/*
* 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 com.facebook.presto.operator.aggregation;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.type.StandardTypes;
import com.google.common.collect.ImmutableList;
import org.apache.commons.math3.stat.correlation.PearsonsCorrelation;
import java.util.List;
import static com.facebook.presto.block.BlockAssertions.createSequenceBlockOfReal;
import static com.facebook.presto.operator.aggregation.AggregationTestUtils.constructDoublePrimitiveArray;
public class TestRealCorrelationAggregation
extends AbstractTestAggregationFunction
{
@Override
public Block[] getSequenceBlocks(int start, int length)
{
return new Block[] {createSequenceBlockOfReal(start, start + length), createSequenceBlockOfReal(start + 2, start + 2 + length)};
}
@Override
protected String getFunctionName()
{
return "corr";
}
@Override
protected List<String> getFunctionParameterTypes()
{
return ImmutableList.of(StandardTypes.REAL, StandardTypes.REAL);
}
@Override
public Object getExpectedValue(int start, int length)
{
if (length <= 1) {
return null;
}
PearsonsCorrelation corr = new PearsonsCorrelation();
return (float) corr.correlation(constructDoublePrimitiveArray(start + 2, length), constructDoublePrimitiveArray(start, length));
}
}