org.apache.commons.statistics.descriptive.IntMin Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.statistics.descriptive;
import java.math.BigInteger;
/**
* Returns the minimum of the available values. Uses {@link Math#min(int, int) Math.min} as an
* underlying function to compute the {@code minimum}.
*
*
* - The result is {@link Integer#MAX_VALUE} if no values are added.
*
*
* This class is designed to work with (though does not require)
* {@linkplain java.util.stream streams}.
*
*
This implementation is not thread safe.
* If multiple threads access an instance of this class concurrently,
* and at least one of the threads invokes the {@link java.util.function.IntConsumer#accept(int) accept} or
* {@link StatisticAccumulator#combine(StatisticResult) combine} method, it must be synchronized externally.
*
*
However, it is safe to use {@link java.util.function.IntConsumer#accept(int) accept}
* and {@link StatisticAccumulator#combine(StatisticResult) combine}
* as {@code accumulator} and {@code combiner} functions of
* {@link java.util.stream.Collector Collector} on a parallel stream,
* because the parallel implementation of {@link java.util.stream.Stream#collect Stream.collect()}
* provides the necessary partitioning, isolation, and merging of results for
* safe and efficient parallel execution.
*
* @since 1.1
* @see Math#min(int, int)
*/
public final class IntMin implements IntStatistic, StatisticAccumulator {
/** Current minimum. */
private int minimum = Integer.MAX_VALUE;
/**
* Create an instance.
*/
private IntMin() {
// No-op
}
/**
* Creates an instance.
*
* The initial result is {@link Integer#MAX_VALUE}.
*
* @return {@code Min} instance.
*/
public static IntMin create() {
return new IntMin();
}
/**
* Returns an instance populated using the input {@code values}.
*
*
When the input is an empty array, the result is
* {@link Integer#MAX_VALUE}.
*
* @param values Values.
* @return {@code Min} instance.
*/
public static IntMin of(int... values) {
return Statistics.add(new IntMin(), values);
}
/**
* Updates the state of the statistic to reflect the addition of {@code value}.
*
* @param value Value.
*/
@Override
public void accept(int value) {
minimum = Math.min(minimum, value);
}
/**
* Gets the minimum of all input values.
*
*
When no values have been added, the result is
* {@link Integer#MAX_VALUE}.
*
* @return minimum of all values.
*/
@Override
public int getAsInt() {
return minimum;
}
@Override
public long getAsLong() {
return minimum;
}
@Override
public double getAsDouble() {
return minimum;
}
@Override
public BigInteger getAsBigInteger() {
return BigInteger.valueOf(minimum);
}
@Override
public IntMin combine(IntMin other) {
accept(other.getAsInt());
return this;
}
}