RANSACRobustRangingRadioSourceEstimator2D.java
/*
* Copyright (C) 2018 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.navigation.indoor.radiosource;
import com.irurueta.geometry.Point2D;
import com.irurueta.navigation.LockedException;
import com.irurueta.navigation.NotReadyException;
import com.irurueta.navigation.indoor.RadioSource;
import com.irurueta.navigation.indoor.RangingReadingLocated;
import com.irurueta.numerical.robust.RANSACRobustEstimator;
import com.irurueta.numerical.robust.RANSACRobustEstimatorListener;
import com.irurueta.numerical.robust.RobustEstimator;
import com.irurueta.numerical.robust.RobustEstimatorException;
import com.irurueta.numerical.robust.RobustEstimatorMethod;
import java.util.List;
/**
* Robustly estimated 2D position of a radio source (e.g. Wi-Fi
* access point or bluetooth beacon), by discarding outliers using RANSAC
* algorithm.
*
* @param <S> a {@link RadioSource} type.
*/
public class RANSACRobustRangingRadioSourceEstimator2D<S extends RadioSource> extends
RobustRangingRadioSourceEstimator2D<S> {
/**
* Constant defining default threshold on received power (RSSI) expressed in
* dBm's.
*/
public static final double DEFAULT_THRESHOLD = 0.1;
/**
* Minimum value that can be set as threshold.
* Threshold must be strictly greater than 0.0.
*/
public static final double MIN_THRESHOLD = 0.0;
/**
* Indicates that by default inliers will only be computed but not kept.
*/
public static final boolean DEFAULT_COMPUTE_AND_KEEP_INLIERS = false;
/**
* Indicates that by default residuals will only be computed but not kept.
*/
public static final boolean DEFAULT_COMPUTE_AND_KEEP_RESIDUALS = false;
/**
* Threshold to determine whether samples are inliers or not when testing possible solutions.
* The threshold refers to the amount of error on received power (RSSI) expressed
* in dBm's between received value that should have been received on estimated
* iso-tropical model and actual measured value.
*/
private double threshold = DEFAULT_THRESHOLD;
/**
* Indicates whether inliers must be computed and kept.
*/
private boolean computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
/**
* Indicates whether residuals must be computed and kept.
*/
private boolean computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
/**
* Constructor.
*/
public RANSACRobustRangingRadioSourceEstimator2D() {
super();
}
/**
* Constructor.
* Sets radio signal ranging readings belonging to the same radio source.
*
* @param readings radio signal ranging readings belonging to the same
* radio source.
* @throws IllegalArgumentException if readings are not valid.
*/
public RANSACRobustRangingRadioSourceEstimator2D(final List<? extends RangingReadingLocated<S, Point2D>> readings) {
super(readings);
}
/**
* Constructor.
*
* @param listener listener in charge of attending events raised by this instance.
*/
public RANSACRobustRangingRadioSourceEstimator2D(
final RobustRangingRadioSourceEstimatorListener<S, Point2D> listener) {
super(listener);
}
/**
* Constructor.
* Sets radio signal readings belonging to the same radio source.
*
* @param readings radio signal readings belonging to the same radio source.
* @param listener listener in charge of attending events raised by this instance.
* @throws IllegalArgumentException if readings are not valid.
*/
public RANSACRobustRangingRadioSourceEstimator2D(
final List<? extends RangingReadingLocated<S, Point2D>> readings,
final RobustRangingRadioSourceEstimatorListener<S, Point2D> listener) {
super(readings, listener);
}
/**
* Constructor.
*
* @param initialPosition initial position to start the estimation or radio
* source position.
*/
public RANSACRobustRangingRadioSourceEstimator2D(final Point2D initialPosition) {
super(initialPosition);
}
/**
* Constructor.
* Sets radio signal readings belonging to the same radio source.
*
* @param readings radio signal readings belonging to the same radio source.
* @param initialPosition initial position to start the estimation of radio
* source position.
* @throws IllegalArgumentException if readings are not valid.
*/
public RANSACRobustRangingRadioSourceEstimator2D(
final List<? extends RangingReadingLocated<S, Point2D>> readings, final Point2D initialPosition) {
super(readings, initialPosition);
}
/**
* Constructor.
*
* @param initialPosition initial position to start the estimation of radio
* source position.
* @param listener listener in charge of attending events raised by this instance.
*/
public RANSACRobustRangingRadioSourceEstimator2D(
final Point2D initialPosition, final RobustRangingRadioSourceEstimatorListener<S, Point2D> listener) {
super(initialPosition, listener);
}
/**
* Constructor.
* Sets radio signal ranging readings belonging to the same radio source.
*
* @param readings radio signal ranging readings belonging to the same radio source.
* @param initialPosition initial position to start the estimation of radio source
* position.
* @param listener listener in charge of attending events raised by this instance.
* @throws IllegalArgumentException if readings are not valid.
*/
public RANSACRobustRangingRadioSourceEstimator2D(
final List<? extends RangingReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
final RobustRangingRadioSourceEstimatorListener<S, Point2D> listener) {
super(readings, initialPosition, listener);
}
/**
* Gets threshold to determine whether samples are inliers or not when testing possible solutions.
* The threshold refers to the amount of error on ranging distances.
*
* @return threshold to determine whether samples are inliers or not.
*/
public double getThreshold() {
return threshold;
}
/**
* Sets threshold to determine whether samples are inliers or not when testing possible solutions.
* The threshold refers to the amount of error on ranging distances.
*
* @param threshold threshold to determine whether samples are inliers or not.
* @throws IllegalArgumentException if provided value is equal or less than zero.
* @throws LockedException if this estimator is locked.
*/
public void setThreshold(final double threshold) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
if (threshold <= MIN_THRESHOLD) {
throw new IllegalArgumentException();
}
this.threshold = threshold;
}
/**
* Indicates whether inliers must be computed and kept.
*
* @return true if inliers must be computed and kept, false if inliers
* only need to be computed but not kept.
*/
public boolean isComputeAndKeepInliersEnabled() {
return computeAndKeepInliers;
}
/**
* Specifies whether inliers must be computed and kept.
*
* @param computeAndKeepInliers true if inliers must be computed and kept,
* false if inliers only need to be computed but not kept.
* @throws LockedException if this solver is locked.
*/
public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
this.computeAndKeepInliers = computeAndKeepInliers;
}
/**
* Indicates whether residuals must be computed and kept.
*
* @return true if residuals must be computed and kept, false if residuals
* only need to be computed but not kept.
*/
public boolean isComputeAndKeepResidualsEnabled() {
return computeAndKeepResiduals;
}
/**
* Specifies whether residuals must be computed and kept.
*
* @param computeAndKeepResiduals true if residuals must be computed and kept,
* false if residuals only need to be computed but not kept.
* @throws LockedException if this solver is locked.
*/
public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
this.computeAndKeepResiduals = computeAndKeepResiduals;
}
/**
* Robustly estimates position for a radio source.
*
* @throws LockedException if instance is busy during estimation.
* @throws NotReadyException if estimator is not ready.
* @throws RobustEstimatorException if estimation fails for any reason
* (i.e. numerical instability, no solution available, etc).
*/
@SuppressWarnings("DuplicatedCode")
@Override
public void estimate() throws LockedException, NotReadyException, RobustEstimatorException {
if (isLocked()) {
throw new LockedException();
}
if (!isReady()) {
throw new NotReadyException();
}
final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<Solution<Point2D>>() {
@Override
public double getThreshold() {
return threshold;
}
@Override
public int getTotalSamples() {
return readings.size();
}
@Override
public int getSubsetSize() {
return Math.max(preliminarySubsetSize, getMinReadings());
}
@Override
public void estimatePreliminarSolutions(
final int[] samplesIndices, final List<Solution<Point2D>> solutions) {
solvePreliminarySolutions(samplesIndices, solutions);
}
@Override
public double computeResidual(final Solution<Point2D> currentEstimation, final int i) {
return residual(currentEstimation, i);
}
@Override
public boolean isReady() {
return RANSACRobustRangingRadioSourceEstimator2D.this.isReady();
}
@Override
public void onEstimateStart(final RobustEstimator<Solution<Point2D>> estimator) {
// no action needed
}
@Override
public void onEstimateEnd(final RobustEstimator<Solution<Point2D>> estimator) {
// no action needed
}
@Override
public void onEstimateNextIteration(
final RobustEstimator<Solution<Point2D>> estimator, final int iteration) {
if (listener != null) {
listener.onEstimateNextIteration(
RANSACRobustRangingRadioSourceEstimator2D.this, iteration);
}
}
@Override
public void onEstimateProgressChange(
final RobustEstimator<Solution<Point2D>> estimator, final float progress) {
if (listener != null) {
listener.onEstimateProgressChange(
RANSACRobustRangingRadioSourceEstimator2D.this, progress);
}
}
});
try {
locked = true;
if (listener != null) {
listener.onEstimateStart(this);
}
inliersData = null;
innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
innerEstimator.setConfidence(confidence);
innerEstimator.setMaxIterations(maxIterations);
innerEstimator.setProgressDelta(progressDelta);
final var result = innerEstimator.estimate();
inliersData = innerEstimator.getInliersData();
attemptRefine(result);
if (listener != null) {
listener.onEstimateEnd(this);
}
} catch (final com.irurueta.numerical.LockedException e) {
throw new LockedException(e);
} catch (final com.irurueta.numerical.NotReadyException e) {
throw new NotReadyException(e);
} finally {
locked = false;
}
}
/**
* Returns method being used for robust estimation.
*
* @return method being used for robust estimation.
*/
@Override
public RobustEstimatorMethod getMethod() {
return RobustEstimatorMethod.RANSAC;
}
}