/// <summary>
/// Given a predictor, an optional mapper factory, and an optional scorer factory settings,
/// produces a compatible ISchemaBindableMapper.
/// First, it tries to instantiate the bindable mapper using the mapper factory.
/// Next, it tries to instantiate the bindable mapper using the <paramref name="scorerFactorySettings"/>
/// (this will only succeed if there's a registered BindableMapper creation method with load name equal to the one
/// of the scorer).
/// If the above fails, it checks whether the predictor implements <see cref="ISchemaBindableMapper"/>
/// directly.
/// If this also isn't true, it will create a 'matching' standard mapper.
/// </summary>
public static ISchemaBindableMapper GetSchemaBindableMapper(
IHostEnvironment env,
IPredictor predictor,
IComponentFactory<IPredictor, ISchemaBindableMapper> mapperFactory = null,
ICommandLineComponentFactory scorerFactorySettings = null)
{
Contracts.CheckValue(env, nameof(env));
env.CheckValue(predictor, nameof(predictor));
env.CheckValueOrNull(mapperFactory);
env.CheckValueOrNull(scorerFactorySettings);
// if the mapperFactory was supplied, use it
if (mapperFactory != null)
return mapperFactory.CreateComponent(env, predictor);
// See if we can instantiate a mapper using scorer arguments.
if (scorerFactorySettings != null && TryCreateBindableFromScorer(env, predictor, scorerFactorySettings, out var bindable))
return bindable;
// The easy case is that the predictor implements the interface.
bindable = predictor as ISchemaBindableMapper;
if (bindable != null)
return bindable;
// Use one of the standard wrappers.
if (predictor is IValueMapperDist)
return new SchemaBindableBinaryPredictorWrapper(predictor);
return new SchemaBindablePredictorWrapper(predictor);
}
private static bool TryCreateBindableFromScorer(IHostEnvironment env, IPredictor predictor,
ICommandLineComponentFactory scorerSettings, out ISchemaBindableMapper bindable)
{
Contracts.AssertValue(env);
env.AssertValue(predictor);
env.AssertValue(scorerSettings);
// Try to find a mapper factory method with the same loadname as the scorer settings.
return(ComponentCatalog.TryCreateInstance <ISchemaBindableMapper, SignatureBindableMapper>(
env, out bindable, scorerSettings.Name, scorerSettings.GetSettingsString(), predictor));
}
/// <summary>
/// Creates a data scorer from the 'LoadName{settings}' string.
/// </summary>
/// <param name="env">The host environment to use.</param>
/// <param name="settings">The settings string.</param>
/// <param name="data">The data to score.</param>
/// <param name="predictor">The predictor to score.</param>
/// <param name="trainSchema">The training data schema from which the scorer can optionally extract
/// additional information, e.g., label names. If this is <c>null</c>, no information will be
/// extracted.</param>
/// <returns>The scored data.</returns>
public static IDataScorerTransform CreateScorer(this IHostEnvironment env, string settings,
RoleMappedData data, Predictor predictor, RoleMappedSchema trainSchema = null)
{
Contracts.CheckValue(env, nameof(env));
env.CheckValue(data, nameof(data));
env.CheckValue(predictor, nameof(predictor));
env.CheckValueOrNull(trainSchema);
ICommandLineComponentFactory scorerFactorySettings = ParseScorerSettings(settings);
var bindable = ScoreUtils.GetSchemaBindableMapper(env, predictor.Pred, scorerFactorySettings: scorerFactorySettings);
var mapper = bindable.Bind(env, data.Schema);
return(CreateCore <IDataScorerTransform, SignatureDataScorer>(env, settings, data.Data, mapper, trainSchema));
}
/// <summary>
/// Creates a data scorer from the 'LoadName{settings}' string.
/// </summary>
/// <param name="env">The host environment to use.</param>
/// <param name="settings">The settings string.</param>
/// <param name="data">The data to score.</param>
/// <param name="predictor">The predictor to score.</param>
/// <param name="trainSchema">The training data schema from which the scorer can optionally extract
/// additional information, for example, label names. If this is <c>null</c>, no information will be
/// extracted.</param>
/// <returns>The scored data.</returns>
internal static IDataScorerTransform CreateScorer(this IHostEnvironment env, string settings,
RoleMappedData data, IPredictor predictor, RoleMappedSchema trainSchema = null)
{
Contracts.CheckValue(env, nameof(env));
env.CheckValue(data, nameof(data));
env.CheckValue(predictor, nameof(predictor));
env.CheckValueOrNull(trainSchema);
Type factoryType = typeof(IComponentFactory <IDataView, ISchemaBoundMapper, RoleMappedSchema, IDataScorerTransform>);
Type signatureType = typeof(SignatureDataScorer);
ICommandLineComponentFactory scorerFactorySettings = CmdParser.CreateComponentFactory(
factoryType,
signatureType,
settings);
var bindable = ScoreUtils.GetSchemaBindableMapper(env, predictor, scorerFactorySettings: scorerFactorySettings);
var mapper = bindable.Bind(env, data.Schema);
return(CreateCore <IDataScorerTransform>(env, factoryType, signatureType, settings, data.Data, mapper, trainSchema));
}
