hivemall.mix.store.PartialAverage 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 hivemall.mix.store;
import javax.annotation.Nonnegative;
import javax.annotation.concurrent.GuardedBy;
public final class PartialAverage extends PartialResult {
@GuardedBy("lock()")
private double scaledSumWeights;
@GuardedBy("lock()")
private int totalUpdates;
public PartialAverage() {
super();
this.scaledSumWeights = 0.d;
this.totalUpdates = 0;
}
@Override
public float getCovariance(float scale) {
return 1.f;
}
@Override
public void add(float localWeight, float covar, @Nonnegative int deltaUpdates, float scale) {
assert (deltaUpdates > 0) : deltaUpdates;
addWeight(localWeight, deltaUpdates, scale);
incrClock(deltaUpdates);
}
private void addWeight(float localWeight, int deltaUpdates, float scale) {
assert (deltaUpdates > 0) : deltaUpdates;
scaledSumWeights += ((localWeight / scale) * deltaUpdates);
totalUpdates += deltaUpdates; // note deltaUpdates is in range (0,127]
assert (totalUpdates > 0) : totalUpdates;
}
@Override
public void subtract(float localWeight, float covar, @Nonnegative int deltaUpdates, float scale) {
assert (deltaUpdates > 0) : deltaUpdates;
scaledSumWeights -= ((localWeight / scale) * deltaUpdates);
totalUpdates -= deltaUpdates; // note deltaUpdates is in range (0,127]
assert (totalUpdates > 0) : totalUpdates;
}
@Override
public float getWeight(float scale) {
return (float) (scaledSumWeights / totalUpdates) * scale;
}
}