001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/processing/raster/interpolation/InverseDistanceToPower.java $
002 /*----------------------------------------------------------------------------
003 This file is part of deegree, http://deegree.org/
004 Copyright (C) 2001-2009 by:
005 Department of Geography, University of Bonn
006 and
007 lat/lon GmbH
008
009 This library is free software; you can redistribute it and/or modify it under
010 the terms of the GNU Lesser General Public License as published by the Free
011 Software Foundation; either version 2.1 of the License, or (at your option)
012 any later version.
013 This library is distributed in the hope that it will be useful, but WITHOUT
014 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016 details.
017 You should have received a copy of the GNU Lesser General Public License
018 along with this library; if not, write to the Free Software Foundation, Inc.,
019 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020
021 Contact information:
022
023 lat/lon GmbH
024 Aennchenstr. 19, 53177 Bonn
025 Germany
026 http://lat-lon.de/
027
028 Department of Geography, University of Bonn
029 Prof. Dr. Klaus Greve
030 Postfach 1147, 53001 Bonn
031 Germany
032 http://www.geographie.uni-bonn.de/deegree/
033
034 e-mail: info@deegree.org
035 ----------------------------------------------------------------------------*/
036 package org.deegree.processing.raster.interpolation;
037
038 import java.util.ArrayList;
039 import java.util.Collections;
040 import java.util.List;
041
042 import org.deegree.datatypes.values.Interval;
043 import org.deegree.datatypes.values.Values;
044 import org.deegree.io.quadtree.IndexException;
045 import org.deegree.io.quadtree.Quadtree;
046 import org.deegree.model.spatialschema.Envelope;
047 import org.deegree.model.spatialschema.GeometryFactory;
048
049 /**
050 * Class for interpolating a set of data tuples (x, y, value) onto a grid using Inverse Distance to
051 * Power algorithm
052 *
053 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
054 * @author last edited by: $Author: mschneider $
055 *
056 * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
057 */
058 public class InverseDistanceToPower extends Interpolation {
059
060 private double power = 2;
061
062 /**
063 *
064 * @param data
065 * @param power
066 */
067 public InverseDistanceToPower( Quadtree<?> data, double power ) {
068 super( data );
069 this.power = power;
070 }
071
072 /**
073 *
074 * @param data
075 * @param ignoreValues
076 * @param power
077 */
078 public InverseDistanceToPower( Quadtree<?> data, Values ignoreValues, double power ) {
079 super( data, ignoreValues );
080 this.power = power;
081 }
082
083 /**
084 *
085 * @param data
086 * @param ignoreValues
087 * @param searchRadius1
088 * @param searchRadius2
089 * @param searchRadiusAngle
090 * @param minData
091 * @param maxData
092 * @param noValue
093 * @param autoincreaseSearchRadius1
094 * @param autoincreaseSearchRadius2
095 * @param power
096 */
097 public InverseDistanceToPower( Quadtree<?> data, Values ignoreValues, double searchRadius1, double searchRadius2,
098 double searchRadiusAngle, int minData, int maxData, double noValue,
099 double autoincreaseSearchRadius1, double autoincreaseSearchRadius2, double power ) {
100 super( data, ignoreValues, searchRadius1, searchRadius2, searchRadiusAngle, minData, maxData, noValue,
101 autoincreaseSearchRadius1, autoincreaseSearchRadius2 );
102 this.power = power;
103 }
104
105 /**
106 * calculates the interpolated value for a position defined by x and y
107 *
108 * @param x
109 * @param y
110 * @return the interpolated value
111 * @throws InterpolationException
112 */
113 @Override
114 public double calcInterpolatedValue( double x, double y, double searchRadius1, double searchRadius2 )
115 throws InterpolationException {
116 double tmpSR1 = searchRadius1;
117 double tmpSR2 = searchRadius2;
118
119 try {
120 Envelope searchRadius = GeometryFactory.createEnvelope( x - tmpSR1, y - tmpSR2, x + tmpSR1, y + tmpSR2,
121 null );
122 List<?> foundValues = data.query( searchRadius );
123
124 List<DataTuple> values = new ArrayList<DataTuple>();
125 for ( Object obj : foundValues ) {
126 DataTuple tuple = (DataTuple) obj;
127
128 boolean ignore = false;
129
130 if ( ignoreValues != null && ignoreValues.getInterval().length > 0 ) {
131 for ( Interval interval : ignoreValues.getInterval() ) {
132 double min = Double.parseDouble( interval.getMin().getValue() );
133 double max = Double.parseDouble( interval.getMax().getValue() );
134 if ( tuple.value > min && tuple.value < max ) {
135 ignore = true;
136 }
137 }
138 }
139
140 if ( !ignore ) {
141 double dx = Math.abs( tuple.x - x );
142 double dy = Math.abs( tuple.y - y );
143 /*
144 * if ( dx == 0 && dy == 0 ) { // System.out.println( "Call with already
145 * existing value!" ); return tuple.value; }
146 */
147 double dist = Math.sqrt( dx * dx + dy * dy );
148 double weight = Math.pow( dist, power );
149 values.add( new DataTuple( dist, tuple.value, weight ) );
150 }
151 }
152
153 if ( values.size() < minData ) {
154 if ( autoincreaseSearchRadius1 == 0 && autoincreaseSearchRadius2 == 0 ) {
155 return noValue;
156 }
157
158 tmpSR1 += autoincreaseSearchRadius1;
159 tmpSR2 += autoincreaseSearchRadius2;
160 // System.out.print( " Increasing the search radius to " + tmpSR1 + " and " + tmpSR2
161 // +"\r" );
162 return calcInterpolatedValue( x, y, tmpSR1, tmpSR2 );
163 }
164
165 if ( values.size() > maxData ) {
166 Collections.sort( values );
167 values = values.subList( 0, maxData );
168 }
169
170 double valueSum = 0;
171
172 double weightSum = 0;
173
174 for ( Object obj : values ) {
175 // in the data tuple, x is interpreted as the distance, y is the value and
176 // "value" is the weight
177 DataTuple tuple = (DataTuple) obj;
178 valueSum += ( tuple.y / tuple.value );
179 weightSum += ( 1 / tuple.value );
180 }
181
182 double result = ( valueSum / weightSum );
183
184 if ( Double.isInfinite( result ) ) {
185 return noValue;
186 }
187
188 if ( Double.isNaN( result ) ) {
189 return noValue;
190 }
191
192 return result;
193 } catch ( IndexException e ) {
194 throw new InterpolationException( e );
195 }
196 }
197 }