PolynomialRobustEstimator.java
/*
* Copyright (C) 2016 Alberto Irurueta Carro (alberto@irurueta.com)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.irurueta.numerical.polynomials.estimators;
import com.irurueta.numerical.LockedException;
import com.irurueta.numerical.NotReadyException;
import com.irurueta.numerical.polynomials.Polynomial;
import com.irurueta.numerical.robust.RobustEstimatorException;
import com.irurueta.numerical.robust.RobustEstimatorMethod;
import java.util.List;
/**
* This is an abstract class for algorithms to robustly find the best
* Polynomial for provided collection of evaluations.
* Implementations of this class should be able to detect and discard outliers
* in order to find the best solution.
*/
@SuppressWarnings("Duplicates")
public abstract class PolynomialRobustEstimator {
/**
* Default robust estimator method when none is provided.
* In general for Polynomial estimation is best to use PROSAC or RANSAC
* than any other method, as it provides more robust methods.
*/
public static final RobustEstimatorMethod DEFAULT_ROBUST_METHOD = RobustEstimatorMethod.PROSAC;
/**
* Default amount of progress variation before notifying a change in
* estimation progress. By default, this is set to 5%.
*/
public static final float DEFAULT_PROGRESS_DELTA = 0.05f;
/**
* Minimum allowed value for progress delta.
*/
public static final float MIN_PROGRESS_DELTA = 0.0f;
/**
* Maximum allowed value for progress delta.
*/
public static final float MAX_PROGRESS_DELTA = 1.0f;
/**
* Constant defining default confidence of the estimated result, which is
* 99%. This means that with a probability of 99% estimation will be
* accurate because chosen sub-samples will be inliers.
*/
public static final double DEFAULT_CONFIDENCE = 0.99;
/**
* Default maximum allowed number of iterations.
*/
public static final int DEFAULT_MAX_ITERATIONS = 5000;
/**
* Minimum allowed confidence value.
*/
public static final double MIN_CONFIDENCE = 0.0;
/**
* Maximum allowed confidence value.
*/
public static final double MAX_CONFIDENCE = 1.0;
/**
* Minimum allowed number of iterations.
*/
public static final int MIN_ITERATIONS = 1;
/**
* Flag indicating whether geometric distance is used by default or not
* to find outliers.
*/
public static final boolean DEFAULT_USE_GEOMETRIC_DISTANCE = false;
/**
* Collection of polynomial evaluations and their corresponding point of
* evaluation used to determine a polynomial of required degree.
*/
protected List<PolynomialEvaluation> evaluations;
/**
* Internal non robust estimator of polynomial estimator.
*/
protected final LMSEPolynomialEstimator polynomialEstimator;
/**
* Listener to be notified of events such as when estimation starts, ends or
* its progress significantly changes.
*/
protected PolynomialRobustEstimatorListener listener;
/**
* Indicates if this estimator is locked because an estimation is being
* computed.
*/
protected boolean locked;
/**
* Amount of progress variation before notifying a progress change during
* estimation.
*/
protected float progressDelta;
/**
* Amount of confidence expressed as a value between 0.0 and 1.0 (which is
* equivalent to 100%). The amount of confidence indicates the probability
* that the estimated result is correct. Usually this value will be close
* to 1.0, but not exactly 1.0.
*/
protected double confidence;
/**
* Maximum allowed number of iterations. When the maximum number of
* iterations is exceeded, result will not be available, however an
* approximate result will be available for retrieval.
*/
protected int maxIterations;
/**
* Indicates whether geometric distance will be used to find outliers or
* algebraic distance will be used instead.
*/
protected boolean useGeometricDistance;
/**
* Constructor.
*/
protected PolynomialRobustEstimator() {
progressDelta = DEFAULT_PROGRESS_DELTA;
confidence = DEFAULT_CONFIDENCE;
maxIterations = DEFAULT_MAX_ITERATIONS;
useGeometricDistance = DEFAULT_USE_GEOMETRIC_DISTANCE;
polynomialEstimator = new LMSEPolynomialEstimator();
}
/**
* Constructor.
*
* @param degree degree of polynomial to be estimated.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
protected PolynomialRobustEstimator(final int degree) {
progressDelta = DEFAULT_PROGRESS_DELTA;
confidence = DEFAULT_CONFIDENCE;
maxIterations = DEFAULT_MAX_ITERATIONS;
useGeometricDistance = DEFAULT_USE_GEOMETRIC_DISTANCE;
polynomialEstimator = new LMSEPolynomialEstimator(degree);
}
/**
* Constructor.
*
* @param evaluations collection of polynomial evaluations.
* @throws IllegalArgumentException if provided number of evaluations is
* less than the required minimum.
*/
protected PolynomialRobustEstimator(final List<PolynomialEvaluation> evaluations) {
this();
internalSetEvaluations(evaluations);
}
/**
* Constructor.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
*/
protected PolynomialRobustEstimator(final PolynomialRobustEstimatorListener listener) {
this();
this.listener = listener;
}
/**
* Constructor.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @throws IllegalArgumentException if provided degree is less than 1 or if
* provided number of evaluations is less than the required minimum for
* provided degree.
*/
protected PolynomialRobustEstimator(
final int degree, final List<PolynomialEvaluation> evaluations) {
this(degree);
internalSetEvaluations(evaluations);
}
/**
* Constructor.
*
* @param degree degree of polynomial to be estimated.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
protected PolynomialRobustEstimator(
final int degree, final PolynomialRobustEstimatorListener listener) {
this(degree);
this.listener = listener;
}
/**
* Constructor.
*
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @throws IllegalArgumentException if provided number of evaluations is
* less than the required minimum.
*/
protected PolynomialRobustEstimator(
final List<PolynomialEvaluation> evaluations, final PolynomialRobustEstimatorListener listener) {
this(evaluations);
this.listener = listener;
}
/**
* Constructor.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events.
* @throws IllegalArgumentException if provided degree is less than 1 or if
* provided number of evaluations is less than the required minimum for
* provided degree.
*/
protected PolynomialRobustEstimator(
final int degree, final List<PolynomialEvaluation> evaluations,
final PolynomialRobustEstimatorListener listener) {
this(degree, evaluations);
this.listener = listener;
}
/**
* Gets collection of polynomial evaluations and their corresponding point
* of evaluation used to determine a polynomial of required degree.
*
* @return collection of polynomial evaluations.
*/
public List<PolynomialEvaluation> getEvaluations() {
return evaluations;
}
/**
* Sets collection of polynomial evaluations and their corresponding point
* of evaluation used to determine a polynomial of required degree.
*
* @param evaluations collection of polynomial evaluations.
* @throws LockedException if estimator is locked.
* @throws IllegalArgumentException if provided list of evaluations does
* not contain enough evaluations to estimate the polynomial using current
* settings.
*/
public void setEvaluations(final List<PolynomialEvaluation> evaluations) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
internalSetEvaluations(evaluations);
}
/**
* Gets minimum number of evaluations required to estimate a polynomial of
* the specified degree.
*
* @return number of required evaluations.
*/
public int getMinNumberOfEvaluations() {
return polynomialEstimator.getMinNumberOfEvaluations();
}
/**
* Gets listener to be notified of events such as when estimation starts,
* ends or its progress significantly changes.
*
* @return listener to be notified of events.
*/
public PolynomialRobustEstimatorListener getListener() {
return listener;
}
/**
* Sets listener to be notified of events such as when estimation starts,
* ends or its progress significantly changes.
*
* @param listener listener to be notified of events.
*/
public void setListener(final PolynomialRobustEstimatorListener listener) {
this.listener = listener;
}
/**
* Indicates if this estimator is locked because an estimation is being
* computed.
*
* @return true if this estimator is locked, false otherwise.
*/
public boolean isLocked() {
return locked;
}
/**
* Returns amount of progress variation before notifying a progress change
* during estimation.
*
* @return amount of progress variation before notifying a progress change
* during estimation.
*/
public float getProgressDelta() {
return progressDelta;
}
/**
* Sets amount of progress variation before notifying a progress change
* during estimation.
*
* @param progressDelta amount of progress variation before notifying a
* progress change during estimation.
* @throws IllegalArgumentException if progress delta is less than zero or
* greater than 1.
* @throws LockedException if this estimator is locked because an estimation
* is being computed.
*/
public void setProgressDelta(final float progressDelta) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
throw new IllegalArgumentException();
}
this.progressDelta = progressDelta;
}
/**
* Returns amount of confidence expressed as a value between 0.0 and 1.0
* (which is equivalent to 100%). The amount of confidence indicates the
* probability that the estimated result is correct. Usually this value will
* be close to 1.0, but not exactly 1.0.
*
* @return amount of confidence as a value between 0.0 and 1.0.
*/
public double getConfidence() {
return confidence;
}
/**
* Sets amount of confidence expressed as a value between 0.0 and 1.0 (which
* is equivalent to 100%). The amount of confidence indicates the
* probability that the estimated result is correct. Usually this value will
* be close to 1.0 but not exactly 1.0.
*
* @param confidence confidence to be set as a value between 0.0 and 1.0.
* @throws IllegalArgumentException if provided value is not between 0.0 and
* 1.0.
* @throws LockedException if this estimator is locked because an estimator
* is being computed.
*/
public void setConfidence(final double confidence) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
throw new IllegalArgumentException();
}
this.confidence = confidence;
}
/**
* Returns maximum allowed number of iterations. If maximum allowed number
* of iterations is achieved without converging to a result when calling
* estimate(), a RobustEstimatorException will be raised.
*
* @return maximum allowed number of iterations.
*/
public int getMaxIterations() {
return maxIterations;
}
/**
* Sets maximum allowed number of iterations. When the maximum number of
* iterations is exceeded, result will not be available, however an
* approximate result will be available for retrieval.
*
* @param maxIterations maximum allowed number of iterations to be set.
* @throws IllegalArgumentException if provided value is less than 1.
* @throws LockedException if this estimator is locked because an estimation
* is being computed.
*/
public void setMaxIterations(final int maxIterations) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
if (maxIterations < MIN_ITERATIONS) {
throw new IllegalArgumentException();
}
this.maxIterations = maxIterations;
}
/**
* Indicates whether geometric distance will be used to find outliers or
* algebraic distance will be used instead.
*
* @return true if geometric distance is used, false otherwise.
*/
public boolean isGeometricDistanceUsed() {
return useGeometricDistance;
}
/**
* Specifies whether geometric distance will be used to find outliers or
* algebraic distance will be used instead.
*
* @param geometricDistanceUsed true if geometric distance is used, false
* otherwise.
* @throws LockedException if this estimator is locked.
*/
public void setGeometricDistanceUsed(final boolean geometricDistanceUsed) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
useGeometricDistance = geometricDistanceUsed;
}
/**
* Gets degree of polynomial to be estimated.
*
* @return degree of polynomial to be estimated.
*/
public int getDegree() {
return polynomialEstimator.getDegree();
}
/**
* Sets degree of polynomial to be estimated.
*
* @param degree degree of polynomial to be estimated.
* @throws IllegalArgumentException if provided degree is less than 1.
* @throws LockedException if this instance is locked.
*/
public void setDegree(final int degree) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
polynomialEstimator.setDegree(degree);
}
/**
* Determines whether estimation is ready to start with the given data and
* required degree of polynomial to be estimated.
*
* @return true if estimator is ready, false otherwise.
*/
public boolean isReady() {
final var nParams = polynomialEstimator.getDegree() + 1;
if (evaluations == null || evaluations.size() < nParams) {
return false;
}
// also ensure that at least a direct or integral evaluation exists
var count = 0;
for (final var eval : evaluations) {
if (eval.getType() == PolynomialEvaluationType.DIRECT_EVALUATION
|| eval.getType() == PolynomialEvaluationType.INTEGRAL_EVALUATION
|| eval.getType() == PolynomialEvaluationType.INTEGRAL_INTERVAL) {
count++;
}
}
return count >= 1 && evaluations.size() >= nParams;
}
/**
* Returns quality scores corresponding to each polynomial evaluation.
* The larger the score value the better the quality of the evaluation.
* This implementation always returns null.
* Subclasses using quality scores must implement proper behaviour.
*
* @return quality scores corresponding to each evaluation.
*/
public double[] getQualityScores() {
// quality scores ignored
return null;
}
/**
* Sets quality scores corresponding to each polynomial evaluation.
* The larger the score value the better the quality of the evaluation.
* This implementation makes no action.
* Subclasses using quality scores must implement proper behaviour.
*
* @param qualityScores quality scores corresponding to each evaluation.
* @throws LockedException if robust estimator is locked because an
* estimation is already in progress.
* @throws IllegalArgumentException if provided quality scores length is
* smaller than minimum required number of evaluations.
*/
public void setQualityScores(final double[] qualityScores) throws LockedException {
// quality scores ignored
}
/**
* Estimates polynomial.
*
* @return estimated polynomial.
* @throws LockedException if robust estimator is locked because an
* estimation is already in progress.
* @throws NotReadyException if provided input data is not enough to start
* the estimation.
* @throws RobustEstimatorException if estimation fails for any other reason
* (i.e. numerical instability, no solution available, etc).
*/
public abstract Polynomial estimate() throws LockedException, NotReadyException, RobustEstimatorException;
/**
* Returns method being used for robust estimation.
*
* @return method being used for robust estimation.
*/
public abstract RobustEstimatorMethod getMethod();
/**
* Creates a robust polynomial estimator using default method.
*
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create() {
return create(DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided degree and default
* method.
*
* @param degree degree of polynomial to be estimated.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(final int degree) {
return create(degree, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided evaluations and
* default method.
*
* @param evaluations collection of polynomial evaluations.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(final List<PolynomialEvaluation> evaluations) {
return create(evaluations, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided listener and default
* method.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(final PolynomialRobustEstimatorListener listener) {
return create(listener, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided degree, evaluations
* and default method.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(final int degree, final List<PolynomialEvaluation> evaluations) {
return create(degree, evaluations, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided degree, listener
* and default method.
*
* @param degree degree of polynomial to be estimated.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(final int degree, final PolynomialRobustEstimatorListener listener) {
return create(degree, listener, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided evaluations,
* listener and default method.
*
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(
final List<PolynomialEvaluation> evaluations, final PolynomialRobustEstimatorListener listener) {
return create(evaluations, listener, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided degree, evaluations,
* listener and default method.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(
final int degree, final List<PolynomialEvaluation> evaluations,
final PolynomialRobustEstimatorListener listener) {
return create(degree, evaluations, listener, DEFAULT_ROBUST_METHOD);
}
/**
* Creates a robust polynomial estimator using provided method.
*
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator();
case LMEDS -> new LMedSPolynomialRobustEstimator();
case MSAC -> new MSACPolynomialRobustEstimator();
case PROMEDS -> new PROMedSPolynomialRobustEstimator();
default -> new PROSACPolynomialRobustEstimator();
};
}
/**
* Creates a robust polynomial estimator using provided degree and method.
*
* @param degree degree of polynomial to be estimated.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(final int degree, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(degree);
case LMEDS -> new LMedSPolynomialRobustEstimator(degree);
case MSAC -> new MSACPolynomialRobustEstimator(degree);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(degree);
default -> new PROSACPolynomialRobustEstimator(degree);
};
}
/**
* Creates a robust polynomial estimator using provided evaluations and
* method.
*
* @param evaluations collection of polynomial evaluations.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(
final List<PolynomialEvaluation> evaluations, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(evaluations);
case LMEDS -> new LMedSPolynomialRobustEstimator(evaluations);
case MSAC -> new MSACPolynomialRobustEstimator(evaluations);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(evaluations);
default -> new PROSACPolynomialRobustEstimator(evaluations);
};
}
/**
* Creates a robust polynomial estimator using provided listener and method.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(
final PolynomialRobustEstimatorListener listener, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(listener);
case LMEDS -> new LMedSPolynomialRobustEstimator(listener);
case MSAC -> new MSACPolynomialRobustEstimator(listener);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(listener);
default -> new PROSACPolynomialRobustEstimator(listener);
};
}
/**
* Creates a robust polynomial estimator using provided degree, evaluations
* and method.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(
final int degree, final List<PolynomialEvaluation> evaluations, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(degree, evaluations);
case LMEDS -> new LMedSPolynomialRobustEstimator(degree, evaluations);
case MSAC -> new MSACPolynomialRobustEstimator(degree, evaluations);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(degree, evaluations);
default -> new PROSACPolynomialRobustEstimator(degree, evaluations);
};
}
/**
* Creates a robust polynomial estimator using provided degree, listener
* and method.
*
* @param degree degree of polynomial to be estimated.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(
final int degree, final PolynomialRobustEstimatorListener listener, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(degree, listener);
case LMEDS -> new LMedSPolynomialRobustEstimator(degree, listener);
case MSAC -> new MSACPolynomialRobustEstimator(degree, listener);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(degree, listener);
default -> new PROSACPolynomialRobustEstimator(degree, listener);
};
}
/**
* Creates a robust polynomial estimator using provided evaluations,
* listener and method.
*
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
*/
public static PolynomialRobustEstimator create(
final List<PolynomialEvaluation> evaluations, final PolynomialRobustEstimatorListener listener,
final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(evaluations, listener);
case LMEDS -> new LMedSPolynomialRobustEstimator(evaluations, listener);
case MSAC -> new MSACPolynomialRobustEstimator(evaluations, listener);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(evaluations, listener);
default -> new PROSACPolynomialRobustEstimator(evaluations, listener);
};
}
/**
* Creates a robust polynomial estimator using provided degree, evaluations,
* listener and method.
*
* @param degree degree of polynomial to be estimated.
* @param evaluations collection of polynomial evaluations.
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param method method of a robust polynomial estimator.
* @return an instance of a robust polynomial estimator.
* @throws IllegalArgumentException if provided degree is less than 1.
*/
public static PolynomialRobustEstimator create(
final int degree, final List<PolynomialEvaluation> evaluations,
final PolynomialRobustEstimatorListener listener, final RobustEstimatorMethod method) {
return switch (method) {
case RANSAC -> new RANSACPolynomialRobustEstimator(degree, evaluations, listener);
case LMEDS -> new LMedSPolynomialRobustEstimator(degree, evaluations, listener);
case MSAC -> new MSACPolynomialRobustEstimator(degree, evaluations, listener);
case PROMEDS -> new PROMedSPolynomialRobustEstimator(degree, evaluations, listener);
default -> new PROSACPolynomialRobustEstimator(degree, evaluations, listener);
};
}
/**
* Computes geometric or algebraic distance between provided polynomial
* and evaluation.
*
* @param eval polynomial evaluation.
* @param polynomial polynomial.
* @return distance.
*/
protected double getDistance(final PolynomialEvaluation eval, final Polynomial polynomial) {
if (useGeometricDistance) {
return getGeometricOrAlgebraicDistance(eval, polynomial);
} else {
return getAlgebraicDistance(eval, polynomial);
}
}
/**
* Computes algebraic distance between provided polynomial and evaluation.
*
* @param eval polynomial evaluation.
* @param polynomial polynomial.
* @return algebraic distance.
*/
protected double getAlgebraicDistance(final PolynomialEvaluation eval, final Polynomial polynomial) {
return switch (eval.getType()) {
case DIRECT_EVALUATION -> getAlgebraicDistance((DirectPolynomialEvaluation) eval, polynomial);
case DERIVATIVE_EVALUATION -> getAlgebraicDistance((DerivativePolynomialEvaluation) eval, polynomial);
case INTEGRAL_EVALUATION -> getAlgebraicDistance((IntegralPolynomialEvaluation) eval, polynomial);
case INTEGRAL_INTERVAL -> getAlgebraicDistance((IntegralIntervalPolynomialEvaluation) eval, polynomial);
};
}
/**
* Computes algebraic distance of between provided polynomial and direct
* evaluation.
*
* @param eval direct polynomial evaluation.
* @param polynomial polynomial.
* @return algebraic distance.
*/
protected double getAlgebraicDistance(final DirectPolynomialEvaluation eval, final Polynomial polynomial) {
final var x = eval.getX();
final var y1 = eval.getEvaluation();
final var y2 = polynomial.evaluate(x);
return Math.abs(y2 - y1);
}
/**
* Computes algebraic distance of a derivative between provided polynomial
* and evaluation.
*
* @param eval derivative polynomial evaluation.
* @param polynomial polynomial.
* @return algebraic distance.
*/
protected double getAlgebraicDistance(final DerivativePolynomialEvaluation eval, final Polynomial polynomial) {
final var x = eval.getX();
final var order = eval.getDerivativeOrder();
final var d1 = eval.getEvaluation();
final var d2 = polynomial.evaluateNthDerivative(x, order);
return Math.abs(d2 - d1);
}
/**
* Computes algebraic distance of an integral between provided polynomial
* and evaluation.
*
* @param eval integration polynomial evaluation.
* @param polynomial polynomial.
* @return algebraic distance.
*/
protected double getAlgebraicDistance(final IntegralPolynomialEvaluation eval, final Polynomial polynomial) {
final var x = eval.getX();
final var order = eval.getIntegralOrder();
final var constants = eval.getConstants();
final var i1 = eval.getEvaluation();
final var i2 = polynomial.nthIntegrationAndReturnNew(order, constants).evaluate(x);
return Math.abs(i2 - i1);
}
/**
* Computes algebraic distance of an integration interval between provided
* polynomial and evaluation.
*
* @param eval integration interval polynomial evaluation.
* @param polynomial polynomial.
* @return algebraic distance.
*/
protected double getAlgebraicDistance(final IntegralIntervalPolynomialEvaluation eval,
final Polynomial polynomial) {
final var startX = eval.getStartX();
final var endX = eval.getEndX();
final var order = eval.getIntegralOrder();
final var constants = eval.getConstants();
final var i1 = eval.getEvaluation();
final var i2 = polynomial.nthOrderIntegrateInterval(startX, endX, order, constants);
return Math.abs(i2 - i1);
}
/**
* Commutes distance of evaluation respect to provided polynomial in
* a geometric sense if evaluation is direct, otherwise returns algebraic
* distance.
*
* @param eval polynomial evaluation.
* @param polynomial polynomial.
* @return geometric distance for direct evaluation or algebraic distance
* otherwise.
*/
protected double getGeometricOrAlgebraicDistance(final PolynomialEvaluation eval, final Polynomial polynomial) {
if (eval.getType() == PolynomialEvaluationType.DIRECT_EVALUATION) {
return getGeometricDistance((DirectPolynomialEvaluation) eval, polynomial);
} else {
return getAlgebraicDistance(eval, polynomial);
}
}
/**
* Computes distance of evaluation respect to provided polynomial in
* a geometric sense by computing a tangent line to polynomial at point x
* and comparing the distance of such line to provided evaluation point.
*
* @param eval polynomial evaluation.
* @param polynomial polynomial.
* @return geometric distance.
*/
protected double getGeometricDistance(final DirectPolynomialEvaluation eval, final Polynomial polynomial) {
final var x = eval.getX();
final var y1 = eval.getEvaluation();
final var y2 = polynomial.evaluate(x);
final var slope = polynomial.evaluateDerivative(x);
final double a;
final double b;
final double c;
if (Math.abs(slope) > 1.0) {
a = 1.0;
b = -1.0 / slope;
c = -x + y2 / slope;
} else {
a = -slope;
b = 1.0;
c = slope * x - y2;
}
final var num = x * a + y1 * b + c;
final var den = Math.sqrt(a * a + b * b);
return Math.abs(num / den);
}
/**
* Sets list of polynomial evaluations.
* This method does not check whether estimator is locked.
*
* @param evaluations list of polynomial evaluations to estimate polynomial.
* @throws IllegalArgumentException if provided list of polynomials is null
* or too small.
*/
private void internalSetEvaluations(final List<PolynomialEvaluation> evaluations) {
if (evaluations == null || evaluations.size() < getMinNumberOfEvaluations()) {
throw new IllegalArgumentException();
}
this.evaluations = evaluations;
}
}