public DataView(IHostEnvironment env, ArrayDataViewBuilder builder, int rowCount)
{
Contracts.AssertValue(env, "env");
_host = env.Register("ArrayDataView");
_host.AssertValue(builder);
_host.Assert(rowCount >= 0);
_host.Assert(builder._names.Count == builder._columns.Count);
_columns = builder._columns.ToArray();
var schemaBuilder = new SchemaBuilder();
for (int i = 0; i < _columns.Length; i++)
{
var meta = new MetadataBuilder();
if (builder._getSlotNames.TryGetValue(builder._names[i], out var slotNamesGetter))
{
meta.AddSlotNames(_columns[i].Type.GetVectorSize(), slotNamesGetter);
}
if (builder._getKeyValues.TryGetValue(builder._names[i], out var keyValueGetter))
{
meta.AddKeyValues(_columns[i].Type.GetKeyCount(), TextType.Instance, keyValueGetter);
}
schemaBuilder.AddColumn(builder._names[i], _columns[i].Type, meta.GetMetadata());
}
_schema = schemaBuilder.GetSchema();
_rowCount = rowCount;
}
/// <summary>
/// This is very similar to <see cref="Create(DataViewType, string, string)"/> but adds one extra metadata field to the only score column.
/// </summary>
/// <param name="scoreType">Output element's type of quantile regressor. Note that a quantile regressor can produce an array of <see cref="PrimitiveDataViewType"/>.</param>
/// <param name="quantiles">Quantiles used in quantile regressor.</param>
/// <returns><see cref="DataViewSchema"/> of quantile regressor's output.</returns>
public static DataViewSchema CreateQuantileRegressionSchema(DataViewType scoreType, double[] quantiles)
{
Contracts.CheckValue(scoreType, nameof(scoreType));
Contracts.CheckValue(scoreType as PrimitiveDataViewType, nameof(scoreType));
Contracts.AssertValue(quantiles);
// Create a schema using standard function. The produced schema will be modified by adding one metadata column.
var partialSchema = Create(new VectorType(scoreType as PrimitiveDataViewType, quantiles.Length), MetadataUtils.Const.ScoreColumnKind.QuantileRegression);
var metadataBuilder = new MetadataBuilder();
// Add the extra metadata.
metadataBuilder.AddSlotNames(quantiles.Length, (ref VBuffer <ReadOnlyMemory <char> > value) =>
{
var bufferEditor = VBufferEditor.Create(ref value, quantiles.Length);
for (int i = 0; i < quantiles.Length; ++i)
{
bufferEditor.Values[i] = string.Format("Quantile-{0}", quantiles[i]).AsMemory();
}
value = bufferEditor.Commit();
});
// Copy default metadata from the partial schema.
metadataBuilder.Add(partialSchema[0].Metadata, (string kind) => true);
// Build a schema consisting of a single column. Comparing with partial schema, the only difference is a metadata field.
var schemaBuilder = new SchemaBuilder();
schemaBuilder.AddColumn(partialSchema[0].Name, partialSchema[0].Type, metadataBuilder.GetMetadata());
return(schemaBuilder.GetSchema());
}
public RowMapper(IHostEnvironment env, BindableMapper parent, RoleMappedSchema schema)
{
Contracts.AssertValue(env);
_env = env;
_env.AssertValue(schema);
_env.AssertValue(parent);
_env.Assert(schema.Feature.HasValue);
_parent = parent;
InputRoleMappedSchema = schema;
var genericMapper = parent.GenericMapper.Bind(_env, schema);
_genericRowMapper = genericMapper as ISchemaBoundRowMapper;
var featureSize = FeatureColumn.Type.GetVectorSize();
if (parent.Stringify)
{
var builder = new SchemaBuilder();
builder.AddColumn(DefaultColumnNames.FeatureContributions, TextType.Instance, null);
_outputSchema = builder.GetSchema();
if (FeatureColumn.HasSlotNames(featureSize))
{
FeatureColumn.Metadata.GetValue(MetadataUtils.Kinds.SlotNames, ref _slotNames);
}
else
{
_slotNames = VBufferUtils.CreateEmpty <ReadOnlyMemory <char> >(featureSize);
}
}
else
{
var metadataBuilder = new MetadataBuilder();
if (InputSchema[FeatureColumn.Index].HasSlotNames(featureSize))
{
metadataBuilder.AddSlotNames(featureSize, (ref VBuffer <ReadOnlyMemory <char> > value) =>
FeatureColumn.Metadata.GetValue(MetadataUtils.Kinds.SlotNames, ref value));
}
var schemaBuilder = new SchemaBuilder();
var featureContributionType = new VectorType(NumberType.R4, FeatureColumn.Type as VectorType);
schemaBuilder.AddColumn(DefaultColumnNames.FeatureContributions, featureContributionType, metadataBuilder.GetMetadata());
_outputSchema = schemaBuilder.GetSchema();
}
_outputGenericSchema = _genericRowMapper.OutputSchema;
OutputSchema = new ZipBinding(new Schema[] { _outputGenericSchema, _outputSchema, }).OutputSchema;
}
