org.apache.mahout.math.hadoop.decomposer.EigenVector 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.mahout.math.hadoop.decomposer;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.Vector;
import java.util.regex.Pattern;
/**
* TODO this is a horrible hack. Make a proper writable subclass also.
*/
public class EigenVector extends NamedVector {
private static final Pattern EQUAL_PATTERN = Pattern.compile(" = ");
private static final Pattern PIPE_PATTERN = Pattern.compile("\\|");
public EigenVector(Vector v, double eigenValue, double cosAngleError, int order) {
super(v instanceof DenseVector ? (DenseVector) v : new DenseVector(v),
"e|" + order + "| = |" + eigenValue + "|, err = " + cosAngleError);
}
public double getEigenValue() {
return getEigenValue(getName());
}
public double getCosAngleError() {
return getCosAngleError(getName());
}
public int getIndex() {
return getIndex(getName());
}
public static double getEigenValue(CharSequence name) {
return parseMetaData(name)[1];
}
public static double getCosAngleError(CharSequence name) {
return parseMetaData(name)[2];
}
public static int getIndex(CharSequence name) {
return (int)parseMetaData(name)[0];
}
public static double[] parseMetaData(CharSequence name) {
double[] m = new double[3];
String[] s = EQUAL_PATTERN.split(name);
m[0] = Double.parseDouble(PIPE_PATTERN.split(s[0])[1]);
m[1] = Double.parseDouble(PIPE_PATTERN.split(s[1])[1]);
m[2] = Double.parseDouble(s[2].substring(1));
return m;
}
protected double[] parseMetaData() {
return parseMetaData(getName());
}
}