stream.data.NormalizeVector Maven / Gradle / Ivy

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/**
 * 
 */
package stream.data;

import java.io.Serializable;
import java.util.Set;

import stream.Data;
import stream.Processor;
import stream.learner.LearnerUtils;
import stream.util.KeyFilter;

/**
 * @author chris
 * 
 */
public class NormalizeVector implements Processor {

	String[] keys;

	/**
	 * @see stream.Processor#process(stream.data.Data)
	 */
	@Override
	public Data process(Data input) {

		Double sum = 0.0;
		Set ks = KeyFilter.select(input, keys);

		for (String key : ks) {
			if (LearnerUtils.isAnnotation(key))
				continue;

			Serializable value = input.get(key);
			if (value instanceof Number) {
				double d = ((Number) value).doubleValue();
				sum += (d * d);
			}
		}

		if (sum > 0.0) {
			sum = Math.sqrt(sum);
			for (String key : ks) {
				if (LearnerUtils.isAnnotation(key))
					continue;

				Serializable value = input.get(key);
				if (value instanceof Number) {
					input.put(key, ((Number) value).doubleValue() / sum);
				}
			}
		}

		return input;
	}

	/**
	 * @return the keys
	 */
	public String[] getKeys() {
		return keys;
	}

	/**
	 * @param keys
	 *            the keys to set
	 */
	public void setKeys(String[] keys) {
		this.keys = keys;
	}
}