/*
* Copyright (C) 2008-2015 by Holger Arndt
*
* This file is part of the Universal Java Matrix Package (UJMP).
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership and licensing.
*
* UJMP is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* UJMP 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with UJMP; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
package org.ujmp.core.doublematrix.calculation.general.misc;
import org.ujmp.core.Matrix;
import org.ujmp.core.doublematrix.calculation.AbstractDoubleCalculation;
import org.ujmp.core.util.MathUtil;
import org.ujmp.core.util.VerifyUtil;
public class CosineSimilarity extends AbstractDoubleCalculation {
private static final long serialVersionUID = 9144182368353349242L;
private final long size[];
private final boolean ignoreNaN;
public CosineSimilarity(Matrix matrix, boolean ignoreNaN) {
super(matrix);
this.size = new long[] { matrix.getRowCount(), matrix.getRowCount() };
this.ignoreNaN = ignoreNaN;
}
public double getDouble(long... coordinates) {
Matrix m1 = getSource().selectRows(Ret.LINK, coordinates[ROW]);
Matrix m2 = getSource().selectRows(Ret.LINK, coordinates[COLUMN]);
double aiSum = 0;
double a2Sum = 0;
double b2Sum = 0;
for (long i = 0; i < m1.getColumnCount(); i++) {
double a = m1.getAsDouble(0, i);
double b = m2.getAsDouble(0, i);
if (ignoreNaN) {
if (!MathUtil.isNaNOrInfinite(a) && !MathUtil.isNaNOrInfinite(b)) {
aiSum += a * b;
a2Sum += a * a;
b2Sum += b * b;
}
} else {
aiSum += a * b;
a2Sum += a * a;
b2Sum += b * b;
}
}
return aiSum / (Math.sqrt(a2Sum) * Math.sqrt(b2Sum));
}
public long[] getSize() {
return size;
}
public static double getCosineSimilartiy(Matrix m1, Matrix m2, boolean ignoreNaN) {
VerifyUtil.verifySameSize(m1, m2);
double aiSum = 0;
double a2Sum = 0;
double b2Sum = 0;
for (long[] c : m1.allCoordinates()) {
double a = m1.getAsDouble(c);
double b = m2.getAsDouble(c);
if (ignoreNaN) {
if (!MathUtil.isNaNOrInfinite(a) && !MathUtil.isNaNOrInfinite(b)) {
aiSum += a * b;
a2Sum += a * a;
b2Sum += b * b;
}
} else {
aiSum += a * b;
a2Sum += a * a;
b2Sum += b * b;
}
}
return aiSum / (Math.sqrt(a2Sum) * Math.sqrt(b2Sum));
}
}