s\n", trainingPipelineResponse.getLabelsMap());

      InputDataConfig inputDataConfigResponse = trainingPipelineResponse.getInputDataConfig();
      System.out.println("\tInput Data Config");
      System.out.format("\t\tDataset Id: %s\n", inputDataConfigResponse.getDatasetId());
      System.out.format(
          "\t\tAnnotations Filter: %s\n", inputDataConfigResponse.getAnnotationsFilter());

      FractionSplit fractionSplitResponse = inputDataConfigResponse.getFractionSplit();
      System.out.println("\t\tFraction Split");
      System.out.format(
          "\t\t\tTraining Fraction: %s\n", fractionSplitResponse.getTrainingFraction());
      System.out.format(
          "\t\t\tValidation Fraction: %s\n", fractionSplitResponse.getValidationFraction());
      System.out.format("\t\t\tTest Fraction: %s\n", fractionSplitResponse.getTestFraction());

      FilterSplit filterSplit = inputDataConfigResponse.getFilterSplit();
      System.out.println("\t\tFilter Split");
      System.out.format("\t\t\tTraining Fraction: %s\n", filterSplit.getTrainingFilter());
      System.out.format("\t\t\tValidation Fraction: %s\n", filterSplit.getValidationFilter());
      System.out.format("\t\t\tTest Fraction: %s\n", filterSplit.getTestFilter());

      PredefinedSplit predefinedSplit = inputDataConfigResponse.getPredefinedSplit();
      System.out.println("\t\tPredefined Split");
      System.out.format("\t\t\tKey: %s\n", predefinedSplit.getKey());

      TimestampSplit timestampSplit = inputDataConfigResponse.getTimestampSplit();
      System.out.println("\t\tTimestamp Split");
      System.out.format("\t\t\tTraining Fraction: %s\n", timestampSplit.getTrainingFraction());
      System.out.format("\t\t\tValidation Fraction: %s\n", timestampSplit.getValidationFraction());
      System.out.format("\t\t\tTest Fraction: %s\n", timestampSplit.getTestFraction());
      System.out.format("\t\t\tKey: %s\n", timestampSplit.getKey());

      Model modelResponse = trainingPipelineResponse.getModelToUpload();
      System.out.println("\tModel To Upload");
      System.out.format("\t\tName: %s\n", modelResponse.getName());
      System.out.format("\t\tDisplay Name: %s\n", modelResponse.getDisplayName());
      System.out.format("\t\tDescription: %s\n", modelResponse.getDescription());
      System.out.format("\t\tMetadata Schema Uri: %s\n", modelResponse.getMetadataSchemaUri());
      System.out.format("\t\tMeta Data: %s\n", modelResponse.getMetadata());
      System.out.format("\t\tTraining Pipeline: %s\n", modelResponse.getTrainingPipeline());
      System.out.format("\t\tArtifact Uri: %s\n", modelResponse.getArtifactUri());

      System.out.format(
          "\t\tSupported Deployment Resources Types: %s\n",
          modelResponse.getSupportedDeploymentResourcesTypesList().toString());
      System.out.format(
          "\t\tSupported Input Storage Formats: %s\n",
          modelResponse.getSupportedInputStorageFormatsList().toString());
      System.out.format(
          "\t\tSupported Output Storage Formats: %s\n",
          modelResponse.getSupportedOutputStorageFormatsList().toString());

      System.out.format("\t\tCreate Time: %s\n", modelResponse.getCreateTime());
      System.out.format("\t\tUpdate Time: %s\n", modelResponse.getUpdateTime());
      System.out.format("\t\tLables: %s\n", modelResponse.getLabelsMap());
      PredictSchemata predictSchemata = modelResponse.getPredictSchemata();

      System.out.println("\tPredict Schemata");
      System.out.format("\t\tInstance Schema Uri: %s\n", predictSchemata.getInstanceSchemaUri());
      System.out.format(
          "\t\tParameters Schema Uri: %s\n", predictSchemata.getParametersSchemaUri());
      System.out.format(
          "\t\tPrediction Schema Uri: %s\n", predictSchemata.getPredictionSchemaUri());

      for (Model.ExportFormat supportedExportFormat :
          modelResponse.getSupportedExportFormatsList()) {
        System.out.println("\tSupported Export Format");
        System.out.format("\t\tId: %s\n", supportedExportFormat.getId());
      }
      ModelContainerSpec containerSpec = modelResponse.getContainerSpec();

      System.out.println("\tContainer Spec");
      System.out.format("\t\tImage Uri: %s\n", containerSpec.getImageUri());
      System.out.format("\t\tCommand: %s\n", containerSpec.getCommandList());
      System.out.format("\t\tArgs: %s\n", containerSpec.getArgsList());
      System.out.format("\t\tPredict Route: %s\n", containerSpec.getPredictRoute());
      System.out.format("\t\tHealth Route: %s\n", containerSpec.getHealthRoute());

      for (EnvVar envVar : containerSpec.getEnvList()) {
        System.out.println("\t\tEnv");
        System.out.format("\t\t\tName: %s\n", envVar.getName());
        System.out.format("\t\t\tValue: %s\n", envVar.getValue());
      }

      for (Port port : containerSpec.getPortsList()) {
        System.out.println("\t\tPort");
        System.out.format("\t\t\tContainer Port: %s\n", port.getContainerPort());
      }

      for (DeployedModelRef deployedModelRef : modelResponse.getDeployedModelsList()) {
        System.out.println("\tDeployed Model");
        System.out.format("\t\tEndpoint: %s\n", deployedModelRef.getEndpoint());
        System.out.format("\t\tDeployed Model Id: %s\n", deployedModelRef.getDeployedModelId());
      }

      Status status = trainingPipelineResponse.getError();
      System.out.println("\tError");
      System.out.format("\t\tCode: %s\n", status.getCode());
      System.out.format("\t\tMessage: %s\n", status.getMessage());
    }
  }
}

Node.js

在尝试此示例之前,请按照《Vertex AI 快速入门:使用客户端库》中的 Node.js 设置说明执行操作。如需了解详情,请参阅 Vertex AI Node.js API 参考文档

如需向 Vertex AI 进行身份验证,请设置应用默认凭据。 如需了解详情,请参阅为本地开发环境设置身份验证

/**
 * TODO(developer): Uncomment these variables before running the sample.\
 * (Not necessary if passing values as arguments)
 */

// const datasetId = 'YOUR_DATASET_ID';
// const modelDisplayName = 'YOUR_MODEL_DISPLAY_NAME';
// const trainingPipelineDisplayName = 'YOUR_TRAINING_PIPELINE_DISPLAY_NAME';
// const targetColumn = 'YOUR_TARGET_COLUMN';
// const project = 'YOUR_PROJECT_ID';
// const location = 'YOUR_PROJECT_LOCATION';
const aiplatform = require('@google-cloud/aiplatform');
const {definition} =
  aiplatform.protos.google.cloud.aiplatform.v1.schema.trainingjob;

// Imports the Google Cloud Pipeline Service Client library
const {PipelineServiceClient} = aiplatform.v1;
// Specifies the location of the api endpoint
const clientOptions = {
  apiEndpoint: 'us-central1-aiplatform.googleapis.com',
};

// Instantiates a client
const pipelineServiceClient = new PipelineServiceClient(clientOptions);

async function createTrainingPipelineTablesRegression() {
  // Configure the parent resource
  const parent = `projects/${project}/locations/${location}`;

  const transformations = [
    {auto: {column_name: 'STRING_5000unique_NULLABLE'}},
    {auto: {column_name: 'INTEGER_5000unique_NULLABLE'}},
    {auto: {column_name: 'FLOAT_5000unique_NULLABLE'}},
    {auto: {column_name: 'FLOAT_5000unique_REPEATED'}},
    {auto: {column_name: 'NUMERIC_5000unique_NULLABLE'}},
    {auto: {column_name: 'BOOLEAN_2unique_NULLABLE'}},
    {
      timestamp: {
        column_name: 'TIMESTAMP_1unique_NULLABLE',
        invalid_values_allowed: true,
      },
    },
    {auto: {column_name: 'DATE_1unique_NULLABLE'}},
    {auto: {column_name: 'TIME_1unique_NULLABLE'}},
    {
      timestamp: {
        column_name: 'DATETIME_1unique_NULLABLE',
        invalid_values_allowed: true,
      },
    },
    {auto: {column_name: 'STRUCT_NULLABLE.STRING_5000unique_NULLABLE'}},
    {auto: {column_name: 'STRUCT_NULLABLE.INTEGER_5000unique_NULLABLE'}},
    {auto: {column_name: 'STRUCT_NULLABLE.FLOAT_5000unique_NULLABLE'}},
    {auto: {column_name: 'STRUCT_NULLABLE.FLOAT_5000unique_REQUIRED'}},
    {auto: {column_name: 'STRUCT_NULLABLE.FLOAT_5000unique_REPEATED'}},
    {auto: {column_name: 'STRUCT_NULLABLE.NUMERIC_5000unique_NULLABLE'}},
    {auto: {column_name: 'STRUCT_NULLABLE.BOOLEAN_2unique_NULLABLE'}},
    {auto: {column_name: 'STRUCT_NULLABLE.TIMESTAMP_1unique_NULLABLE'}},
  ];

  const trainingTaskInputsObj = new definition.AutoMlTablesInputs({
    transformations,
    targetColumn,
    predictionType: 'regression',
    trainBudgetMilliNodeHours: 8000,
    disableEarlyStopping: false,
    optimizationObjective: 'minimize-rmse',
  });
  const trainingTaskInputs = trainingTaskInputsObj.toValue();

  const modelToUpload = {displayName: modelDisplayName};
  const inputDataConfig = {
    datasetId: datasetId,
    fractionSplit: {
      trainingFraction: 0.8,
      validationFraction: 0.1,
      testFraction: 0.1,
    },
  };
  const trainingPipeline = {
    displayName: trainingPipelineDisplayName,
    trainingTaskDefinition:
      'gs://google-cloud-aiplatform/schema/trainingjob/definition/automl_tables_1.0.0.yaml',
    trainingTaskInputs,
    inputDataConfig,
    modelToUpload,
  };
  const request = {
    parent,
    trainingPipeline,
  };

  // Create training pipeline request
  const [response] =
    await pipelineServiceClient.createTrainingPipeline(request);

  console.log('Create training pipeline tabular regression response');
  console.log(`Name : ${response.name}`);
  console.log('Raw response:');
  console.log(JSON.stringify(response, null, 2));
}
createTrainingPipelineTablesRegression();

Python

如需了解如何安装或更新 Python,请参阅安装 Python 版 Vertex AI SDK。 如需了解详情,请参阅 Python API 参考文档

def create_training_pipeline_tabular_regression_sample(
    project: str,
    display_name: str,
    dataset_id: str,
    location: str = "us-central1",
    model_display_name: str = "my_model",
    target_column: str = "target_column",
    training_fraction_split: float = 0.8,
    validation_fraction_split: float = 0.1,
    test_fraction_split: float = 0.1,
    budget_milli_node_hours: int = 8000,
    disable_early_stopping: bool = False,
    sync: bool = True,
):
    aiplatform.init(project=project, location=location)

    tabular_regression_job = aiplatform.AutoMLTabularTrainingJob(
        display_name=display_name, optimization_prediction_type="regression"
    )

    my_tabular_dataset = aiplatform.TabularDataset(dataset_name=dataset_id)

    model = tabular_regression_job.run(
        dataset=my_tabular_dataset,
        target_column=target_column,
        training_fraction_split=training_fraction_split,
        validation_fraction_split=validation_fraction_split,
        test_fraction_split=test_fraction_split,
        budget_milli_node_hours=budget_milli_node_hours,
        model_display_name=model_display_name,
        disable_early_stopping=disable_early_stopping,
        sync=sync,
    )

    model.wait()

    print(model.display_name)
    print(model.resource_name)
    print(model.uri)
    return model

使用 REST 控制数据拆分

您可以控制在训练集、验证集和测试集之间拆分训练数据的方式。使用 Vertex AI API 时,请使用 Split 对象来确定数据拆分。Split 对象可以包含在 inputDataConfig 对象中作为多种对象类型中的一种,其中每种类型都提供一种不同的训练数据拆分方式。

可用于拆分数据的方法取决于数据类型:

  • FractionSplit

    • TRAINING_FRACTION:要用于训练集的训练数据的比例。
    • VALIDATION_FRACTION:要用于验证集的训练数据的比例。
    • TEST_FRACTION:要用于测试集的训练数据的比例。

    如果指定了任一比例,则必须指定所有比例。这些比例之和必须等于 1.0。了解详情

    "fractionSplit": {
    "trainingFraction": TRAINING_FRACTION,
    "validationFraction": VALIDATION_FRACTION,
    "testFraction": TEST_FRACTION
    },
    

  • PredefinedSplit

    • DATA_SPLIT_COLUMN:包含数据拆分值(TRAINVALIDATIONTEST)的列。

    使用拆分列为每行手动指定数据拆分。 了解详情

    "predefinedSplit": {
      "key": DATA_SPLIT_COLUMN
    },
    
  • TimestampSplit

    • TRAINING_FRACTION:要用于训练集的训练数据的百分比。默认值为 0.80。
    • VALIDATION_FRACTION:要用于验证集的训练数据的百分比。默认值为 0.10。
    • TEST_FRACTION:要用于测试集的训练数据的百分比。默认值为 0.10。
    • TIME_COLUMN:包含时间戳的列。

    如果指定了任一比例,则必须指定所有比例。这些比例之和必须等于 1.0。了解详情

    "timestampSplit": {
      "trainingFraction": TRAINING_FRACTION,
      "validationFraction": VALIDATION_FRACTION,
      "testFraction": TEST_FRACTION,
      "key": TIME_COLUMN
    }
    

分类或回归模型的优化目标

在训练模型时,Vertex AI 会根据模型类型和用于目标列的数据类型选择默认优化目标。

分类模型最适合的情况:
优化目标 API 值 在什么情况下使用该目标
AUC ROC maximize-au-roc 最大化接收者操作特征 (ROC) 曲线下的面积。区分不同的类别。二元分类的默认值。
对数损失 minimize-log-loss 使预测概率尽可能准确。仅限于支持的多类别分类目标。
AUC PR maximize-au-prc 最大化精确率/召回率曲线下的面积。优化不常见类别的预测结果。
特定召回率下的精确率 maximize-precision-at-recall 优化特定召回值下的精确率。
特定精确率下的召回率 maximize-recall-at-precision 优化特定精确率下的召回率。
回归模型最适合的情况:
优化目标 API 值 在什么情况下使用该目标
均方根误差 minimize-rmse 最大限度降低均方根误差 (RMSE)。准确捕捉更多极值。默认值。
MAE minimize-mae 最大限度降低平均绝对误差 (MAE)。将极值视为对模型影响较小的离群值。
RMSLE minimize-rmsle 最大限度降低均方根对数误差 (RMSLE)。根据相对误差而不是绝对误差来判错。适用于预测值和实际值都非常大的情况。

后续步骤