Mercurial > dive4elements > river
changeset 6777:48f6780c372d
S/Q relation: More Excel compat.
author | Sascha L. Teichmann <teichmann@intevation.de> |
---|---|
date | Wed, 07 Aug 2013 19:36:05 +0200 (2013-08-07) |
parents | c146fd412f9d |
children | cbe9ac4380a5 |
files | artifacts/src/main/java/org/dive4elements/river/artifacts/model/sq/Fitting.java |
diffstat | 1 files changed, 57 insertions(+), 37 deletions(-) [+] |
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--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/model/sq/Fitting.java Wed Aug 07 18:24:07 2013 +0200 +++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/model/sq/Fitting.java Wed Aug 07 19:36:05 2013 +0200 @@ -9,7 +9,6 @@ package org.dive4elements.river.artifacts.model.sq; import org.dive4elements.river.artifacts.math.fitting.Function; -import org.dive4elements.river.artifacts.math.fitting.Linear; import java.util.ArrayList; import java.util.List; @@ -18,9 +17,8 @@ import org.apache.commons.math.optimization.fitting.CurveFitter; -import org.apache.commons.math.optimization.general.AbstractLeastSquaresOptimizer; -import org.apache.commons.math.optimization.general.GaussNewtonOptimizer; import org.apache.commons.math.optimization.general.LevenbergMarquardtOptimizer; +import org.apache.commons.math.stat.regression.SimpleRegression; import org.apache.log4j.Logger; @@ -82,53 +80,75 @@ @Override public void initialize(List<SQ> sqs) throws MathException { - AbstractLeastSquaresOptimizer optimizer = getOptimizer(); + if (USE_NON_LINEAR_FITTING + || function.getInitialGuess().length != 2) { + nonLinearFitting(sqs); + } + else { + linearFitting(sqs); + } + } + + protected void linearFitting(List<SQ> sqs) { + + coeffs = linearRegression(sqs); + + instance = function.instantiate(coeffs); + } + + protected double [] linearRegression(List<SQ> sqs) { + + SimpleRegression reg = new SimpleRegression(); + + int invalidPoints = 0; + for (SQ sq: sqs) { + double s = sq.getS(); + double q = sq.getQ(); + if (s <= 0d || q <= 0d) { + ++invalidPoints; + continue; + } + reg.addData(Math.log(q), Math.log(s)); + } + + if (sqs.size() - invalidPoints < 2) { + log.debug("not enough points"); + return new double [] { 0, 0 }; + } + + double a = Math.exp(reg.getIntercept()); + double b = reg.getSlope(); + + if (log.isDebugEnabled()) { + log.debug("invalid points: " + + invalidPoints + " (" + sqs.size() + ")"); + log.debug("a: " + a + " (" + Math.log(a) + ")"); + log.debug("b: " + b); + } + + return new double [] { a, b }; + } + + + protected void nonLinearFitting(List<SQ> sqs) throws MathException { + + LevenbergMarquardtOptimizer optimizer = + new LevenbergMarquardtOptimizer(); CurveFitter cf = new CurveFitter(optimizer); - double [] values = new double[2]; + for (SQ sq: sqs) { - values[0] = sq.getQ(); - values[1] = sq.getS(); - transformInputValues(values); - cf.addObservedPoint(values[0], values[1]); + cf.addObservedPoint(sq.getS(), sq.getQ()); } coeffs = cf.fit( function, function.getInitialGuess()); - transformCoeffsBack(coeffs); - instance = function.instantiate(coeffs); chiSqr = optimizer.getChiSquare(); } - protected Function getFunction(Function function) { - return USE_NON_LINEAR_FITTING - ? function - : Linear.INSTANCE; - } - - protected void transformInputValues(double [] values) { - if (!USE_NON_LINEAR_FITTING) { - for (int i = 0; i < values.length; ++i) { - values[i] = Math.log(values[i]); - } - } - } - - protected AbstractLeastSquaresOptimizer getOptimizer() { - return USE_NON_LINEAR_FITTING - ? new LevenbergMarquardtOptimizer() - : new GaussNewtonOptimizer(false); - } - - protected void transformCoeffsBack(double [] coeffs) { - if (!USE_NON_LINEAR_FITTING && coeffs.length > 0) { - coeffs[0] = Math.exp(coeffs[0]); - } - } - @Override public double eval(SQ sq) { double s = instance.value(sq.q);