io.prestosql.tests.statistics.MetricComparisonStrategies Maven / Gradle / Ivy
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* 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
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*/
package io.prestosql.tests.statistics;
import static com.google.common.base.Preconditions.checkArgument;
public final class MetricComparisonStrategies
{
private MetricComparisonStrategies() {}
public static MetricComparisonStrategy noError()
{
return absoluteError(0);
}
public static MetricComparisonStrategy absoluteError(double error)
{
return absoluteError(-error, error);
}
public static MetricComparisonStrategy absoluteError(double minError, double maxError)
{
checkArgument(minError <= maxError, "minError '%s' has to be lower or equal than maxError '%s'", minError, maxError);
return (actual, estimate) -> {
double minEstimateValue = actual + minError;
double maxEstimateValue = actual + maxError;
return estimate >= minEstimateValue && estimate <= maxEstimateValue;
};
}
public static MetricComparisonStrategy defaultTolerance()
{
return relativeError(.1);
}
public static MetricComparisonStrategy relativeError(double error)
{
return relativeError(-error, error);
}
public static MetricComparisonStrategy relativeError(double minError, double maxError)
{
checkArgument(minError <= maxError, "minError '%s' has to be lower or equal than maxError '%s'", minError, maxError);
return (actual, estimate) -> {
double minEstimateValue = actual * (minError + 1);
double maxEstimateValue = actual * (maxError + 1);
return estimate >= minEstimateValue && estimate <= maxEstimateValue;
};
}
}