From c653c819d2e4593e4159f39e9172ca8c4d216ee8 Mon Sep 17 00:00:00 2001
From: Ivan Matantsev <ivmatan@microsoft.com>
Date: Fri, 1 Jun 2018 09:59:23 -0700
Subject: [PATCH 1/3] add append function to pipeline

---
 src/Microsoft.ML/LearningPipeline.cs            | 14 ++++++++++++--
 .../Microsoft.ML.Tests/LearningPipelineTests.cs | 17 +++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/Microsoft.ML/LearningPipeline.cs b/src/Microsoft.ML/LearningPipeline.cs
index 02a13b702a..352a4feeef 100644
--- a/src/Microsoft.ML/LearningPipeline.cs
+++ b/src/Microsoft.ML/LearningPipeline.cs
@@ -66,7 +66,7 @@ public LearningPipeline()
         /// </summary>
         /// <param name="seed">Specify seed for random generator</param>
         /// <param name="conc">Specify concurrency factor (default value - autoselection)</param>
-        internal LearningPipeline(int? seed=null, int conc=0)
+        internal LearningPipeline(int? seed = null, int conc = 0)
         {
             _seed = seed;
             _conc = conc;
@@ -109,6 +109,16 @@ internal LearningPipeline(int? seed=null, int conc=0)
         /// <param name="item">Any ML component (data loader, transform or trainer) defined as <see cref="ILearningPipelineItem"/>.</param>
         public void Add(ILearningPipelineItem item) => Items.Add(item);
 
+        /// <summary>
+        /// Add a data loader, transform or trainer into the pipeline.
+        /// </summary>
+        /// <param name="item">Any ML component (data loader, transform or trainer) defined as <see cref="ILearningPipelineItem"/>.</param>
+        /// <returns>Pipeline with added item</returns>
+        public LearningPipeline Append(ILearningPipelineItem item)
+        {
+            Items.Add(item);
+            return this;
+        }
         /// <summary>
         /// Remove all the loaders/transforms/trainers from the pipeline.
         /// </summary>
@@ -152,7 +162,7 @@ public PredictionModel<TInput, TOutput> Train<TInput, TOutput>()
             where TInput : class
             where TOutput : class, new()
         {
-            using (var environment = new TlcEnvironment(seed:_seed, conc:_conc))
+            using (var environment = new TlcEnvironment(seed: _seed, conc: _conc))
             {
                 Experiment experiment = environment.CreateExperiment();
                 ILearningPipelineStep step = null;
diff --git a/test/Microsoft.ML.Tests/LearningPipelineTests.cs b/test/Microsoft.ML.Tests/LearningPipelineTests.cs
index 63a8db17ee..165b8d8fd2 100644
--- a/test/Microsoft.ML.Tests/LearningPipelineTests.cs
+++ b/test/Microsoft.ML.Tests/LearningPipelineTests.cs
@@ -167,5 +167,22 @@ public void NullableBooleanLabelPipeline()
             pipeline.Add(new FastForestBinaryClassifier());
             var model = pipeline.Train<Data, Prediction>();
         }
+
+        [Fact]
+        public void AppendPipeline()
+        {
+            var pipeline = new LearningPipeline();
+            pipeline.Append(new CategoricalOneHotVectorizer("String1", "String2"))
+                .Append(new ColumnConcatenator(outputColumn: "Features", "String1", "String2", "Number1", "Number2"))
+                .Append(new StochasticDualCoordinateAscentRegressor());
+            Assert.NotNull(pipeline);
+            Assert.Equal(3, pipeline.Count);
+
+            pipeline.Remove(pipeline.ElementAt(2));
+            Assert.Equal(2, pipeline.Count);
+
+            pipeline.Append(new StochasticDualCoordinateAscentRegressor());
+            Assert.Equal(3, pipeline.Count);
+        }
     }
 }

From a6bb2ffe99190e2fb93b75d8e57fd9e6a218ab43 Mon Sep 17 00:00:00 2001
From: Ivan Matantsev <ivmatan@microsoft.com>
Date: Mon, 4 Jun 2018 13:03:20 -0700
Subject: [PATCH 2/3] address Tom comment

---
 src/Microsoft.ML/LearningPipeline.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Microsoft.ML/LearningPipeline.cs b/src/Microsoft.ML/LearningPipeline.cs
index 352a4feeef..0637c5e65e 100644
--- a/src/Microsoft.ML/LearningPipeline.cs
+++ b/src/Microsoft.ML/LearningPipeline.cs
@@ -116,7 +116,7 @@ internal LearningPipeline(int? seed = null, int conc = 0)
         /// <returns>Pipeline with added item</returns>
         public LearningPipeline Append(ILearningPipelineItem item)
         {
-            Items.Add(item);
+            Add(item);
             return this;
         }
         /// <summary>

From bda3c5c0204c4fe7ea6398bf3e1ea0ee6a2cf215 Mon Sep 17 00:00:00 2001
From: Ivan Matantsev <ivmatan@microsoft.com>
Date: Wed, 6 Jun 2018 09:15:24 -0700
Subject: [PATCH 3/3] fix failing test, merge master

---
 .../Scenarios/IrisPlantClassificationTests.cs                   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/Microsoft.ML.Tests/Scenarios/IrisPlantClassificationTests.cs b/test/Microsoft.ML.Tests/Scenarios/IrisPlantClassificationTests.cs
index 5dcbf3a588..6612dfea69 100644
--- a/test/Microsoft.ML.Tests/Scenarios/IrisPlantClassificationTests.cs
+++ b/test/Microsoft.ML.Tests/Scenarios/IrisPlantClassificationTests.cs
@@ -18,7 +18,7 @@ public void TrainAndPredictIrisModelTest()
         {
             string dataPath = GetDataPath("iris.txt");
 
-            var pipeline = new LearningPipeline();
+            var pipeline = new LearningPipeline(seed:1, conc:1);
 
             pipeline.Add(new TextLoader(dataPath).CreateFrom<IrisData>(useHeader: false));
             pipeline.Add(new ColumnConcatenator(outputColumn: "Features",