Created sample for 'ApplyWordEmbedding' API.

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/Text/ApplyCustomWordEmbedding.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Microsoft.ML.Samples.Dynamic
+{
+    public static class ApplyCustomWordEmbedding
+    {
+        public static void Example()
+        {
+            // Create a new ML context, for ML.NET operations. It can be used for exception tracking and logging, 
+            // as well as the source of randomness.
+            var mlContext = new MLContext();
+
+            // Create an empty data sample list. The 'ApplyWordEmbedding' does not require training data as
+            // the estimator ('WordEmbeddingEstimator') created by 'ApplyWordEmbedding' API is not a trainable estimator.
+            // The empty list is only needed to pass input schema to the pipeline.
+            var emptySamples = new List<TextData>();
+
+            // Convert sample list to an empty IDataView.
+            var emptyDataView = mlContext.Data.LoadFromEnumerable(emptySamples);
+
+            // Write a custom 3-dimensional word embedding model with 4 words.
+            // Each line follows '<word> <float> <float> <float>' pattern.
+            // Lines that do not confirm to the pattern are ignored.
+            var pathToCustomModel = @".\custommodel.txt";
+            using (StreamWriter file = new StreamWriter(pathToCustomModel, false))
+            {
+                file.WriteLine("great 1.0 2.0 3.0");
+                file.WriteLine("product -1.0 -2.0 -3.0");
+                file.WriteLine("like -1 100.0 -100");
+                file.WriteLine("buy 0 0 20");
+            }
+
+            // A pipeline for converting text into a 9-dimension word embedding vector using the custom word embedding model.
+            // The 'ApplyWordEmbedding' computes the minimum, average and maximum values for each token's embedding vector.
+            // Tokens in 'custommodel.txt' model are represented as 3-dimension vector.
+            // Therefore, the output is of 9-dimension [min, avg, max].
+            //
+            // The 'ApplyWordEmbedding' API requires vector of text as input.
+            // The pipeline first normalizes and tokenizes text then applies word embedding transformation.
+            var textPipeline = mlContext.Transforms.Text.NormalizeText("Text")
+                .Append(mlContext.Transforms.Text.TokenizeIntoWords("Tokens", "Text"))
+                .Append(mlContext.Transforms.Text.ApplyWordEmbedding("Features", pathToCustomModel, "Tokens"));
+
+            // Fit to data.
+            var textTransformer = textPipeline.Fit(emptyDataView);
+
+            // Create the prediction engine to get the embedding vector from the input text/string.
+            var predictionEngine = mlContext.Model.CreatePredictionEngine<TextData, TransformedTextData>(textTransformer);
+
+            // Call the prediction API to convert the text into embedding vector.
+            var data = new TextData() { Text = "This is a great product. I would like to buy it again."  };
+            var prediction = predictionEngine.Predict(data);
+
+            // Print the length of the embedding vector.
+            Console.WriteLine($"Number of Features: {prediction.Features.Length}");
+
+            // Print the embedding vector.
+            Console.Write("Features: ");
+            foreach (var f in prediction.Features)
+                Console.Write($"{f:F4} ");
+
+            //  Expected output:
+            //   Number of Features: 9
+            //   Features: -1.0000 0.0000 -100.0000 0.0000 34.0000 -25.6667 1.0000 100.0000 20.0000
+        }
+
+        public class TextData
+        {
+            public string Text { get; set; }
+        }
+
+        public class TransformedTextData : TextData
+        {
+            public float[] Features { get; set; }
+        }
+    }
+}

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/Text/ApplyWordEmbedding.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Microsoft.ML.Samples.Dynamic
+{
+    public static class ApplyWordEmbedding
+    {
+        public static void Example()
+        {
+            // Create a new ML context, for ML.NET operations. It can be used for exception tracking and logging, 
+            // as well as the source of randomness.
+            var mlContext = new MLContext();
+
+            // Create an empty data sample list. The 'ApplyWordEmbedding' does not require training data as
+            // the estimator ('WordEmbeddingEstimator') created by 'ApplyWordEmbedding' API is not a trainable estimator.
+            // The empty list is only needed to pass input schema to the pipeline.
+            var emptySamples = new List<TextData>();
+
+            // Convert sample list to an empty IDataView.
+            var emptyDataView = mlContext.Data.LoadFromEnumerable(emptySamples);
+
+            // A pipeline for converting text into a 150-dimension embedding vector using pretrained 'SentimentSpecificWordEmbedding' model.
+            // The 'ApplyWordEmbedding' computes the minimum, average and maximum values for each token's embedding vector.
+            // Tokens in 'SentimentSpecificWordEmbedding' model are represented as 50-dimension vector.
+            // Therefore, the output is of 150-dimension [min, avg, max].
+            //
+            // The 'ApplyWordEmbedding' API requires vector of text as input.
+            // The pipeline first normalizes and tokenizes text then applies word embedding transformation.
+            var textPipeline = mlContext.Transforms.Text.NormalizeText("Text")
+                .Append(mlContext.Transforms.Text.TokenizeIntoWords("Tokens", "Text"))
+                .Append(mlContext.Transforms.Text.ApplyWordEmbedding("Features", "Tokens", 
+                    Transforms.Text.WordEmbeddingEstimator.PretrainedModelKind.SentimentSpecificWordEmbedding));
+
+            // Fit to data.
+            var textTransformer = textPipeline.Fit(emptyDataView);
+
+            // Create the prediction engine to get the embedding vector from the input text/string.
+            var predictionEngine = mlContext.Model.CreatePredictionEngine<TextData, TransformedTextData>(textTransformer);
+
+            // Call the prediction API to convert the text into embedding vector.
+            var data = new TextData() { Text = "This is a great product. I would like to buy it again."  };
+            var prediction = predictionEngine.Predict(data);
+
+            // Print the length of the embedding vector.
+            Console.WriteLine($"Number of Features: {prediction.Features.Length}");
+
+            // Print the embedding vector.
+            Console.Write("Features: ");
+            foreach (var f in prediction.Features)
+                Console.Write($"{f:F4} ");
+
+            //  Expected output:
+            //   Number of Features: 150
+            //   Features: -1.2489 0.2384 -1.3034 -0.9135 -3.4978 -0.1784 -1.3823 -0.3863 -2.5262 -0.8950 ...
+        }
+
+        public class TextData
+        {
+            public string Text { get; set; }
+        }
+
+        public class TransformedTextData : TextData
+        {
+            public float[] Features { get; set; }
+        }
+    }
+}

src/Microsoft.ML.Transforms/Text/TextCatalog.cs

@@ -125,7 +125,7 @@ public static TextNormalizingEstimator NormalizeText(this TransformsCatalog.Text
         /// <example>
         /// <format type="text/markdown">
         /// <![CDATA[
-        /// [!code-csharp[FeaturizeText](~/../docs/samples/docs/samples/Microsoft.ML.Samples/Dynamic/WordEmbeddingTransform.cs)]
+        /// [!code-csharp[ApplyWordEmbedding](~/../docs/samples/docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/Text/ApplyWordEmbedding.cs)]
         /// ]]>
         /// </format>
         /// </example>
@@ -143,7 +143,7 @@ public static WordEmbeddingEstimator ApplyWordEmbedding(this TransformsCatalog.T
         /// <example>
         /// <format type="text/markdown">
         /// <![CDATA[
-        /// [!code-csharp[FeaturizeText](~/../docs/samples/docs/samples/Microsoft.ML.Samples/Dynamic/WordEmbeddingTransform.cs)]
+        /// [!code-csharp[ApplyWordEmbedding](~/../docs/samples/docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/Text/ApplyCustomWordEmbedding.cs)]
         /// ]]>
         /// </format>
         /// </example>