Added RankingEvaluatorOptions and removed the truncation limit.

src/Microsoft.ML.Data/Commands/EvaluateCommand.cs

@@ -26,8 +26,7 @@ namespace Microsoft.ML.Data
     /// This class contains information about an overall metric, namely its name and whether it is a vector
     /// metric or not.
     /// </summary>
-    [BestFriend]
-    internal sealed class MetricColumn
+    public sealed class MetricColumn
     {
         /// <summary>
         /// An enum specifying whether the metric should be maximized or minimized while sweeping. 'Info' should be

src/Microsoft.ML.Data/Evaluators/AucAggregator.cs

@@ -10,7 +10,7 @@
 
 namespace Microsoft.ML.Data
 {
-    internal abstract partial class EvaluatorBase<TAgg>
+    public abstract partial class EvaluatorBase<TAgg>
     {
         internal abstract class AucAggregatorBase
         {

src/Microsoft.ML.Data/Evaluators/EvaluatorBase.cs

@@ -15,8 +15,7 @@ namespace Microsoft.ML.Data
     ///  <see cref="GetPerInstanceMetricsCore"/>. Note that the input <see cref="RoleMappedData"/> is assumed to contain all the column
     /// roles needed for evaluation, including the score column.
     /// </summary>
-    [BestFriend]
-    internal abstract partial class EvaluatorBase<TAgg> : IEvaluator
+    public abstract partial class EvaluatorBase<TAgg> : IEvaluator
         where TAgg : EvaluatorBase<TAgg>.AggregatorBase
     {
         protected readonly IHost Host;

src/Microsoft.ML.Data/Evaluators/RankingEvaluator.cs

@@ -26,8 +26,7 @@
 
 namespace Microsoft.ML.Data
 {
-    [BestFriend]
-    internal sealed class RankingEvaluator : EvaluatorBase<RankingEvaluator.Aggregator>
+    public sealed class RankingEvaluator : EvaluatorBase<RankingEvaluator.Aggregator>
     {
         public sealed class Arguments
         {
@@ -271,7 +270,7 @@ public sealed class Aggregator : AggregatorBase
         {
             public sealed class Counters
             {
-                public const int MaxTruncationLevel = 10;
+                public const int MaxTruncationLevel = 100;
 
                 public readonly int TruncationLevel;
                 private readonly List<Double[]> _groupNdcg;