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authorErich Schubert <erich@debian.org>2013-10-29 20:02:37 +0100
committerAndrej Shadura <andrewsh@debian.org>2019-03-09 22:30:37 +0000
commitec7f409f6e795bbcc6f3c005687954e9475c600c (patch)
treefbf36c0ab791c556198b487ca40ae56ae5ab1ee5 /src/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/SquaredEuclideanDistanceFunction.java
parent974d4cf6d54cadc06258039f2cd0515cc34aeac6 (diff)
parent8300861dc4c62c5567a4e654976072f854217544 (diff)
Import Debian changes 0.6.0~beta2-1
elki (0.6.0~beta2-1) unstable; urgency=low * New upstream beta release. * 3DPC extension is not yet included.
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diff --git a/src/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/SquaredEuclideanDistanceFunction.java b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/SquaredEuclideanDistanceFunction.java
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+package de.lmu.ifi.dbs.elki.distance.distancefunction.minkowski;
+
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2013
+ Ludwig-Maximilians-Universität München
+ Lehr- und Forschungseinheit für Datenbanksysteme
+ ELKI Development Team
+
+ This program 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.
+
+ This program 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/>.
+ */
+
+import de.lmu.ifi.dbs.elki.data.NumberVector;
+import de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable;
+import de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialDoubleDistanceNorm;
+import de.lmu.ifi.dbs.elki.utilities.Alias;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+
+/**
+ * Provides the squared Euclidean distance for FeatureVectors. This results in
+ * the same rankings, but saves computing the square root as often.
+ *
+ * @author Arthur Zimek
+ */
+@Alias({ "squaredeuclidean", "de.lmu.ifi.dbs.elki.distance.distancefunction.SquaredEuclideanDistanceFunction" })
+public class SquaredEuclideanDistanceFunction extends AbstractSpatialDoubleDistanceNorm {
+ /**
+ * Static instance. Use this!
+ */
+ public static final SquaredEuclideanDistanceFunction STATIC = new SquaredEuclideanDistanceFunction();
+
+ /**
+ * Provides a Euclidean distance function that can compute the Euclidean
+ * distance (that is a DoubleDistance) for FeatureVectors.
+ *
+ * @deprecated Use static instance!
+ */
+ @Deprecated
+ public SquaredEuclideanDistanceFunction() {
+ super();
+ }
+
+ @Override
+ public double doubleDistance(NumberVector<?> v1, NumberVector<?> v2) {
+ final int dim = dimensionality(v1, v2);
+ double agg = 0.;
+ for (int d = 0; d < dim; d++) {
+ final double delta = v1.doubleValue(d) - v2.doubleValue(d);
+ agg += delta * delta;
+ }
+ return agg;
+ }
+
+ @Override
+ public double doubleNorm(NumberVector<?> v) {
+ final int dim = v.getDimensionality();
+ double agg = 0.;
+ for (int d = 0; d < dim; d++) {
+ final double val = v.doubleValue(d);
+ agg += val * val;
+ }
+ return agg;
+ }
+
+ protected double doubleMinDistObject(NumberVector<?> v, SpatialComparable mbr) {
+ final int dim = dimensionality(mbr, v);
+ double agg = 0.;
+ for (int d = 0; d < dim; d++) {
+ final double value = v.doubleValue(d), min = mbr.getMin(d);
+ final double diff;
+ if (value < min) {
+ diff = min - value;
+ } else {
+ final double max = mbr.getMax(d);
+ if (value > max) {
+ diff = value - max;
+ } else {
+ continue;
+ }
+ }
+ agg += diff * diff;
+ }
+ return agg;
+ }
+
+ @Override
+ public double doubleMinDist(SpatialComparable mbr1, SpatialComparable mbr2) {
+ // Some optimizations for simpler cases.
+ if (mbr1 instanceof NumberVector) {
+ if (mbr2 instanceof NumberVector) {
+ return doubleDistance((NumberVector<?>) mbr1, (NumberVector<?>) mbr2);
+ } else {
+ return doubleMinDistObject((NumberVector<?>) mbr1, mbr2);
+ }
+ } else if (mbr2 instanceof NumberVector) {
+ return doubleMinDistObject((NumberVector<?>) mbr2, mbr1);
+ }
+ final int dim = dimensionality(mbr1, mbr2);
+
+ double agg = 0.;
+ for (int d = 0; d < dim; d++) {
+ final double diff;
+ final double d1 = mbr2.getMin(d) - mbr1.getMax(d);
+ if (d1 > 0.) {
+ diff = d1;
+ } else {
+ final double d2 = mbr1.getMin(d) - mbr2.getMax(d);
+ if (d2 > 0.) {
+ diff = d2;
+ } else {
+ continue;
+ }
+ }
+ agg += diff * diff;
+ }
+ return agg;
+ }
+
+ @Override
+ public boolean isMetric() {
+ return false;
+ }
+
+ @Override
+ public String toString() {
+ return "SquaredEuclideanDistance";
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (obj == null) {
+ return false;
+ }
+ if (obj == this) {
+ return true;
+ }
+ return this.getClass().equals(obj.getClass());
+ }
+
+ /**
+ * Parameterization class.
+ *
+ * @author Erich Schubert
+ *
+ * @apiviz.exclude
+ */
+ public static class Parameterizer extends AbstractParameterizer {
+ @Override
+ protected SquaredEuclideanDistanceFunction makeInstance() {
+ return SquaredEuclideanDistanceFunction.STATIC;
+ }
+ }
+}