diff options
author | Andrej Shadura <andrewsh@debian.org> | 2019-03-09 22:30:41 +0000 |
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committer | Andrej Shadura <andrewsh@debian.org> | 2019-03-09 22:30:41 +0000 |
commit | 38212b3127e90751fb39cda34250bc11be62b76c (patch) | |
tree | dc1397346030e9695bd763dddc93b3be527cd643 /elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java | |
parent | 337087b668d3a54f3afee3a9adb597a32e9f7e94 (diff) |
Import Upstream version 0.7.0
Diffstat (limited to 'elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java')
-rw-r--r-- | elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java b/elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java new file mode 100644 index 00000000..88b5edc5 --- /dev/null +++ b/elki/src/main/java/de/lmu/ifi/dbs/elki/distance/distancefunction/minkowski/LPNormDistanceFunction.java @@ -0,0 +1,313 @@ +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) 2015 + 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.data.type.SimpleTypeInformation; +import de.lmu.ifi.dbs.elki.data.type.TypeUtil; +import de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialNorm; +import de.lmu.ifi.dbs.elki.utilities.Alias; +import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer; +import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID; +import de.lmu.ifi.dbs.elki.utilities.optionhandling.constraints.CommonConstraints; +import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization; +import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.DoubleParameter; + +/** + * LP-Norm for {@link NumberVector}s. + * + * @author Arthur Zimek + * + * @apiviz.landmark + */ +@Alias({ "lp", "minkowski", "p", "de.lmu.ifi.dbs.elki.distance.distancefunction.LPNormDistanceFunction" }) +public class LPNormDistanceFunction extends AbstractSpatialNorm { + /** + * p parameter and its inverse. + */ + protected double p, invp; + + /** + * Constructor, internal version. + * + * @param p Parameter p + */ + public LPNormDistanceFunction(double p) { + super(); + this.p = p; + this.invp = 1. / p; + } + + /** + * Compute unscaled distance in a range of dimensions. + * + * @param v1 First object + * @param v2 Second object + * @param start First dimension + * @param end Exclusive last dimension + * @param agg Current aggregate value + * @return Aggregated values. + */ + private final double preDistance(NumberVector v1, NumberVector v2, final int start, final int end, double agg) { + for(int d = start; d < end; d++) { + final double xd = v1.doubleValue(d), yd = v2.doubleValue(d); + final double delta = (xd >= yd) ? xd - yd : yd - xd; + agg += Math.pow(delta, p); + } + return agg; + } + + /** + * Compute unscaled distance in a range of dimensions. + * + * @param v First vector + * @param mbr Second MBR + * @param start First dimension + * @param end Exclusive last dimension + * @param agg Current aggregate value + * @return Aggregated values. + */ + private final double preDistanceVM(NumberVector v, SpatialComparable mbr, final int start, final int end, double agg) { + for(int d = start; d < end; d++) { + final double value = v.doubleValue(d), min = mbr.getMin(d); + double delta = min - value; + if(delta < 0.) { + delta = value - mbr.getMax(d); + } + if(delta > 0.) { + agg += Math.pow(delta, p); + } + } + return agg; + } + + /** + * Compute unscaled distance in a range of dimensions. + * + * @param mbr1 First MBR + * @param mbr2 Second MBR + * @param start First dimension + * @param end Exclusive last dimension + * @param agg Current aggregate value + * @return Aggregated values. + */ + private final double preDistanceMBR(SpatialComparable mbr1, SpatialComparable mbr2, final int start, final int end, double agg) { + for(int d = start; d < end; d++) { + double delta = mbr2.getMin(d) - mbr1.getMax(d); + if(delta < 0.) { + delta = mbr1.getMin(d) - mbr2.getMax(d); + } + if(delta > 0.) { + agg += Math.pow(delta, p); + } + } + return agg; + } + + /** + * Compute unscaled norm in a range of dimensions. + * + * @param v Data object + * @param start First dimension + * @param end Exclusive last dimension + * @param agg Current aggregate value + * @return Aggregated values. + */ + private final double preNorm(NumberVector v, final int start, final int end, double agg) { + for(int d = start; d < end; d++) { + final double xd = v.doubleValue(d); + final double delta = xd >= 0. ? xd : -xd; + agg += Math.pow(delta, p); + } + return agg; + } + + /** + * Compute unscaled norm in a range of dimensions. + * + * @param mbr Data object + * @param start First dimension + * @param end Exclusive last dimension + * @param agg Current aggregate value + * @return Aggregated values. + */ + private final double preNormMBR(SpatialComparable mbr, final int start, final int end, double agg) { + for(int d = start; d < end; d++) { + double delta = mbr.getMin(d); + if(delta < 0.) { + delta = -mbr.getMax(d); + } + if(delta > 0.) { + agg += Math.pow(delta, p); + } + } + return agg; + } + + @Override + public double distance(NumberVector v1, NumberVector v2) { + final int dim1 = v1.getDimensionality(), dim2 = v2.getDimensionality(); + final int mindim = (dim1 < dim2) ? dim1 : dim2; + double agg = preDistance(v1, v2, 0, mindim, 0.); + if(dim1 > mindim) { + agg = preNorm(v1, mindim, dim1, agg); + } + else if(dim2 > mindim) { + agg = preNorm(v2, mindim, dim2, agg); + } + return Math.pow(agg, invp); + } + + @Override + public double norm(NumberVector v) { + return Math.pow(preNorm(v, 0, v.getDimensionality(), 0.), invp); + } + + @Override + public double minDist(SpatialComparable mbr1, SpatialComparable mbr2) { + final int dim1 = mbr1.getDimensionality(), dim2 = mbr2.getDimensionality(); + final int mindim = (dim1 < dim2) ? dim1 : dim2; + + final NumberVector v1 = (mbr1 instanceof NumberVector) ? (NumberVector) mbr1 : null; + final NumberVector v2 = (mbr2 instanceof NumberVector) ? (NumberVector) mbr2 : null; + + double agg = 0.; + if(v1 != null) { + if(v2 != null) { + agg = preDistance(v1, v2, 0, mindim, agg); + } + else { + agg = preDistanceVM(v1, mbr2, 0, mindim, agg); + } + } + else { + if(v2 != null) { + agg = preDistanceVM(v2, mbr1, 0, mindim, agg); + } + else { + agg = preDistanceMBR(mbr1, mbr2, 0, mindim, agg); + } + } + // first object has more dimensions. + if(dim1 > mindim) { + if(v1 != null) { + agg = preNorm(v1, mindim, dim1, agg); + } + else { + agg = preNormMBR(v1, mindim, dim1, agg); + } + } + // second object has more dimensions. + if(dim2 > mindim) { + if(v2 != null) { + agg = preNorm(v2, mindim, dim2, agg); + } + else { + agg = preNormMBR(mbr2, mindim, dim2, agg); + } + } + return Math.pow(agg, invp); + } + + @Override + public boolean isMetric() { + return (p >= 1.); + } + + @Override + public String toString() { + return "L_" + p + "Norm"; + } + + /** + * Get the functions p parameter. + * + * @return p + */ + public double getP() { + return p; + } + + @Override + public boolean equals(Object obj) { + if(obj == null) { + return false; + } + if(obj instanceof LPNormDistanceFunction) { + return this.p == ((LPNormDistanceFunction) obj).p; + } + return false; + } + + @Override + public SimpleTypeInformation<? super NumberVector> getInputTypeRestriction() { + return TypeUtil.NUMBER_VECTOR_VARIABLE_LENGTH; + } + + /** + * Parameterization class. + * + * @author Erich Schubert + * + * @apiviz.exclude + */ + public static class Parameterizer extends AbstractParameterizer { + /** + * OptionID for the "p" parameter + */ + public static final OptionID P_ID = new OptionID("lpnorm.p", "the degree of the L-P-Norm (positive number)"); + /** + * The value of p. + */ + protected double p; + + @Override + protected void makeOptions(Parameterization config) { + super.makeOptions(config); + final DoubleParameter paramP = new DoubleParameter(P_ID); + paramP.addConstraint(CommonConstraints.GREATER_THAN_ZERO_DOUBLE); + if(config.grab(paramP)) { + p = paramP.getValue(); + } + } + + @Override + protected LPNormDistanceFunction makeInstance() { + if(p == 1.) { + return ManhattanDistanceFunction.STATIC; + } + if(p == 2.) { + return EuclideanDistanceFunction.STATIC; + } + if(p == Double.POSITIVE_INFINITY) { + return MaximumDistanceFunction.STATIC; + } + if(p == Math.round(p)) { + return new LPIntegerNormDistanceFunction((int) p); + } + return new LPNormDistanceFunction(p); + } + } +} |