sascha@326: package de.intevation.flys.artifacts.model;
sascha@326: 
sascha@326: import java.io.Serializable;
sascha@326: 
sascha@326: 
sascha@427: import de.intevation.flys.artifacts.math.LinearRemap;
sascha@427: 
sascha@335: import java.util.Arrays;
sascha@326: import java.util.ArrayList;
sascha@326: import java.util.List;
sascha@326: import java.util.Collections;
sascha@326: 
sascha@339: import org.apache.log4j.Logger;
sascha@339: 
sascha@339: import org.apache.commons.math.analysis.interpolation.SplineInterpolator;
sascha@339: 
sascha@339: import org.apache.commons.math.analysis.polynomials.PolynomialSplineFunction;
sascha@339: 
sascha@339: import org.apache.commons.math.ArgumentOutsideDomainException;
sascha@339: 
sascha@326: public class WstValueTable
sascha@326: implements   Serializable
sascha@326: {
sascha@339:     private static Logger log = Logger.getLogger(WstValueTable.class);
sascha@326: 
sascha@395:     public static final int DEFAULT_Q_STEPS = 500;
sascha@339: 
sascha@633:     public static final class Column
sascha@633:     implements                Serializable
sascha@326:     {
sascha@326:         protected String name;
sascha@326: 
sascha@632:         protected QRangeTree qRangeTree;
sascha@632: 
sascha@326:         public Column() {
sascha@326:         }
sascha@326: 
sascha@326:         public Column(String name) {
sascha@326:             this.name = name;
sascha@326:         }
sascha@326: 
sascha@326:         public String getName() {
sascha@326:             return name;
sascha@326:         }
sascha@326: 
sascha@326:         public void setName(String name) {
sascha@326:             this.name = name;
sascha@326:         }
sascha@632: 
sascha@632:         public QRangeTree getQRangeTree() {
sascha@632:             return qRangeTree;
sascha@632:         }
sascha@632: 
sascha@632:         public void setQRangeTree(QRangeTree qRangeTree) {
sascha@632:             this.qRangeTree = qRangeTree;
sascha@632:         }
sascha@633:     } // class Column
sascha@326: 
sascha@633:     public static final class QPosition {
sascha@426: 
sascha@426:         protected int    index;
sascha@426:         protected double weight;
sascha@426: 
sascha@426:         public QPosition() {
sascha@426:         }
sascha@426: 
sascha@633:         public QPosition(int index, double weight) {
sascha@426:             this.index  = index;
sascha@426:             this.weight = weight;
sascha@426:         }
sascha@426: 
sascha@633:         public QPosition set(int index, double weight) {
sascha@633:             this.index  = index;
sascha@633:             this.weight = weight;
sascha@633:             return this;
sascha@633:         }
sascha@633: 
sascha@426:     } // class Position
sascha@426: 
sascha@633:     public static final class Row
sascha@633:     implements                Serializable, Comparable<Row>
sascha@326:     {
sascha@326:         double    km;
sascha@335:         double [] ws;
sascha@326: 
sascha@326:         public Row() {
sascha@326:         }
sascha@326: 
sascha@335:         public Row(double km) {
sascha@326:             this.km = km;
sascha@335:         }
sascha@335: 
sascha@633:         public Row(double km, double [] ws) {
sascha@335:             this(km);
sascha@335:             this.ws = ws;
sascha@335:         }
sascha@335: 
sascha@335:         public int compareTo(Row other) {
sascha@335:             double d = km - other.km;
sascha@458:             if (d < -0.0001) return -1;
sascha@458:             if (d >  0.0001) return +1;
sascha@335:             return 0;
sascha@326:         }
sascha@339: 
sascha@633:         public void interpolateW(
sascha@633:             Row           other,
sascha@633:             double        km,
sascha@633:             double []     iqs,
sascha@633:             double []     ows,
sascha@633:             WstValueTable table
sascha@633:         ) {
sascha@633:             double kmWeight = factor(km, this.km, other.km);
sascha@339: 
sascha@633:             QPosition qPosition = new QPosition();
sascha@633: 
sascha@633:             for (int i = 0; i < iqs.length; ++i) {
sascha@633:                 if (table.getQPosition(km, iqs[i], qPosition) != null) {
sascha@633:                     double wt =       getW(qPosition);
sascha@633:                     double wo = other.getW(qPosition);
sascha@633:                     ows[i] = weight(kmWeight, wt, wo);
sascha@633:                 }
sascha@633:                 else {
sascha@633:                     ows[i] = Double.NaN;
sascha@633:                 }
sascha@633:             }
sascha@633:         }
sascha@633: 
sascha@633:         public double [][] interpolateWQ(
sascha@633:             Row           other,
sascha@633:             double        km,
sascha@633:             int           steps,
sascha@633:             WstValueTable table
sascha@633:         ) {
sascha@395:             int W = Math.min(ws.length, other.ws.length);
sascha@339: 
sascha@339:             if (W < 1) {
sascha@339:                 return new double[2][0];
sascha@339:             }
sascha@339: 
sascha@339:             double factor = factor(km, this.km, other.km);
sascha@339: 
sascha@395:             double [] splineQ = new double[W];
sascha@395:             double [] splineW = new double[W];
sascha@339: 
sascha@395:             double minQ =  Double.MAX_VALUE;
sascha@395:             double maxQ = -Double.MAX_VALUE;
sascha@339: 
sascha@339:             for (int i = 0; i < W; ++i) {
sascha@395:                 double wws = weight(factor, ws[i], other.ws[i]);
sascha@633:                 double wqs = weight(
sascha@633:                     factor,
sascha@633:                     table.getQIndex(i, km),
sascha@633:                     table.getQIndex(i, other.km));
sascha@633: 
sascha@395:                 splineW[i] = wws;
sascha@395:                 splineQ[i] = wqs;
sascha@395:                 if (wqs < minQ) minQ = wqs;
sascha@395:                 if (wqs > maxQ) maxQ = wqs;
sascha@339:             }
sascha@339: 
sascha@395:             double stepWidth = (maxQ - minQ)/steps;
sascha@395: 
sascha@339:             SplineInterpolator interpolator = new SplineInterpolator();
sascha@395:             PolynomialSplineFunction spline =
sascha@395:                 interpolator.interpolate(splineQ, splineW);
sascha@339: 
sascha@395:             double [] outWs = new double[steps];
sascha@395:             double [] outQs = new double[steps];
sascha@339: 
sascha@339:             try {
sascha@395:                 double q = minQ;
sascha@395:                 for (int i = 0; i < outWs.length; ++i, q += stepWidth) {
sascha@395:                     outWs[i] = spline.value(outQs[i] = q);
sascha@339:                 }
sascha@339:             }
sascha@339:             catch (ArgumentOutsideDomainException aode) {
sascha@339:                 log.error("Spline interpolation failed.", aode);
sascha@339:             }
sascha@339: 
sascha@339:             return new double [][] { outWs, outQs };
sascha@339:         }
sascha@339: 
sascha@633:         public double [][] interpolateWQ(int steps, WstValueTable table) {
sascha@395: 
sascha@395:             int W = ws.length;
sascha@339: 
sascha@339:             if (W < 1) {
sascha@339:                 return new double[2][0];
sascha@339:             }
sascha@339: 
sascha@395:             double [] splineQ = new double[W];
sascha@395: 
sascha@395:             double minQ =  Double.MAX_VALUE; 
sascha@395:             double maxQ = -Double.MAX_VALUE; 
sascha@339: 
sascha@633:             QPosition qPosition = new QPosition();
sascha@633: 
sascha@339:             for (int i = 0; i < W; ++i) {
sascha@633:                 splineQ[i] = table.getQIndex(i, km);
sascha@633:                 if (splineQ[i] < minQ) minQ = splineQ[i];
sascha@633:                 if (splineQ[i] > maxQ) maxQ = splineQ[i];
sascha@339:             }
sascha@339: 
sascha@395:             double stepWidth = (maxQ - minQ)/steps;
sascha@395: 
sascha@339:             SplineInterpolator interpolator = new SplineInterpolator();
sascha@339: 
sascha@395:             PolynomialSplineFunction spline =
sascha@633:                 interpolator.interpolate(splineQ, ws);
sascha@339: 
sascha@395:             double [] outWs = new double[steps];
sascha@395:             double [] outQs = new double[steps];
sascha@339: 
sascha@339:             try {
sascha@395:                 double q = minQ;
sascha@395:                 for (int i = 0; i < outWs.length; ++i, q += stepWidth) {
sascha@395:                     outWs[i] = spline.value(outQs[i] = q);
sascha@339:                 }
sascha@339:             }
sascha@339:             catch (ArgumentOutsideDomainException aode) {
sascha@339:                 log.error("Spline interpolation failed.", aode);
sascha@339:             }
sascha@339: 
sascha@339:             return new double [][] { outWs, outQs };
sascha@339:         }
sascha@339: 
sascha@426: 
sascha@633:         public double getW(QPosition qPosition) {
sascha@633:             int    index  = qPosition.index;
sascha@633:             double weight = qPosition.weight;
sascha@426: 
sascha@633:             return weight == 1.0
sascha@633:                 ? ws[index]
sascha@633:                 : weight(weight, ws[index-1], ws[index]);
sascha@426:         }
sascha@426: 
sascha@633:         public double getW(
sascha@426:             Row       other,
sascha@426:             double    km,
sascha@633:             QPosition qPosition
sascha@426:         ) {
sascha@426:             double kmWeight = factor(km, this.km, other.km);
sascha@426: 
sascha@633:             int    index  = qPosition.index;
sascha@633:             double weight = qPosition.weight;
sascha@426: 
sascha@633:             double tw, ow;
sascha@426: 
sascha@633:             if (weight == 1.0) {
sascha@633:                 tw = ws[index];
sascha@633:                 ow = other.ws[index];
sascha@426:             }
sascha@426:             else {
sascha@633:                 tw = weight(weight, ws[index-1], ws[index]); 
sascha@633:                 ow = weight(weight, other.ws[index-1], other.ws[index]); 
sascha@426:             }
sascha@426: 
sascha@633:             return weight(kmWeight, tw, ow);
sascha@427:         }
sascha@633:     } // class Row
sascha@326: 
sascha@326:     protected List<Row> rows;
sascha@326: 
sascha@326:     protected Column [] columns;
sascha@326: 
sascha@326:     public WstValueTable() {
sascha@326:         rows = new ArrayList<Row>();
sascha@326:     }
sascha@326: 
sascha@326:     public WstValueTable(Column [] columns) {
sascha@326:         this();
sascha@326:         this.columns = columns;
sascha@326:     }
sascha@326: 
sascha@633:     public WstValueTable(Column [] columns, List<Row> rows) {
sascha@633:         this.columns = columns;
sascha@633:         this.rows    = rows;
sascha@633:     }
sascha@633: 
sascha@458:     public void sortRows() {
sascha@458:         Collections.sort(rows);
sascha@458:     }
sascha@458: 
sascha@380:     public double [] interpolateW(double km, double [] qs, double [] ws) {
sascha@335: 
sascha@335:         int rowIndex = Collections.binarySearch(rows, new Row(km));
sascha@335: 
sascha@633:         QPosition qPosition = new QPosition();
sascha@633: 
sascha@335:         if (rowIndex >= 0) { // direct row match
sascha@335:             Row row = rows.get(rowIndex);
sascha@335:             for (int i = 0; i < qs.length; ++i) {
sascha@633:                 ws[i] = getQPosition(km, qs[i], qPosition) != null
sascha@633:                     ? row.getW(qPosition)
sascha@633:                     : Double.NaN;
sascha@335:             }
sascha@335:         }
sascha@335:         else { // needs bilinear interpolation
sascha@335:             rowIndex = -rowIndex -1;
sascha@335: 
sascha@335:             if (rowIndex < 1 || rowIndex >= rows.size()) {
sascha@335:                 // do not extrapolate
sascha@335:                 Arrays.fill(ws, Double.NaN);
sascha@335:             }
sascha@335:             else {
sascha@633:                 Row r1 = rows.get(rowIndex-1);
sascha@633:                 Row r2 = rows.get(rowIndex);
sascha@633:                 r1.interpolateW(r2, km, qs, ws, this);
sascha@335:             }
sascha@335:         }
sascha@335: 
sascha@335:         return ws;
sascha@335:     }
sascha@335: 
sascha@339:     public double [][] interpolateWQ(double km) {
sascha@395:         return interpolateWQ(km, DEFAULT_Q_STEPS);
sascha@339:     }
sascha@339: 
sascha@395:     public double [][] interpolateWQ(double km, int steps) {
sascha@395: 
sascha@339:         int rowIndex = Collections.binarySearch(rows, new Row(km));
sascha@339: 
sascha@339:         if (rowIndex >= 0) { // direct row match
sascha@339:             Row row = rows.get(rowIndex);
sascha@633:             return row.interpolateWQ(steps, this);
sascha@339:         }
sascha@339: 
sascha@339:         rowIndex = -rowIndex -1;
sascha@339: 
sascha@339:         if (rowIndex < 1 || rowIndex >= rows.size()) {
sascha@339:             // do not extrapolate
sascha@339:             return new double[2][0];
sascha@339:         }
sascha@339: 
sascha@339:         Row r1 = rows.get(rowIndex-1);
sascha@339:         Row r2 = rows.get(rowIndex);
sascha@339: 
sascha@633:         return r1.interpolateWQ(r2, km, steps, this);
sascha@339:     }
sascha@339: 
sascha@427:     public void interpolate(
sascha@427:         double []   kms,
sascha@427:         double []   ws,
sascha@427:         double []   qs,
sascha@427:         QPosition   qPosition,
sascha@427:         LinearRemap remap
sascha@427:     ) {
sascha@649:         interpolate(kms, ws, qs, qPosition, remap, 0, kms.length);
sascha@649:     }
sascha@649: 
sascha@649:     public void interpolate(
sascha@649:         double []   kms,
sascha@649:         double []   ws,
sascha@649:         double []   qs,
sascha@649:         QPosition   qPosition,
sascha@649:         LinearRemap remap,
sascha@649:         int         startIndex,
sascha@649:         int         length
sascha@649:     ) {
sascha@427:         int R1 = rows.size()-1;
sascha@427: 
sascha@427:         Row kmKey = new Row();
sascha@633: 
sascha@633:         QPosition nPosition = new QPosition();
sascha@633: 
sascha@649:         for (int i = startIndex, end = startIndex+length; i < end; ++i) {
sascha@427:             kmKey.km = kms[i];
sascha@633: 
sascha@633:             qs[i] = remap.eval(kms[i], getQ(qPosition, kms[i]));
sascha@633: 
sascha@633:             if (getQPosition(kms[i], qs[i], nPosition) == null) {
sascha@633:                 ws[i] = Double.NaN;
sascha@633:                 continue;
sascha@633:             }
sascha@633: 
sascha@427:             int rowIndex = Collections.binarySearch(rows, kmKey);
sascha@427: 
sascha@427:             if (rowIndex >= 0) {
sascha@427:                 // direct row match
sascha@633:                 ws[i] = rows.get(rowIndex).getW(nPosition);
sascha@427:                 continue;
sascha@427:             }
sascha@427: 
sascha@427:             rowIndex = -rowIndex -1;
sascha@427: 
sascha@427:             if (rowIndex < 1 || rowIndex >= R1) {
sascha@427:                 // do not extrapolate
sascha@633:                 ws[i] = Double.NaN;
sascha@427:                 continue;
sascha@427:             }
sascha@427:             Row r1 = rows.get(rowIndex-1);
sascha@427:             Row r2 = rows.get(rowIndex);
sascha@633:             ws[i] = r1.getW(r2, kms[i], nPosition);
sascha@427:         }
sascha@427:     }
sascha@427: 
sascha@427:     public QPosition interpolate(
sascha@426:         double    q,
sascha@645:         double    referenceKm,
sascha@426:         double [] kms,
sascha@426:         double [] ws,
sascha@426:         double [] qs
sascha@426:     ) {
sascha@649:         return interpolate(q, referenceKm, kms, ws, qs, 0, kms.length);
sascha@649:     }
sascha@649: 
sascha@649:     public QPosition interpolate(
sascha@649:         double    q,
sascha@649:         double    referenceKm,
sascha@649:         double [] kms,
sascha@649:         double [] ws,
sascha@649:         double [] qs,
sascha@649:         int       startIndex,
sascha@649:         int       length
sascha@649:     ) {
sascha@645:         QPosition qPosition = getQPosition(referenceKm, q);
sascha@426: 
sascha@426:         if (qPosition == null) {
sascha@633:             // we cannot locate q at km
sascha@427:             return null;
sascha@426:         }
sascha@426: 
sascha@645:         Row kmKey = new Row();
sascha@645: 
sascha@645:         int R1 = rows.size()-1;
sascha@645: 
sascha@649:         for (int i = startIndex, end = startIndex+length; i < end; ++i) {
sascha@426:             kmKey.km = kms[i];
sascha@458: 
sascha@645:             int rowIndex = Collections.binarySearch(rows, kmKey);
sascha@426: 
sascha@633:             qs[i] = getQ(qPosition, kms[i]);
sascha@633: 
sascha@426:             if (rowIndex >= 0) {
sascha@426:                 // direct row match
sascha@633:                 ws[i] = rows.get(rowIndex).getW(qPosition);
sascha@426:                 continue;
sascha@426:             }
sascha@426: 
sascha@426:             rowIndex = -rowIndex -1;
sascha@426: 
sascha@426:             if (rowIndex < 1 || rowIndex >= R1) {
sascha@426:                 // do not extrapolate
sascha@633:                 ws[i] =  Double.NaN;
sascha@426:                 continue;
sascha@426:             }
sascha@426:             Row r1 = rows.get(rowIndex-1);
sascha@426:             Row r2 = rows.get(rowIndex);
sascha@633: 
sascha@633:             ws[i] = r1.getW(r2, kms[i], qPosition);
sascha@426:         }
sascha@426: 
sascha@427:         return qPosition;
sascha@426:     }
sascha@633: 
sascha@633:     public QPosition getQPosition(double km, double q) {
sascha@633:         return getQPosition(km, q, new QPosition());
sascha@633:     }
sascha@633: 
sascha@633:     public QPosition getQPosition(double km, double q, QPosition qPosition) {
sascha@633: 
sascha@633:         if (columns.length == 0) {
sascha@633:             return null;
sascha@633:         }
sascha@633: 
sascha@633:         double qLast = columns[0].getQRangeTree().findQ(km);
sascha@633: 
sascha@633:         if (Math.abs(qLast - q) < 0.00001) {
sascha@633:             return qPosition.set(0, 1d);
sascha@633:         }
sascha@633: 
sascha@633:         for (int i = 1; i < columns.length; ++i) {
sascha@633:             double qCurrent = columns[i].getQRangeTree().findQ(km);
sascha@633:             if (Math.abs(qCurrent - q) < 0.00001) {
sascha@633:                 return qPosition.set(i, 1d);
sascha@633:             }
sascha@633: 
sascha@633:             double qMin, qMax;
sascha@633:             if (qLast < qCurrent) { qMin = qLast; qMax = qCurrent; }
sascha@633:             else                  { qMin = qCurrent; qMax = qLast; }
sascha@633: 
sascha@633:             if (q > qMin && q < qMax) {
sascha@633:                 double weight = factor(q, qLast, qCurrent);
sascha@633:                 return qPosition.set(i, weight);
sascha@633:             }
sascha@633:             qLast = qCurrent;
sascha@633:         }
sascha@633: 
sascha@633:         return null;
sascha@633:     }
sascha@633: 
sascha@633:     public double getQIndex(int index, double km) {
sascha@633:         return columns[index].getQRangeTree().findQ(km);
sascha@633:     }
sascha@633: 
sascha@633:     public double getQ(QPosition qPosition, double km) {
sascha@633:         int    index  = qPosition.index;
sascha@633:         double weight = qPosition.weight;
sascha@633: 
sascha@633:         if (weight == 1d) {
sascha@633:             return columns[index].getQRangeTree().findQ(km);
sascha@633:         }
sascha@633:         double q1 = columns[index-1].getQRangeTree().findQ(km);
sascha@633:         double q2 = columns[index  ].getQRangeTree().findQ(km);
sascha@633:         return weight(weight, q1, q2);
sascha@633:     }
sascha@633: 
sascha@633:     public static final double linear(
sascha@633:         double x,
sascha@633:         double x1, double x2,
sascha@633:         double y1, double y2
sascha@633:     ) {
sascha@633:         // y1 = m*x1 + b
sascha@633:         // y2 = m*x2 + b
sascha@633:         // y2 - y1 = m*(x2 - x1)
sascha@633:         // m = (y2 - y1)/(x2 - x1) # x2 != x1
sascha@633:         // b = y1 - m*x1
sascha@633: 
sascha@633:         if (x1 == x2) {
sascha@633:             return 0.5*(y1 + y2);
sascha@633:         }
sascha@633:         double m = (y2 - y1)/(x2 - x1);
sascha@633:         double b = y1 - m*x1;
sascha@633:         return x*m + b;
sascha@633:     }
sascha@633: 
sascha@633:     public static final double factor(double x, double p1, double p2) {
sascha@633:         // 0 = m*p1 + b <=> b = -m*p1
sascha@633:         // 1 = m*p2 + b
sascha@633:         // 1 = m*(p2 - p1)
sascha@633:         // m = 1/(p2 - p1) # p1 != p2
sascha@633:         // f(x) = x/(p2-p1) - p1/(p2-p1) <=> (x-p1)/(p2-p1)
sascha@633: 
sascha@633:         return p1 == p2 ? 0.0 : (x-p1)/(p2-p1);
sascha@633:     }
sascha@633: 
sascha@633:     public static final double weight(double factor, double a, double b) {
sascha@633:         //return (1.0-factor)*a + factor*b;
sascha@633:         return a + factor*(b-a);
sascha@633:     }
sascha@326: }
sascha@326: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :