public static CombinedOutput CombineMetrics(IHostEnvironment env, CombineMetricsInput input) { var eval = GetEvaluator(env, input.Kind); var perInst = EvaluateUtils.ConcatenatePerInstanceDataViews(env, eval, true, true, input.PerInstanceMetrics.Select( idv => RoleMappedData.CreateOpt(idv, new[] { RoleMappedSchema.CreatePair(RoleMappedSchema.ColumnRole.Label, input.LabelColumn), RoleMappedSchema.CreatePair(RoleMappedSchema.ColumnRole.Weight, input.WeightColumn.Value), RoleMappedSchema.CreatePair(RoleMappedSchema.ColumnRole.Group, input.GroupColumn.Value) })).ToArray(), out var variableSizeVectorColumnNames); var warnings = input.Warnings != null ? new List <IDataView>(input.Warnings) : new List <IDataView>(); if (variableSizeVectorColumnNames.Length > 0) { var dvBldr = new ArrayDataViewBuilder(env); var warn = $"Detected columns of variable length: {string.Join(", ", variableSizeVectorColumnNames)}." + $" Consider setting collateMetrics- for meaningful per-Folds results."; dvBldr.AddColumn(MetricKinds.ColumnNames.WarningText, TextType.Instance, new DvText(warn)); warnings.Add(dvBldr.GetDataView()); } env.Assert(Utils.Size(perInst) == 1); var overall = eval.GetOverallResults(input.OverallMetrics); overall = EvaluateUtils.CombineFoldMetricsDataViews(env, overall, input.OverallMetrics.Length); IDataView conf = null; if (Utils.Size(input.ConfusionMatrix) > 0) { EvaluateUtils.ReconcileSlotNames <double>(env, input.ConfusionMatrix, MetricKinds.ColumnNames.Count, NumberType.R8); for (int i = 0; i < input.ConfusionMatrix.Length; i++) { var idv = input.ConfusionMatrix[i]; // Find the old Count column and drop it. for (int col = 0; col < idv.Schema.ColumnCount; col++) { if (idv.Schema.IsHidden(col) && idv.Schema.GetColumnName(col).Equals(MetricKinds.ColumnNames.Count)) { input.ConfusionMatrix[i] = new ChooseColumnsByIndexTransform(env, new ChooseColumnsByIndexTransform.Arguments() { Drop = true, Index = new[] { col } }, idv); break; } } } conf = EvaluateUtils.ConcatenateOverallMetrics(env, input.ConfusionMatrix); } var warningsIdv = warnings.Count > 0 ? AppendRowsDataView.Create(env, warnings[0].Schema, warnings.ToArray()) : null; return(new CombinedOutput() { PerInstanceMetrics = perInst[0], OverallMetrics = overall, ConfusionMatrix = conf, Warnings = warningsIdv }); }