Add SamplingKeyColumnName to AutoMLExperiment API

src/Microsoft.ML.AutoML/API/AutoMLExperimentExtension.cs

@@ -57,14 +57,16 @@ public static AutoMLExperiment SetDataset(this AutoMLExperiment experiment, Trai
         /// </summary>
         /// <param name="experiment"><see cref="AutoMLExperiment"/></param>
         /// <param name="dataset">dataset for cross-validation split.</param>
-        /// <param name="fold"></param>
+        /// <param name="fold">number of cross-validation folds</param>
+        /// <param name="samplingKeyColumnName">column name for sampling key</param>
         /// <returns><see cref="AutoMLExperiment"/></returns>
-        public static AutoMLExperiment SetDataset(this AutoMLExperiment experiment, IDataView dataset, int fold = 10)
+        public static AutoMLExperiment SetDataset(this AutoMLExperiment experiment, IDataView dataset, int fold = 10, string samplingKeyColumnName = null)
         {
             var datasetManager = new CrossValidateDatasetManager()
             {
                 Dataset = dataset,
                 Fold = fold,
+                SamplingKeyColumnName = samplingKeyColumnName,
             };
 
             experiment.ServiceCollection.AddSingleton<IDatasetManager>(datasetManager);

src/Microsoft.ML.AutoML/AutoMLExperiment/IDatasetManager.cs

@@ -17,6 +17,8 @@ internal interface ICrossValidateDatasetManager
         int? Fold { get; set; }
 
         IDataView Dataset { get; set; }
+
+        string SamplingKeyColumnName { get; set; }
     }
 
     internal interface ITrainValidateDatasetManager
@@ -38,5 +40,6 @@ internal class CrossValidateDatasetManager : IDatasetManager, ICrossValidateData
         public IDataView Dataset { get; set; }
 
         public int? Fold { get; set; }
+        public string SamplingKeyColumnName { get; set; }
     }
 }

src/Microsoft.ML.AutoML/AutoMLExperiment/Runner/SweepablePipelineRunner.cs

@@ -40,7 +40,7 @@ public TrialResult Run(TrialSettings settings)
             var mlnetPipeline = _pipeline.BuildFromOption(_mLContext, parameter);
             if (_datasetManager is ICrossValidateDatasetManager crossValidateDatasetManager)
             {
-                var datasetSplit = _mLContext!.Data.CrossValidationSplit(crossValidateDatasetManager.Dataset, crossValidateDatasetManager.Fold ?? 5);
+                var datasetSplit = _mLContext!.Data.CrossValidationSplit(crossValidateDatasetManager.Dataset, crossValidateDatasetManager.Fold ?? 5, crossValidateDatasetManager.SamplingKeyColumnName);
                 var metrics = new List<double>();
                 var models = new List<ITransformer>();
                 foreach (var split in datasetSplit)

test/Microsoft.ML.AutoML.Tests/AutoMLExperimentTests.cs

@@ -354,6 +354,26 @@ public async Task AutoMLExperiment_Taxi_Fare_CV_5_Test()
             result.Metric.Should().BeGreaterThan(0.5);
         }
 
+        [Fact]
+        public async Task AutoMLExperiment_Taxi_Fare_CV_5_SamplingKey_Test()
+        {
+            var context = new MLContext(1);
+            var train = DatasetUtil.GetTaxiFareTrainDataView();
+            var experiment = context.Auto().CreateExperiment();
+            var label = DatasetUtil.TaxiFareLabel;
+            var pipeline = context.Auto().Featurizer(train, excludeColumns: new[] { label })
+                                .Append(context.Auto().Regression(label, useLgbm: false, useSdca: false, useLbfgsPoissonRegression: false));
+
+            experiment.SetDataset(train, 5, "vendor_id")
+                    .SetRegressionMetric(RegressionMetric.RSquared, label)
+                    .SetPipeline(pipeline)
+                    .SetMaxModelToExplore(1);
+
+            var result = await experiment.RunAsync();
+            result.Metric.Should().BeGreaterThan(0.2);
+            result.Metric.Should().BeLessThan(0.5);
+        }
+
         [Fact]
         public void AutoMLExperiment_should_use_seed_from_context_if_provided()
         {