stream.statistics.Average Maven / Gradle / Ivy
/*
* streams library
*
* Copyright (C) 2011-2012 by Christian Bockermann, Hendrik Blom
*
* streams is a library, API and runtime environment for processing high
* volume data streams. It is composed of three submodules "stream-api",
* "stream-core" and "stream-runtime".
*
* The streams library (and its submodules) is free software: you can
* redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* The stream.ai library (and its submodules) is distributed in the hope
* that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package stream.statistics;
import stream.annotations.Description;
import stream.data.Data;
/**
* @author chris
*
*/
@Description(group = "Data Stream.Processing.Statistics", text = "Continuously determines the average value of numeric attributes")
public class Average extends Sum {
Double count = 0.0d;
/**
* @see stream.statistics.Sum#updateStatistics(stream.data.Data)
*/
@Override
public void updateStatistics(Data item) {
if (keys == null)
return;
count += 1.0d;
for (String key : keys) {
Double val = null;
try {
val = new Double(item.get(key) + "");
} catch (Exception e) {
val = null;
}
if (val != null) {
statistics.add(key, val);
if (prefix != null)
item.put(prefix + key, statistics.get(key) / count);
else
item.put(key, statistics.get(key) / count);
}
}
}
}