StandardDeviationTimedBodyKinematics.java

/*
 * Copyright (C) 2020 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.inertial.calibration;

import com.irurueta.navigation.inertial.BodyKinematics;
import com.irurueta.units.Acceleration;
import com.irurueta.units.AccelerationConverter;
import com.irurueta.units.AccelerationUnit;
import com.irurueta.units.AngularSpeed;
import com.irurueta.units.AngularSpeedConverter;
import com.irurueta.units.AngularSpeedUnit;
import com.irurueta.units.Time;

import java.io.Serial;
import java.util.Objects;

/**
 * Contains a body kinematics measurement (accelerometer + gyroscope) along with the
 * corresponding timestamp when measure was made and standard deviations of measured
 * specific force and angular rates.
 * Notice that timestamp does not need to be absolute.
 * Usually timestamps are used in sequences of measurements of body kinematics, where
 * the first measurement can have any timestamp value (e.g. zero), and hence the subsequent
 * measurements will have timestamps relative to the first one.
 */
public class StandardDeviationTimedBodyKinematics extends TimedBodyKinematics {

    /**
     * Serialization version. This is used to ensure compatibility of deserialization of permanently stored serialized
     * instances.
     */
    @Serial
    private static final long serialVersionUID = 0L;

    /**
     * Standard deviation of measured specific force expressed in meters per squared
     * second (m/s^2).
     */
    private double specificForceStandardDeviation;

    /**
     * Standard deviation of measured angular rate expressed in radians per second (rad/s).
     */
    private double angularRateStandardDeviation;

    /**
     * Constructor.
     */
    public StandardDeviationTimedBodyKinematics() {
        super();
    }

    /**
     * Constructor.
     *
     * @param kinematics current body kinematics measurement.
     */
    public StandardDeviationTimedBodyKinematics(final BodyKinematics kinematics) {
        super(kinematics);
    }

    /**
     * Constructor.
     *
     * @param timestampSeconds timestamp value expressed in seconds.
     */
    public StandardDeviationTimedBodyKinematics(final double timestampSeconds) {
        super(timestampSeconds);
    }

    /**
     * Constructor.
     *
     * @param timestamp timestamp value.
     */
    public StandardDeviationTimedBodyKinematics(final Time timestamp) {
        super(timestamp);
    }

    /**
     * Constructor.
     *
     * @param kinematics       current body kinematics measurement.
     * @param timestampSeconds timestamp value expressed in seconds.
     */
    public StandardDeviationTimedBodyKinematics(final BodyKinematics kinematics, final double timestampSeconds) {
        super(kinematics, timestampSeconds);
    }

    /**
     * Constructor.
     *
     * @param kinematics current body kinematics measurement.
     * @param timestamp  timestamp value.
     */
    public StandardDeviationTimedBodyKinematics(final BodyKinematics kinematics, final Time timestamp) {
        super(kinematics, timestamp);
    }

    /**
     * Constructor.
     *
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final double specificForceStandardDeviation, final double angularRateStandardDeviation) {
        super();
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final double specificForceStandardDeviation,
            final double angularRateStandardDeviation) {
        super(kinematics);
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param timestampSeconds               timestamp value expressed in seconds.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final double timestampSeconds, final double specificForceStandardDeviation,
            final double angularRateStandardDeviation) {
        super(timestampSeconds);
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param timestamp                      timestamp value.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final Time timestamp, final double specificForceStandardDeviation,
            final double angularRateStandardDeviation) {
        super(timestamp);
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param timestampSeconds               timestamp value expressed in seconds.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final double timestampSeconds, final double specificForceStandardDeviation,
            final double angularRateStandardDeviation) {
        super(kinematics, timestampSeconds);
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param timestamp                      timestamp value.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force expressed in meters per squared
     *                                       second (m/s^2).
     * @param angularRateStandardDeviation   standard deviation of measured angular rate
     *                                       expressed in radians per second (rad/s).
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final Time timestamp, final double specificForceStandardDeviation,
            final double angularRateStandardDeviation) {
        super(kinematics, timestamp);
        setSpecificForceStandardDeviation(specificForceStandardDeviation);
        setAngularRateStandardDeviation(angularRateStandardDeviation);
    }

    /**
     * Constructor.
     *
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final Acceleration specificForceStandardDeviation, final AngularSpeed angularRateStandardDeviation) {
        this(convertAcceleration(specificForceStandardDeviation), convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final Acceleration specificForceStandardDeviation,
            final AngularSpeed angularRateStandardDeviation) {
        this(kinematics, convertAcceleration(specificForceStandardDeviation),
                convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param timestampSeconds               timestamp value expressed in seconds.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final double timestampSeconds, final Acceleration specificForceStandardDeviation,
            final AngularSpeed angularRateStandardDeviation) {
        this(timestampSeconds, convertAcceleration(specificForceStandardDeviation),
                convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param timestamp                      timestamp value.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final Time timestamp, final Acceleration specificForceStandardDeviation,
            final AngularSpeed angularRateStandardDeviation) {
        this(timestamp, convertAcceleration(specificForceStandardDeviation),
                convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param timestampSeconds               timestamp value expressed in seconds.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final double timestampSeconds,
            final Acceleration specificForceStandardDeviation, final AngularSpeed angularRateStandardDeviation) {
        this(kinematics, timestampSeconds, convertAcceleration(specificForceStandardDeviation),
                convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param kinematics                     current body kinematics measurement.
     * @param timestamp                      timestamp value.
     * @param specificForceStandardDeviation standard deviation of measured specific
     *                                       force.
     * @param angularRateStandardDeviation   standard deviation of measured angular
     *                                       rate.
     * @throws IllegalArgumentException if either specific force standard deviation or
     *                                  angular rate standard deviation is negative.
     */
    public StandardDeviationTimedBodyKinematics(
            final BodyKinematics kinematics, final Time timestamp,
            final Acceleration specificForceStandardDeviation, final AngularSpeed angularRateStandardDeviation) {
        this(kinematics, timestamp, convertAcceleration(specificForceStandardDeviation),
                convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Constructor.
     *
     * @param input instance to copy data from.
     */
    public StandardDeviationTimedBodyKinematics(final StandardDeviationTimedBodyKinematics input) {
        copyFrom(input);
    }

    /**
     * Gets standard deviation of measured specific force expressed in meters per squared
     * second (m/s^2).
     *
     * @return standard deviation of measured specific force.
     */
    public double getSpecificForceStandardDeviation() {
        return specificForceStandardDeviation;
    }

    /**
     * Sets standard deviation of measured specific force expressed in meters per squared
     * second (m/s^2).
     *
     * @param specificForceStandardDeviation standard deviation of measured specific force.
     * @throws IllegalArgumentException if provided value is negative.
     */
    public void setSpecificForceStandardDeviation(final double specificForceStandardDeviation) {
        if (specificForceStandardDeviation < 0.0) {
            throw new IllegalArgumentException();
        }

        this.specificForceStandardDeviation = specificForceStandardDeviation;
    }

    /**
     * Gets standard deviation of measured specific force.
     *
     * @return standard deviation of measured specific force.
     */
    public Acceleration getSpecificForceStandardDeviationAsAcceleration() {
        return new Acceleration(specificForceStandardDeviation, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets standard deviation of measured specific force.
     *
     * @param result instance where standard deviation of measured specific force will be
     *               stored.
     */
    public void getSpecificForceStandardDeviationAsAcceleration(final Acceleration result) {
        result.setValue(specificForceStandardDeviation);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets standard deviation of measured specific force.
     *
     * @param specificForceStandardDeviation standard deviation of measured specific force.
     * @throws IllegalArgumentException if provided value is negative.
     */
    public void setSpecificForceStandardDeviation(final Acceleration specificForceStandardDeviation) {
        setSpecificForceStandardDeviation(convertAcceleration(specificForceStandardDeviation));
    }

    /**
     * Gets standard deviation of measured angular rate expressed in radians per second (rad/s).
     *
     * @return standard deviation of measured angular rate.
     */
    public double getAngularRateStandardDeviation() {
        return angularRateStandardDeviation;
    }

    /**
     * Sets standard deviation of measured angular rate expressed in radians per second (rad/s).
     *
     * @param angularRateStandardDeviation standard deviation of measured angular rate.
     * @throws IllegalArgumentException if provided value is negative.
     */
    public void setAngularRateStandardDeviation(final double angularRateStandardDeviation) {
        if (angularRateStandardDeviation < 0.0) {
            throw new IllegalArgumentException();
        }

        this.angularRateStandardDeviation = angularRateStandardDeviation;
    }

    /**
     * Gets standard deviation of measured angular rate.
     *
     * @return standard deviation of measured angular rate.
     */
    public AngularSpeed getAngularRateStandardDeviationAsAngularSpeed() {
        return new AngularSpeed(angularRateStandardDeviation, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets standard deviation of measured angular rate.
     *
     * @param result instance where standard deviation of measured angular rate will be
     *               stored.
     */
    public void getAngularRateStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        result.setValue(angularRateStandardDeviation);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets standard deviation of measured angular rate.
     *
     * @param angularRateStandardDeviation standard deviation of measured angular rate.
     * @throws IllegalArgumentException if provided value is negative.
     */
    public void setAngularRateStandardDeviation(final AngularSpeed angularRateStandardDeviation) {
        setAngularRateStandardDeviation(convertAngularSpeed(angularRateStandardDeviation));
    }

    /**
     * Copies data of provided instance into this instance.
     *
     * @param input instance to copy data from.
     */
    public void copyFrom(final StandardDeviationTimedBodyKinematics input) {
        super.copyFrom(input);
        specificForceStandardDeviation = input.specificForceStandardDeviation;
        angularRateStandardDeviation = input.angularRateStandardDeviation;
    }

    @Override
    public void copyFrom(final TimedBodyKinematics input) {
        copyFrom((StandardDeviationTimedBodyKinematics) input);
    }

    /**
     * Computes and returns hash code for this instance. Hash codes are almost unique
     * values that are useful for fast classification and storage of objects in collections.
     *
     * @return Hash code.
     */
    @Override
    public int hashCode() {
        return Objects.hash(super.hashCode(), specificForceStandardDeviation, angularRateStandardDeviation);
    }

    /**
     * Checks if provided instance has exactly the same contents as this instance.
     *
     * @param other instance to be compared.
     * @return true if both instances are considered to be equal, false otherwise.
     */
    public boolean equals(final StandardDeviationTimedBodyKinematics other) {
        return equals(other, 0.0);
    }

    /**
     * Checks if provided instance has contents similar to this instance up to provided
     * threshold value.
     *
     * @param other     instance to be compared.
     * @param threshold maximum allowed difference between kinematics and standard deviation
     *                  values.
     * @return true if both instances are considered to be equal (up to provided
     * threshold), false otherwise.
     */
    public boolean equals(final StandardDeviationTimedBodyKinematics other, final double threshold) {
        if (other == null) {
            return false;
        }

        return super.equals(other, threshold)
                && Math.abs(specificForceStandardDeviation - other.specificForceStandardDeviation) <= threshold
                && Math.abs(angularRateStandardDeviation - other.angularRateStandardDeviation) <= threshold;
    }

    /**
     * Makes a copy of this instance.
     *
     * @return a copy of this instance.
     * @throws CloneNotSupportedException if clone fails for some reason.
     */
    @Override
    protected Object clone() throws CloneNotSupportedException {
        final var result = (StandardDeviationTimedBodyKinematics) super.clone();
        copyTo(result);
        return result;
    }

    /**
     * Checks if provided object is a StandardDeviationTimedBodyKinematics instance having exactly the
     * same contents as this instance.
     *
     * @param obj object to be compared.
     * @return true if both objects are considered to be equal, false otherwise.
     */
    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        final var other = (StandardDeviationTimedBodyKinematics) obj;
        return equals(other);
    }

    /**
     * Converts provided acceleration to meters per squared second (m/s^2).
     *
     * @param acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return AccelerationConverter.convert(acceleration.getValue().doubleValue(), acceleration.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts provided angular speed to radians per second (rad/s).
     *
     * @param angularSpeed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return AngularSpeedConverter.convert(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit(),
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }
}