/*
* Copyright (c) 2007-2013 Concurrent, Inc. All Rights Reserved.
*
* Project and contact information: http://www.cascading.org/
*
* This file is part of the Cascading project.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cascading.pattern.model.generalregression;
import cascading.flow.FlowProcess;
import cascading.operation.FunctionCall;
import cascading.pattern.model.generalregression.expression.ExpressionEvaluator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Class PredictionRegressionFunction will return a single prediction
* as determined by the {@link RegressionTable}s added to the {@link GeneralRegressionSpec}.
*/
public class PredictionRegressionFunction extends BaseRegressionFunction
{
private static final Logger LOG = LoggerFactory.getLogger( PredictionRegressionFunction.class );
public PredictionRegressionFunction( GeneralRegressionSpec param )
{
super( param );
if( getSpec().getRegressionTables().size() != 1 )
throw new IllegalArgumentException( "regression function only supports a single table, got: " + getSpec().getRegressionTables().size() );
}
@Override
public void operate( FlowProcess flowProcess, FunctionCall<Context<BaseRegressionFunction.ExpressionContext>> functionCall )
{
ExpressionEvaluator evaluator = functionCall.getContext().payload.expressions[ 0 ];
LinkFunction linkFunction = getSpec().linkFunction;
double result = evaluator.calculate( functionCall.getArguments() );
double linkResult = linkFunction.calculate( result );
LOG.debug( "result: {}", linkResult );
functionCall.getOutputCollector().add( functionCall.getContext().result( linkResult ) );
}
}