LinearFingerprintPositionEstimator3D.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.fingerprint;

import com.irurueta.geometry.InhomogeneousPoint3D;
import com.irurueta.geometry.Point3D;
import com.irurueta.navigation.indoor.RadioSource;
import com.irurueta.navigation.indoor.RadioSourceLocated;
import com.irurueta.navigation.indoor.RssiFingerprint;
import com.irurueta.navigation.indoor.RssiFingerprintLocated;
import com.irurueta.navigation.indoor.RssiReading;

import java.util.List;

/**
 * 2D position estimator based on located fingerprints containing only RSSI readings and
 * having as well prior knowledge of the location of radio sources associated to those
 * readings.
 * This implementation uses a first-order Taylor approximation over provided located
 * fingerprints to determine an approximate position for a non-located fingerprint.
 */
public class LinearFingerprintPositionEstimator3D extends LinearFingerprintPositionEstimator<Point3D> {

    /**
     * Constructor.
     */
    public LinearFingerprintPositionEstimator3D() {
    }

    /**
     * Constructor.
     *
     * @param listener listener in charge of handling events.
     */
    public LinearFingerprintPositionEstimator3D(final FingerprintPositionEstimatorListener<Point3D> listener) {
        super(listener);
    }

    /**
     * Constructor.
     *
     * @param locatedFingerprints located fingerprints containing RSSI readings.
     * @param fingerprint         fingerprint containing readings at an unknown location
     *                            for provided located fingerprints.
     * @param sources             located radio sources.
     * @throws IllegalArgumentException if provided non located fingerprint is null,
     *                                  located fingerprints value is null or there are not enough fingerprints or
     *                                  readings within provided fingerprints (for 3D position estimation 3 located
     *                                  total readings are required among all fingerprints).
     */
    public LinearFingerprintPositionEstimator3D(
            final List<? extends RssiFingerprintLocated<? extends RadioSource,
                    ? extends RssiReading<? extends RadioSource>, Point3D>> locatedFingerprints,
            final RssiFingerprint<? extends RadioSource,
                    ? extends RssiReading<? extends RadioSource>> fingerprint,
            final List<? extends RadioSourceLocated<Point3D>> sources) {
        super(locatedFingerprints, fingerprint, sources);
    }

    /**
     * Constructor.
     *
     * @param locatedFingerprints located fingerprints containing RSSI readings.
     * @param fingerprint         fingerprint containing readings at an unknown location
     *                            for provided located fingerprints.
     * @param sources             located radio sources.
     * @param listener            listener in charge of handling events.
     * @throws IllegalArgumentException if provided non located fingerprint is null,
     *                                  located fingerprints value is null or there are not enough fingerprints or
     *                                  readings within provided fingerprints (for 3D position estimation 3 located
     *                                  total readings are required among all fingerprints).
     */
    public LinearFingerprintPositionEstimator3D(
            final List<? extends RssiFingerprintLocated<? extends RadioSource,
                    ? extends RssiReading<? extends RadioSource>, Point3D>> locatedFingerprints,
            final RssiFingerprint<? extends RadioSource,
                    ? extends RssiReading<? extends RadioSource>> fingerprint,
            final List<? extends RadioSourceLocated<Point3D>> sources,
            final FingerprintPositionEstimatorListener<Point3D> listener) {
        super(locatedFingerprints, fingerprint, sources, listener);
    }

    /**
     * Gets number of dimensions of points.
     *
     * @return number of dimensions of points.
     */
    @Override
    public int getNumberOfDimensions() {
        return Point3D.POINT3D_INHOMOGENEOUS_COORDINATES_LENGTH;
    }

    /**
     * Gets estimated position or null if not available yet.
     *
     * @return estimated position or null.
     */
    @Override
    public Point3D getEstimatedPosition() {
        if (estimatedPositionCoordinates == null) {
            return null;
        }

        final var result = new InhomogeneousPoint3D();
        getEstimatedPosition(result);
        return result;
    }
}