AdvancedExperimentSettings sample nits (dotnet#265)

Author: daholste

src/Samples/AdvancedExperimentSettings.cs

@@ -38,11 +38,15 @@ public static void Run()
             experimentSettings.ProgressHandler = new ProgressHandler();
 
             // STEP 3: Using a different optimizing metric instead of RSquared and use only LightGbm
-            Console.WriteLine($"Starting an experiment with MeanSquaredError optimizing metric and using LightGbm trainer only");
             experimentSettings.OptimizingMetric = RegressionMetric.MeanSquaredError;
             experimentSettings.Trainers.Clear();
             experimentSettings.Trainers.Add(RegressionTrainer.LightGbm);
 
+            // STEP 4: Start AutoML experiment
+            Console.WriteLine($"Starting an experiment with MeanSquaredError optimizing metric and using LightGbm trainer only\r\n");
+            RegressionExperiment autoExperiment = mlContext.Auto().CreateRegressionExperiment(experimentSettings);
+            autoExperiment.Execute(trainDataView, LabelColumn);
+
             Console.WriteLine("Press any key to continue...");
             Console.ReadKey();
         }

src/Samples/ObserveProgress.cs

@@ -47,13 +47,19 @@ public static void Run()
     class ProgressHandler : IProgress<RunResult<RegressionMetrics>>
     {
         int iterationIndex;
+        private bool _initialized = false;
+
         public ProgressHandler()
         {
-            ConsolePrinter.PrintRegressionMetricsHeader();
         }
 
         public void Report(RunResult<RegressionMetrics> iterationResult)
         {
+            if (!_initialized)
+            {
+                ConsolePrinter.PrintRegressionMetricsHeader();
+                _initialized = true;
+            }
             iterationIndex++;
             ConsolePrinter.PrintRegressionMetrics(iterationIndex, iterationResult.TrainerName, iterationResult.ValidationMetrics);
         }