/**
* 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.mahout.cf.taste.impl.common;
/**
* <p>
* A simple class that represents a fixed value of an average, count and standard deviation. This is useful
* when an API needs to return {@link RunningAverageAndStdDev} but is not in a position to accept
* updates to it.
* </p>
*/
public final class FixedRunningAverageAndStdDev extends FixedRunningAverage implements RunningAverageAndStdDev {
private final double stdDev;
public FixedRunningAverageAndStdDev(double average, double stdDev, int count) {
super(average, count);
this.stdDev = stdDev;
}
@Override
public RunningAverageAndStdDev inverse() {
return new InvertedRunningAverageAndStdDev(this);
}
@Override
public synchronized String toString() {
return super.toString() + ',' + stdDev;
}
@Override
public double getStandardDeviation() {
return stdDev;
}
}