    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.linear.RealMatrix;
    020
    021    /**
    022     * Defines the measurement model for the use with a {@link KalmanFilter}.
    023     *
    024     * @since 3.0
    025     * @version $Id: MeasurementModel.java 1416643 2012-12-03 19:37:14Z tn $
    026     */
    027    public interface MeasurementModel {
    028        /**
    029         * Returns the measurement matrix.
    030         *
    031         * @return the measurement matrix
    032         */
    033        RealMatrix getMeasurementMatrix();
    034
    035        /**
    036         * Returns the measurement noise matrix. This method is called by the {@link KalmanFilter} every
    037         * correction step, so implementations of this interface may return a modified measurement noise
    038         * depending on the current iteration step.
    039         *
    040         * @return the measurement noise matrix
    041         * @see KalmanFilter#correct(double[])
    042         * @see KalmanFilter#correct(org.apache.commons.math3.linear.RealVector)
    043         */
    044        RealMatrix getMeasurementNoise();
    045    }