Read and write binary file documentation

docs/code/MlNetCookBook.md

@@ -41,6 +41,7 @@ Please feel free to search this page and use any code that suits your needs.
 - [How do I train using cross-validation?](#how-do-i-train-using-cross-validation)
 - [Can I mix and match static and dynamic pipelines?](#can-i-mix-and-match-static-and-dynamic-pipelines)
 - [How can I define my own transformation of data?](#how-can-i-define-my-own-transformation-of-data)
+- [How can I read and write binary data?](#how-can-i-read-and-write-binary-data)
 
 ### General questions about the samples
 
@@ -1022,3 +1023,46 @@ ITransformer loadedModel;
 using (var fs = File.OpenRead(modelPath))
     loadedModel = newContext.Model.Load(fs);
 ```
+
+## How can I read and write binary data?
+Other than using text files ML.NET will allow you to read and write binary data. 
+
+To write binary data you need some data to be able to save. Specifically you need an instance of an `IDavaView`. Below is a code snippet that uses the iris data as an example.
+
+```csharp
+// Data model for the iris data
+public class IrisData
+{
+    public float Label;
+    public float SepalLength;
+    public float SepalWidth;
+    public float PetalLength;
+    public float PetalWidth;
+}
+
+// An array of iris data points
+var dataArray = new[] {
+    new IrisData{Label=1, PetalLength=1, SepalLength=1, PetalWidth=1, SepalWidth=1},
+    new IrisData{Label=0, PetalLength=2, SepalLength=2, PetalWidth=2, SepalWidth=2}
+};
+
+// Create the ML.NET context.
+var context = new MLContext();
+
+// Create the data view.
+// This method will use the definition of IrisData to understand what columns there are in the 
+// data view.
+var data = context.CreateDataView(dataArray);
+
+// Use a FileStream to create a file. Use the stream and the data view in the "SaveAsBinary" method.
+using(var stream = new FileStream("./iris.idv", FileMode.Create))
+{
+    context.Data.SaveAsBinary(data, stream);
+}
+```
+
+To read a binary file, simply use the `context.Data.ReadFromBinary` method and pass in the path of the binary file to read in.
+
+```csharp
+var data = context.Data.ReadFromBinary("./iris.idv");
+```

docs/samples/Microsoft.ML.Samples/Dynamic/DataOperations/SaveAndReadFromBinary.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.IO;
+using Microsoft.Data.DataView;
+using Microsoft.ML.SamplesUtils;
+
+namespace Microsoft.ML.Samples.Dynamic.DataOperations
+{
+    public class SaveAndLoadFromBinary
+    {
+        public static void Example()
+        {
+            var mlContext = new MLContext();
+
+            // Get a small dataset as an IEnumerable.
+            IEnumerable<DatasetUtils.SampleTemperatureData> enumerableOfData = DatasetUtils.GetSampleTemperatureData(5);
+
+            // Load dataset into an IDataView. 
+            IDataView data = mlContext.Data.LoadFromEnumerable(enumerableOfData);
+
+            // Creating a FileStream object to create a file and use             
+            // the stream to create a binary file.
+            using (var stream = new FileStream("./sample-temp-data.idv", FileMode.Create))
+            {
+                mlContext.Data.SaveAsBinary(data, stream);
+            }
+
+            // Load a binary file by file path.
+            var binaryData = mlContext.Data.LoadFromBinary("./sample-temp-data.idv");
+        }
+    }
+}