private static IColumn KeyValueMetadataFromMetadata <T>(ISchema schema, int col, string metadataName)
{
Contracts.AssertValue(schema);
Contracts.Assert(0 <= col && col < schema.ColumnCount);
var type = schema.GetMetadataTypeOrNull(metadataName, col);
Contracts.AssertValue(type);
Contracts.Assert(type.RawType == typeof(T));
ValueGetter <T> getter = (ref T val) => schema.GetMetadata(metadataName, col, ref val);
return(RowColumnUtils.GetColumn(MetadataUtils.Kinds.KeyValues, type, getter));
}
private BindingsImpl(ISchema input, ISchemaBoundRowMapper mapper, string suffix, string scoreColumnKind,
bool user, int scoreColIndex, ColumnType predColType)
: base(input, mapper, suffix, user, DefaultColumnNames.PredictedLabel)
{
Contracts.AssertNonEmpty(scoreColumnKind);
Contracts.Assert(DerivedColumnCount == 1);
ScoreColumnIndex = scoreColIndex;
ScoreColumnKind = scoreColumnKind;
PredColType = predColType;
_getScoreColumnKind = GetScoreColumnKind;
_getScoreValueKind = GetScoreValueKind;
// REVIEW: This logic is very specific to multiclass, which is deeply
// regrettable, but the class structure as designed and the status of this schema
// bearing object makes pushing the logic into the multiclass scorer almost impossible.
if (predColType.IsKey)
{
ColumnType scoreSlotsType = mapper.Schema.GetMetadataTypeOrNull(MetadataUtils.Kinds.SlotNames, scoreColIndex);
if (scoreSlotsType != null && scoreSlotsType.IsKnownSizeVector &&
scoreSlotsType.VectorSize == predColType.KeyCount)
{
Contracts.Assert(scoreSlotsType.VectorSize > 0);
IColumn col = Utils.MarshalInvoke(KeyValueMetadataFromMetadata <int>,
scoreSlotsType.RawType, mapper.Schema, scoreColIndex, MetadataUtils.Kinds.SlotNames);
_predColMetadata = RowColumnUtils.GetRow(null, col);
}
else
{
scoreSlotsType = mapper.Schema.GetMetadataTypeOrNull(MetadataUtils.Kinds.TrainingLabelValues, scoreColIndex);
if (scoreSlotsType != null && scoreSlotsType.IsKnownSizeVector &&
scoreSlotsType.VectorSize == predColType.KeyCount)
{
Contracts.Assert(scoreSlotsType.VectorSize > 0);
IColumn col = Utils.MarshalInvoke(KeyValueMetadataFromMetadata <int>,
scoreSlotsType.RawType, mapper.Schema, scoreColIndex, MetadataUtils.Kinds.TrainingLabelValues);
_predColMetadata = RowColumnUtils.GetRow(null, col);
}
}
}
}
/// <summary>
/// Returns a row that is a deep in-memory copy of an input row. Note that inactive
/// columns are allowed in this row, and their activity or inactivity will be reflected
/// in the output row. Note that the deep copy includes a copy of the metadata as well.
/// </summary>
/// <param name="row">The input row</param>
/// <returns>A deep in-memory copy of the input row</returns>
public static IRow CloneRow(IRow row)
{
Contracts.CheckValue(row, nameof(row));
return(RowColumnUtils.GetRow(null,
Utils.BuildArray(row.Schema.ColumnCount, c => RowColumnUtils.GetColumn(row, c))));
}