001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.math3.filter;
018    
019    import org.apache.commons.math3.exception.DimensionMismatchException;
020    import org.apache.commons.math3.exception.NoDataException;
021    import org.apache.commons.math3.exception.NullArgumentException;
022    import org.apache.commons.math3.linear.Array2DRowRealMatrix;
023    import org.apache.commons.math3.linear.RealMatrix;
024    
025    /**
026     * Default implementation of a {@link MeasurementModel} for the use with a {@link KalmanFilter}.
027     *
028     * @since 3.0
029     * @version $Id: DefaultMeasurementModel.java 1416643 2012-12-03 19:37:14Z tn $
030     */
031    public class DefaultMeasurementModel implements MeasurementModel {
032    
033        /**
034         * The measurement matrix, used to associate the measurement vector to the
035         * internal state estimation vector.
036         */
037        private RealMatrix measurementMatrix;
038    
039        /**
040         * The measurement noise covariance matrix.
041         */
042        private RealMatrix measurementNoise;
043    
044        /**
045         * Create a new {@link MeasurementModel}, taking double arrays as input parameters for the
046         * respective measurement matrix and noise.
047         *
048         * @param measMatrix
049         *            the measurement matrix
050         * @param measNoise
051         *            the measurement noise matrix
052         * @throws NullArgumentException
053         *             if any of the input matrices is {@code null}
054         * @throws NoDataException
055         *             if any row / column dimension of the input matrices is zero
056         * @throws DimensionMismatchException
057         *             if any of the input matrices is non-rectangular
058         */
059        public DefaultMeasurementModel(final double[][] measMatrix, final double[][] measNoise)
060                throws NullArgumentException, NoDataException, DimensionMismatchException {
061            this(new Array2DRowRealMatrix(measMatrix), new Array2DRowRealMatrix(measNoise));
062        }
063    
064        /**
065         * Create a new {@link MeasurementModel}, taking {@link RealMatrix} objects
066         * as input parameters for the respective measurement matrix and noise.
067         *
068         * @param measMatrix the measurement matrix
069         * @param measNoise the measurement noise matrix
070         */
071        public DefaultMeasurementModel(final RealMatrix measMatrix, final RealMatrix measNoise) {
072            this.measurementMatrix = measMatrix;
073            this.measurementNoise = measNoise;
074        }
075    
076        /** {@inheritDoc} */
077        public RealMatrix getMeasurementMatrix() {
078            return measurementMatrix;
079        }
080    
081        /** {@inheritDoc} */
082        public RealMatrix getMeasurementNoise() {
083            return measurementNoise;
084        }
085    }