protected void TrainReclassificationPredictor(RoleMappedData trainer_input, IPredictor predictor,
ISubComponent <ITrainer> argsPred)
{
if (argsPred == null)
{
_reclassPredictor = null;
return;
}
using (var ch = Host.Start("Training reclassification predictor"))
{
ch.Info("Training reclassification learner");
Contracts.CheckUserArg(argsPred.IsGood(), "reclassificationPredictor", "Must specify a base learner type");
var trainer = argsPred.CreateInstance(Host);
var args = new PredictTransform.Arguments
{
featureColumn = trainer_input.Schema.Feature.Value.Name,
outputColumn = DataViewUtils.GetTempColumnName(trainer_input.Data.Schema)
};
var data = new PredictTransform(Host, args, trainer_input.Data, predictor);
var roles = new[] { RoleMappedSchema.ColumnRole.Feature.Bind(args.outputColumn),
RoleMappedSchema.ColumnRole.Label.Bind(trainer_input.Schema.Label.Value.Name) };
var data_roles = new RoleMappedData(data, roles);
var trainerRoles = trainer as ITrainer <TVectorPredictor>;
if (trainerRoles == null)
{
throw Host.Except("Trainer reclassification cannot be trained.");
}
_reclassPredictor = trainerRoles.Train(data_roles);
}
}
protected override IDataTransform Create(IHostEnvironment env, PredictTransform.Arguments args_, IDataView input, out IDataView sourceCtx, IPredictor overwritePredictor)
{
Contracts.CheckValue(env, "env");
env.CheckValue(args_, "args_");
var args = args_ as Arguments;
env.CheckValue(args, "args");
env.CheckValue(input, "input");
IPredictor predictor;
if (overwritePredictor == null)
{
env.CheckUserArg(!string.IsNullOrWhiteSpace(args.taggedPredictor), "taggedPredictor",
"The input tag is required.");
predictor = TagHelper.GetTaggedPredictor(env, input, args.taggedPredictor);
}
else
{
predictor = overwritePredictor;
}
return(base.Create(env, args, input, out sourceCtx, predictor));
}
