Updates to OVA:

- Renamed OVA to OneVersusAllTrainer
- Renames to abbreviated arguments
- Updates to comments and documentation

Related to #2619

Author: singlis

src/Microsoft.ML.EntryPoints/ModelOperations.cs

@@ -155,7 +155,7 @@ public static PredictorModelOutput CombineOvaModels(IHostEnvironment env, Combin
                 return new PredictorModelOutput
                 {
                     PredictorModel = new PredictorModelImpl(env, data, input.TrainingData,
-                    OvaModelParameters.Create(host, input.UseProbabilities,
+                    OneVersusAllModelParameters.Create(host, input.UseProbabilities,
                             input.ModelArray.Select(p => p.Predictor as IPredictorProducing<float>).ToArray()))
                 };
             }

src/Microsoft.ML.LightGBM.StaticPipe/LightGbmStaticExtensions.cs

@@ -305,7 +305,7 @@ public static (Vector<float> score, Key<uint, TVal> predictedLabel)
             int? minDataPerLeaf = null,
             double? learningRate = null,
             int numBoostRound = Options.Defaults.NumBoostRound,
-            Action<OvaModelParameters> onFit = null)
+            Action<OneVersusAllModelParameters> onFit = null)
         {
             CheckUserValues(label, features, weights, numLeaves, minDataPerLeaf, learningRate, numBoostRound, onFit);
 
@@ -343,7 +343,7 @@ public static (Vector<float> score, Key<uint, TVal> predictedLabel)
             Vector<float> features,
             Scalar<float> weights,
             Options options,
-            Action<OvaModelParameters> onFit = null)
+            Action<OneVersusAllModelParameters> onFit = null)
         {
             CheckUserValues(label, features, weights, options, onFit);
 

src/Microsoft.ML.LightGBM/LightGbmMulticlassTrainer.cs

@@ -21,7 +21,7 @@ namespace Microsoft.ML.LightGBM
 {
 
     /// <include file='doc.xml' path='doc/members/member[@name="LightGBM"]/*' />
-    public sealed class LightGbmMulticlassTrainer : LightGbmTrainerBase<VBuffer<float>, MulticlassPredictionTransformer<OvaModelParameters>, OvaModelParameters>
+    public sealed class LightGbmMulticlassTrainer : LightGbmTrainerBase<VBuffer<float>, MulticlassPredictionTransformer<OneVersusAllModelParameters>, OneVersusAllModelParameters>
     {
         internal const string Summary = "LightGBM Multi Class Classifier";
         internal const string LoadNameValue = "LightGBMMulticlass";
@@ -80,7 +80,7 @@ private LightGbmBinaryModelParameters CreateBinaryPredictor(int classID, string
             return new LightGbmBinaryModelParameters(Host, GetBinaryEnsemble(classID), FeatureCount, innerArgs);
         }
 
-        private protected override OvaModelParameters CreatePredictor()
+        private protected override OneVersusAllModelParameters CreatePredictor()
         {
             Host.Check(TrainedEnsemble != null, "The predictor cannot be created before training is complete.");
 
@@ -97,9 +97,9 @@ private protected override OvaModelParameters CreatePredictor()
             }
             string obj = (string)GetGbmParameters()["objective"];
             if (obj == "multiclass")
-                return OvaModelParameters.Create(Host, OvaModelParameters.OutputFormula.Softmax, predictors);
+                return OneVersusAllModelParameters.Create(Host, OneVersusAllModelParameters.OutputFormula.Softmax, predictors);
             else
-                return OvaModelParameters.Create(Host, predictors);
+                return OneVersusAllModelParameters.Create(Host, predictors);
         }
 
         private protected override void CheckDataValid(IChannel ch, RoleMappedData data)
@@ -218,14 +218,14 @@ private protected override SchemaShape.Column[] GetOutputColumnsCore(SchemaShape
             };
         }
 
-        private protected override MulticlassPredictionTransformer<OvaModelParameters> MakeTransformer(OvaModelParameters model, DataViewSchema trainSchema)
-            => new MulticlassPredictionTransformer<OvaModelParameters>(Host, model, trainSchema, FeatureColumn.Name, LabelColumn.Name);
+        private protected override MulticlassPredictionTransformer<OneVersusAllModelParameters> MakeTransformer(OneVersusAllModelParameters model, DataViewSchema trainSchema)
+            => new MulticlassPredictionTransformer<OneVersusAllModelParameters>(Host, model, trainSchema, FeatureColumn.Name, LabelColumn.Name);
 
         /// <summary>
         /// Trains a <see cref="LightGbmMulticlassTrainer"/> using both training and validation data, returns
-        /// a <see cref="MulticlassPredictionTransformer{OvaModelParameters}"/>.
+        /// a <see cref="MulticlassPredictionTransformer{OneVsAllModelParameters}"/>.
         /// </summary>
-        public MulticlassPredictionTransformer<OvaModelParameters> Fit(IDataView trainData, IDataView validationData)
+        public MulticlassPredictionTransformer<OneVersusAllModelParameters> Fit(IDataView trainData, IDataView validationData)
             => TrainTransformer(trainData, validationData);
     }
 

src/Microsoft.ML.StandardLearners/Standard/MultiClass/MetaMulticlassTrainer.cs

@@ -20,7 +20,7 @@ public abstract class MetaMulticlassTrainer<TTransformer, TModel> : ITrainerEsti
         where TTransformer : ISingleFeaturePredictionTransformer<TModel>
         where TModel : class
     {
-        public abstract class OptionsBase
+        internal abstract class OptionsBase
         {
             [Argument(ArgumentType.Multiple, HelpText = "Base predictor", ShortName = "p", SortOrder = 4, SignatureType = typeof(SignatureBinaryClassifierTrainer))]
             [TGUI(Label = "Predictor Type", Description = "Type of underlying binary predictor")]
@@ -39,7 +39,7 @@ public abstract class OptionsBase
         /// <summary>
         /// The label column that the trainer expects.
         /// </summary>
-        public readonly SchemaShape.Column LabelColumn;
+        private protected readonly SchemaShape.Column LabelColumn;
 
         private protected readonly OptionsBase Args;
         private protected readonly IHost Host;